The growing interest in functionalized nanoparticles and their implementa</span></span><span><span><span style="font-family:"">tion in oilfield applications (e.g., drilling...The growing interest in functionalized nanoparticles and their implementa</span></span><span><span><span style="font-family:"">tion in oilfield applications (e.g., drilling fluids and enhanced oil recovery</span></span></span><span><span><span style="font-family:""> (EOR)) facilitate the ongoing efforts to improve their chemical functionalization performance in stabilization of water based or hydrocarbon based nanofluids. Cyclic azasilanes (CAS), substituted 1-aza-2-silacyclopentanes, possess a strained 5-member ring structure. Adjacent Si and N atoms in the ring provide opportunity for highly ef</span></span></span><span style="font-family:Verdana;"></span><span><span><span style="font-family:"">ficient covalent surface functionalization of hydroxylated nanoparticles through a catalyst-free and byproduct-free click <span>reaction. In this work, hydroxylated silica, alumina, diamond, and carbon</span> coated iron core-shell nanoparticles have been studied for monolayer CAS <span>functionalization. Two cyclic azasilanes with different R groups at N atom</span>, such as methyl (CAS-1) and aminoethyl (CAS-2), have been utilized to func<span>tionalize nanoparticles. All reactions were found to readily proceed under</span> mild conditions (room temperature, ambient pressure) during 1 - 2 hours of sonication. CAS functionalized adducts of hydroxylated nanoparticles have been isolated and</span></span></span><span><span><span style="font-family:""> </span></span></span><span><span><span style="font-family:"">their microstructure, composition, solubility and thermal stability have been characterized. As a result, it has been demonstrated, for the first time, that covalent surface modification with cyclic azasilanes can be extended beyond the previously known porous silicon structures to hydroxylated silica, alumina and carbon nanoparticles. The developed methodology was also shown to provide access to the nanoparticles with the hydrophilic or hydrophobic surface functional groups needed to enable oilfield applications (e.g., EOR, tracers, drilling fluids) that require stable water based or hydrocarbon based colloidal systems.展开更多
Fragmentation/disassembly of fiber-like micelles generated by living crystalline-driven self-assembly(CDSA)is usually encountered in aqueous media,which hinders the applications of micelles.Herein,we report the genera...Fragmentation/disassembly of fiber-like micelles generated by living crystalline-driven self-assembly(CDSA)is usually encountered in aqueous media,which hinders the applications of micelles.Herein,we report the generation of uniform fiber-like micelles consisting of a𝜋Л-conjugated oligo(p-phenylenevinylene)core and a crosslinking silica shell with grafted poly(ethylene glycol)(PEG)chains by the combination of living CDSA,silica chemistry and surface grafting-onto strategy.Owing to the presence of crosslinking silica shell and the outmost PEG chains,the resulting micelles exhibit excellent dispersity and colloidal stability in PBS buffer,BSA aqueous solution and upon heating at 80℃ for 2 h without micellar fragmentation/disassembly.The micelles also show negligible cytotoxicity toward both HeLa cervical cancer and HEK239T human embryonic kidney cell lines.Interestingly,micelles with Ln of 156 nm show the“stealth”property with no significant uptake by HeLa cells,whereas some certain amounts of micelles with Ln of 535 nm can penetrate into HeLa cells,showing length-dependent cellular uptake behaviors.These results provide a route to prepare uniform,colloidally stable fiber-like nanostructures with tunable length and functions derived for biomedical applications.展开更多
Since Mr.Tsien brought up his idea of physical mechanics,as a new field in engineering science,to public attention in the early 50's of the 20th century,innumerable application examples of physical mechanics appro...Since Mr.Tsien brought up his idea of physical mechanics,as a new field in engineering science,to public attention in the early 50's of the 20th century,innumerable application examples of physical mechanics approach in diverse fields have manifested its strong vitality increasingly.One of important aspects in applications of physical mechanics is to appropriately choose the microscopic quantity for the system in consideration and build a bridge to connect its relevant microscopic information to its desired macroscopic properties.We present two unique cases of using the physical mechanics approach to study colloidal stability.In the first case we measured the outcomes from artificially induced collisions at individual particle levels,by means of directly observing artificially induced collisions with the aid of optical tweezers.In the second case,by using T-matrix method,the microscopic quantity extinction cross section of the doublet can be accurately evaluated and therefore the measurement range and accuracy of the turbidity methodology for determining the CRC are greatly improved.展开更多
Cellulose nano-crystals(CNC)can be tailored for various value-added applications.However,its use in aqueous systems is hampered by its limited dispersability,especially at a high CNC concentration.In this study,the im...Cellulose nano-crystals(CNC)can be tailored for various value-added applications.However,its use in aqueous systems is hampered by its limited dispersability,especially at a high CNC concentration.In this study,the improvement of CNC colloidal stability by surface chemical grafting with polyacrylic acid(PAA)was investigated,and the zeta potential and the charge density of the chemically modified CNC were analyzed.The results showed that an acrylic dosage of 1%(based on the dry weight of CNC)was sufficient to significantly enhance the colloidal stability.CNC,after chemical grafting with PAA,showed better stability against the increase in storage time or solid content of the aqueous medium,compared with the un-modified CNC.展开更多
Hydroxyapatite(HA)nanoparticles impart outstanding mechanical properties to organicinorganic nanocomposites in bone.Inspired by the composite structure of HA nanoparticles and collagen in bone,a high performance HA/ge...Hydroxyapatite(HA)nanoparticles impart outstanding mechanical properties to organicinorganic nanocomposites in bone.Inspired by the composite structure of HA nanoparticles and collagen in bone,a high performance HA/gelatin nanocomposite was first developed.The nanocomposites have much better mechanical properties(elongation at break 29.9%,tensile strength 90.7 MPa,Young’s modulus 5.24 GPa)than pure gelatin films(elongation at break 9.3%,tensile strength 90.8 MPa,Young’s modulus 2.5 GPa).In addition,the composite films keep a high transmittance in visible wavelength range from 0%to 60%of the HA solid content.These differences in properties are attributed to the homogeneous distribution of HA nanoparticles in the gelatin polymer matrix and the strong interaction between the particle surfaces and the gelatin molecules.This protocol should be promising for HA-based nanocomposites with enhanced mechanical properties for biomedical applications.展开更多
Lipid nanoemulsions are promising nanodrug delivery carriers that can improve the efficacy and safety of paclitaxel(PTX).However,no intravenous lipid emulsion of PTX has been approved for clinical treatment,and system...Lipid nanoemulsions are promising nanodrug delivery carriers that can improve the efficacy and safety of paclitaxel(PTX).However,no intravenous lipid emulsion of PTX has been approved for clinical treatment,and systemic safety profiles have not yet been reported.Here we outline the development of a PTXloaded tumor-targeting intravenous lipid emulsion(PTX Emul)and describe its characteristics,colloidal stability,and systemic safety profiles in terms of acute toxicity,long-term toxicity,and toxicokinetics.We also compare PTX Emul with conventional PTX injection.Results showed that PTX Emul exhibited an ideal average particle size(approximately 160 nm)with narrow size distribution and robust colloidal stability under different conditions.Hypersensitivity reaction and hemolysis tests revealed that PTX Emul did not induce hypersensitivity reactions and had no hemolytic potential.In addition,where the alleviated systemic toxicity of PTX Emul may be attributed to the altered toxicokinetic characteristics in beagle dogs,including the decreased AUC and increased plasma clearance and volume of distribution,PTX Emul alleviated acute and long-term toxicity as evidenced by the enhanced the median lethal dose and approximate lethal dose,moderate body weight change,decreased bone marrow suppression and organ toxicity compared with those under PTX injection at the same dose.A fundamental understanding of the systemic safety profiles,high tumor-targeting efficiency,and superior antitumor activity in vivo of PTX Emul can provide powerful evidence of its therapeutic potential as a future treatment for breast cancer.展开更多
Different amounts of FCC slurry oil and HVGO were added to Tahe atmospheric residue respectively. The colloi- dal stability and asphaltene agglomeration of atmospheric residue and mixed oils were characterized by mean...Different amounts of FCC slurry oil and HVGO were added to Tahe atmospheric residue respectively. The colloi- dal stability and asphaltene agglomeration of atmospheric residue and mixed oils were characterized by means of the mass fraction normalized conductivity and the small-angle X-ray scattering technology （SAXS）. The results indicated that the sta- bility of Tahe atmospheric residue decreased with an increasing amount of these oil fractions. It was found that the decline of the colloidal stability was attributed to the component polarity difference between oil fractions and the atmospheric resi- due. Though the aromaticity of FCC slurry oil was higher than that of HVGO, the polarity of aromatics and resins of FCC slurry oil was lower than those of HVGO. So the degree of the colloidal stability was more seriously destroyed by FCC slurry oil. The dispersion of asphaltenes in Tahe atmospheric residue was changed by adding FCC slurry oil and HVGO. The particle size of as-ohaltenes increased alon~ with the decline of the colloidal stability展开更多
Hydroxyapatite(HA)nanorods were synthesized using a citrate-assisted hydrothermal method.NaH2PO4,Na2HPO4,and Na3PO4 were used as the phosphate sources and the influences of pH value were investigated.The XRD results s...Hydroxyapatite(HA)nanorods were synthesized using a citrate-assisted hydrothermal method.NaH2PO4,Na2HPO4,and Na3PO4 were used as the phosphate sources and the influences of pH value were investigated.The XRD results show that pure hexagonal HA can be synthesized using Na3PO4·12H2O as the phosphate source with the citrate solution pH ranging from 5.0 to 7.6.The zeta potential evaluation demonstrates that as-synthesized HA nanorods are colloidally stable and the aqueous dispersion can be maintained homogenous without any sediment or creaming for more than at least a month.The Ca/P molar ratio of the HA nanorods is about 1.60,indicating that the HA nanorods are calcium-deficient hydroxyapatite.Besides,owing to the excellent colloidal stability and rod-like morphology with a high aspect ratio(>6),the HA aqueous dispersion undergoes a phase transition from an isotropic state to a liquid crystalline state upon increasing the particle concentration to 17wt%.The completely liquid crystalline phase forms when the particle concentration reaches above 30wt%.展开更多
A citrate-assisted hydrothermal method was utilized for the preparation of Sr-substituted hydroxyapatite (HA) nanoparticles.The influences of Sr-substituting degree on the phase identifications,microstructures and col...A citrate-assisted hydrothermal method was utilized for the preparation of Sr-substituted hydroxyapatite (HA) nanoparticles.The influences of Sr-substituting degree on the phase identifications,microstructures and colloidal stability of the resultant products were studied.The experimental results show that the crystalline structures and morphologies of final resultants are significantly changed by controlling the Sr-substituting degree.As the Sr-substituting degree increases,the colloidal stability of samples first increases and then decreases rapidly;the morphology of the product first changes from nanorods to short nanorods rod and then becomes nanowires.Uniform HA hexagonal nanorods with high aspect ratio (>4.0) and excellent aqueous colloidal stability were prepared by 6 h hydrothermal reaction at 180℃ without Sr substitution.The dispersion underwent the phase transition from isotropic to liquid-crystalline state upon the increasing concentration of25wt% and the complete liquid-crystalline phase was achieved when at the concentration above 31wt%.These novel findings provide new insights into the role of Sr substitution on both the citrate-assisted hydroxyapatite crystallization and tailoring of colloidal stability.Moreover,HA liquid crystal behavior was successfully observed,which lays a foundation for the fabrication of macroscopically assembled hydroxyapatite-based biomimetic materials for biomedical applications.展开更多
The extinction cross sections of a system containing two particles are calculated by the T-matrix method, and the results are compared with those of two single particles with single-scattering approximation. The neces...The extinction cross sections of a system containing two particles are calculated by the T-matrix method, and the results are compared with those of two single particles with single-scattering approximation. The necessity of the correction of the refractive indices of water and polystyrene for different incident wavelengths is particularly addressed in the calculation. By this means, the volume fractions allowed for certain accuracy requirements of single-scattering approximation in the light scattering experiment can be evaluated. The volume fractions calculated with corrected refractive indices are compared with those obtained with fixed refractive indices which have been rather commonly used, showing that fixed refractive indices may cause significant error in evaluating multiple scattering effect. The results also give a simple criterion for selecting the incident wavelength and particle size to avoid the ＇blind zone＇ in the turbidity measurement, where the turbidity change is insensitive to aggregation of two particles.展开更多
Infrared solar cells are more efective than normal bandgap solar cells at reducing the spectral loss in the near-infrared region,thus also at broadening the absorption spectra and improving power conversion efciency.P...Infrared solar cells are more efective than normal bandgap solar cells at reducing the spectral loss in the near-infrared region,thus also at broadening the absorption spectra and improving power conversion efciency.PbS colloidal quantum dots(QDs)with tunable bandgap are ideal infrared photovoltaic materials.However,QD solar cell production sufers from small-areabased spin-coating fabrication methods and unstable QD ink.Herein,the QD ink stability mechanism was fully investigated according to Lewis acid–base theory and colloid stability theory.We further studied a mixed solvent system using dimethylformamide and butylamine,compatible with the scalable manufacture of method-blade coating.Based on the ink system,100 cm2 of uniform and dense near-infrared PbS QDs(~0.96 eV)flm was successfully prepared by blade coating.The average efciencies of above absorber-based devices reached 11.14%under AM1.5G illumination,and the 800 nm-fltered efciency achieved 4.28%.Both were the top values among blade coating method based devices.The newly developed ink showed excellent stability,and the device performance based on the ink stored for 7 h was similar to that of fresh ink.The matched solvent system for stable PbS QD ink represents a crucial step toward large area blade coating photoelectric devices.展开更多
This paper presents the study of the effect of multiple ultrasonic impacts on submicron asphaltene aggregates in a toluene/heptane solution,conducted with dynamic light scattering technique.The objects of the study we...This paper presents the study of the effect of multiple ultrasonic impacts on submicron asphaltene aggregates in a toluene/heptane solution,conducted with dynamic light scattering technique.The objects of the study were four samples of asphaltenes obtained from four different oils.For all samples,the change in the average size of the asphaltene submicron aggregates with time was measured after the addition of a precipitant(heptane)to a solution of asphaltenes in toluene at an amount above the threshold concentration.Asphaltene aggregates formed in solution after the addition of the precipitant and were subjected to ultrasonic treatment,which led to the destruction of the asphaltene aggregates.Aggregation of destroyed asphaltenes was observed.The kinetics of this aggregation were similar to the kinetics of aggregation of asphaltenes after the addition of a precipitant.Multiple iterations of asphaltene aggregate destruction in the sample led to a significant change in the kinetics of aggregation:the growth of aggregates slowed and stabilized at a size of approximately 200 nm and 30 nm for the different studied samples.展开更多
Polymer-coated particles and surfaces have widespread applications in various industries ranging from manufacturing to biomedicine.A better understanding of the stability mechanisms underlying these coatings can inspi...Polymer-coated particles and surfaces have widespread applications in various industries ranging from manufacturing to biomedicine.A better understanding of the stability mechanisms underlying these coatings can inspire the design of novel polymer structures and help tune their functions.This can be achieved by quantifying the particle-particle and particle-surface interactions.This paper reviews several common experimental techniques utilized to measure the interactions between polymer-coated particles and surfaces quantitatively.These techniques include atomic force microscopy(AFM),total internal reflection microscopy(TIRM),optical tweezers(OT),and quartz crystal microbalance with dissipation monitoring(QCM-D).The examples of each measuring technique were categorized based on the types of polymer coatings and their associated factors.Additionally,this review demonstrates experimental measurements of interactions involving biological objects.By understanding the fundamental particle-particle and particle-surface interactions,researchers can gain valuable insights to guide the design and functional optimization of polymer-based materials and systems across various applications.展开更多
The outstanding advantages of lightweight and flexibility enable flexible perovskite solar cells(PSCs)to have great application potential in mobile energy devices.Due to the low cost,low-temperature processibility,and...The outstanding advantages of lightweight and flexibility enable flexible perovskite solar cells(PSCs)to have great application potential in mobile energy devices.Due to the low cost,low-temperature processibility,and high electron mobility,SnO_(2) nanocrystals have been widely employed as the electron transport layer in flexible PSCs.To prepare high-quality SnO_(2) layers,a monodispersed nanocrystal solution is normally used.However,the SnO_(2) nanocrystals can easily aggregate,especially after long periods of storage.Herein,we develop a green and cost-effective strategy for the synthesis of high-quality SnO_(2) nanocrystals at low temperatures by introducing small molecules of glycerol,obtaining a stable and well-dispersed SnO_(2)-nanocrystal isopropanol dispersion successfully.Due to the enhanced dispersity and super wettability of this alcohol-based SnO_(2)-nanocrystal solution,large-area smooth and dense SnO_(2) films are easily deposited on the plastic conductive substrate.Furthermore,this contributes to effective charge transfer and suppressed non-radiative recombination at the interface between the SnO_(2) and perovskite layers.As a result,a greatly enhanced power conversion efficiency(PCE)of 21.8%from 19.2%is achieved for small-area flexible PSCs.A large-area 5 cm×5 cm flexible perovskite solar mini-module with a champion PCE of 16.5%and good stability is also demonstrated via this glycerol-modified SnO_(2)-nanocrystal isopropanol dispersion approach.展开更多
The growing interest in valorizing industrial by-products has led researchers to focus on exploring different sources and optimizing collagen extraction conditions over the past decade.While bovine hide,cattle bones,p...The growing interest in valorizing industrial by-products has led researchers to focus on exploring different sources and optimizing collagen extraction conditions over the past decade.While bovine hide,cattle bones,pork,and pig skins remain the most abundant collagen sources,there is a growing trend in the industrial utilization of collagen from non-mammalian species.This review explores alternative marine collagen sourcesand summarizes emerging trends in collagen recovery from marine sources,with a particular focus on environmentally friendly methods.Additionally,this review covers the colloidal structure-forming properties of marine collagens,including foam,film,gel,and emulsion formation.It also highlights the potential and important applications of marine collagen in various food products.Based on the currently reported marine sources,collagens extracted from fish,jellyfish,and sea cucumbers were found to have the highest yield and mostly comprised type-l collagen,while crustaceans and mollusks yielded lower percentages of collagen.Traditional extraction techniques isolate collagen based on acetic acid and pepsin treatment,but they come with drawbacks such as being time-consuming,causing sample destruction,and using solvents.Conversely,marine collagen extracted using conventional methods assisted with ultrasonication resulted in higher yields and strengthened the triple-stranded helical structures.Recently,an increasing number of new applications have been found in the food industry for marine collagens,such as biodegradable film-forming materials,colloid stabilizers,foaming agents,and micro-encapsulating agents.Furthermore,collagen is a modern foodstuff and is extensively used in the beverage,dairy,and meat industries to increase the stability,consistency,and elasticity of products.展开更多
Recently developed lead-free double perovskite nanocrystals(NCs)have been proposed for the possible application in solutionprocessed optoelectronic devices.However,the optoelectronic applications of double perovskite ...Recently developed lead-free double perovskite nanocrystals(NCs)have been proposed for the possible application in solutionprocessed optoelectronic devices.However,the optoelectronic applications of double perovskite NCs have been hampered due to the structural and chemical instability in the presence of polar molecules.Here,we report a facile strategy for the synthesis and purification of Cs_(2)AgBiBr_(6)double perovskite NCs that remained stable even after washing with polar solvent.This is realized with our efficient colloidal route to synthesize Cs_(2)AgBiBr_(6)NCs that involve stable and strongly coordinated precursor such as silvertrioctyl phosphine complex together with bismuth neodecanoate,which leads to a significantly improved chemical and colloidal stability.Using layer-by-layer solid-state ligand exchange technique,a compact and crack-free thin film of Cs_(2)AgBiBr_(6)NCs were fabricated.Finally,perovskite solar cells consisting of Cs_(2)AgBiBr_(6)as an absorber layer were fabricated and tested.展开更多
There is no doubt about the potential technological significance of nanofluids. The promising application areas have been identified as effective heat transfer fluids, contrast agents in magnetic resonance imaging, ma...There is no doubt about the potential technological significance of nanofluids. The promising application areas have been identified as effective heat transfer fluids, contrast agents in magnetic resonance imaging, magnetohyperthermia treatment, precursors to high performance nanocomposites and ordered nanostructures. However, commercial applications are rare, in part due to the limited understanding of the nanofluid fundamentals such as colloid stability, phase diagrams and rheology. This paper intends to provide a brief overview of the scientific disciplines that are important to nanofluids, and the interconnection among different disciplines in order to gain a perspective on the future development of this intriguing area.展开更多
Superdisintegrants are cross-linked polymers that can be used as dispersants for fast release of drug nanoparticles from nanocomposite microparticles during in vitro and in vivo dissolution. Currently avail- able supe...Superdisintegrants are cross-linked polymers that can be used as dispersants for fast release of drug nanoparticles from nanocomposite microparticles during in vitro and in vivo dissolution. Currently avail- able superdisintegrant particles have average sizes of approximately 5-130 μm, which are too big for drug nanocomposite applications. Hence, production of stable superdisintegrant suspensions with less than 5 μm particles is desirable. Here, we explore the preparation of colloidal suspensions of anionic and nonionic superdisintegrants using a wet stirred media mill and assess their physical stability. Sodium starch glycolate （SSG） and crospovidone （CP） were selected as representative anionic and nonionic superdisintegrants, and hydroxypropyl cellulose （HPC） and sodium dodecyl sulfate （SDS） were used as a steric stabilizer and a wetting agent/stabilizer, respectively. Particle sizing, scanning electron microscopy, and zeta potential measurements were used to characterize the suspensions. Colloidal superdisintegrant suspensions were prepared reproducibly. The extensive particle breakage was attributed to the swelling-induced softening in water. SSG suspensions were stable even in the absence of stabilizers, whereas CP suspensions required HPC-SDS for minimizing particle aggregation. These findings were explained by the higher absolute （negative） zeta potential of the suspensions of the anionic superdisintegrant （SSG） as compared with those of the nonionic superdisintegrant （CP）.展开更多
The self-assembly of nanoparticles has attracted a vast amount of attention due to the ability of the nanostructure to control light at the sub-wavelength scale,along with consequent strong electromagnetic field enhan...The self-assembly of nanoparticles has attracted a vast amount of attention due to the ability of the nanostructure to control light at the sub-wavelength scale,along with consequent strong electromagnetic field enhancement.However,most approaches developed for the formation of discrete assemblies are limited to a single and homogeneous system,and incorporation of larger or asymmetrical nanoparticles into assemblies with high purity remains a key challenge.Here,a simple and versatile approach to assemble nanoparticles of different sizes,shapes,and materials into various discrete homo-or hetero-structures using only two complementary deoxyribonucleic acid(DNA)strands is presented.First,surface functionalisation using DNA and alkyl-polyethylene glycol(PEG)enables transformation of as-synthesised nanoparticles into readily usable plasmonic building blocks for self-assembly.Optimisation of the DNA coverage enables the production of different assembly types,such as homo-and hetero-dimers,trimers and tetramers and core-satellite structures,which are produced in high purity using electrophoresis purification.The approach is extended from purely plasmonic structures to incorporate(luminescent)semiconductor nanoparticles for formation of hybrid assemblies.The deposited assemblies form a high yield of specific geometrical arrangements,attributed to the van der Waals attraction between particles.This method will enable the development of new complex colloidal nanoassemblies for biological and optical applications.展开更多
Polymer chain architectures play a crucial role in the physical properties of polymers and this unique phenomenon has been recognized as the topological effects.As one of the most representative architectures,macrocyc...Polymer chain architectures play a crucial role in the physical properties of polymers and this unique phenomenon has been recognized as the topological effects.As one of the most representative architectures,macrocyclic polymers characterized by the endless topology have received extensive attention due to their distinct physical properties as compared to the linear counterparts.To understand these differences and unravel the underlying mechanisms,there is a long pursuit to efficiently fabricate macrocyclic polymers.To date,both ring-closing and ring-expansion strategies have been developed,which drastically elevates the accessibility of macrocyclic polymers.The improved availability of macrocyclic polymers enables the further investigation of the biomedical applications and the preliminary results suggest that macrocyclic polymers outperform their linear analogs in terms of improving gene delivery efficiency,elevating blood circulation time,and enhancing colloidal stability of nanoparticles.展开更多
文摘The growing interest in functionalized nanoparticles and their implementa</span></span><span><span><span style="font-family:"">tion in oilfield applications (e.g., drilling fluids and enhanced oil recovery</span></span></span><span><span><span style="font-family:""> (EOR)) facilitate the ongoing efforts to improve their chemical functionalization performance in stabilization of water based or hydrocarbon based nanofluids. Cyclic azasilanes (CAS), substituted 1-aza-2-silacyclopentanes, possess a strained 5-member ring structure. Adjacent Si and N atoms in the ring provide opportunity for highly ef</span></span></span><span style="font-family:Verdana;"></span><span><span><span style="font-family:"">ficient covalent surface functionalization of hydroxylated nanoparticles through a catalyst-free and byproduct-free click <span>reaction. In this work, hydroxylated silica, alumina, diamond, and carbon</span> coated iron core-shell nanoparticles have been studied for monolayer CAS <span>functionalization. Two cyclic azasilanes with different R groups at N atom</span>, such as methyl (CAS-1) and aminoethyl (CAS-2), have been utilized to func<span>tionalize nanoparticles. All reactions were found to readily proceed under</span> mild conditions (room temperature, ambient pressure) during 1 - 2 hours of sonication. CAS functionalized adducts of hydroxylated nanoparticles have been isolated and</span></span></span><span><span><span style="font-family:""> </span></span></span><span><span><span style="font-family:"">their microstructure, composition, solubility and thermal stability have been characterized. As a result, it has been demonstrated, for the first time, that covalent surface modification with cyclic azasilanes can be extended beyond the previously known porous silicon structures to hydroxylated silica, alumina and carbon nanoparticles. The developed methodology was also shown to provide access to the nanoparticles with the hydrophilic or hydrophobic surface functional groups needed to enable oilfield applications (e.g., EOR, tracers, drilling fluids) that require stable water based or hydrocarbon based colloidal systems.
基金The authors are thankful for financial support from National Science Foundation for Distinguished Young Scholars(51825304)National Natural Science Foundation of China(52122314,51873229 and 51961145103)+3 种基金the project of Bureau of International Cooperation,CAS(121731KYSB20200006)Youth Innovation Promotion Association of CAS(Y2020062)Shanghai Scientific and Technological Innovation Project(19ZR1468400,19590750400,20JC1415400 and 21520780100)Innovation Program of Shanghai Municipal Education Commission(2019-01-07-00-05-E00012).
文摘Fragmentation/disassembly of fiber-like micelles generated by living crystalline-driven self-assembly(CDSA)is usually encountered in aqueous media,which hinders the applications of micelles.Herein,we report the generation of uniform fiber-like micelles consisting of a𝜋Л-conjugated oligo(p-phenylenevinylene)core and a crosslinking silica shell with grafted poly(ethylene glycol)(PEG)chains by the combination of living CDSA,silica chemistry and surface grafting-onto strategy.Owing to the presence of crosslinking silica shell and the outmost PEG chains,the resulting micelles exhibit excellent dispersity and colloidal stability in PBS buffer,BSA aqueous solution and upon heating at 80℃ for 2 h without micellar fragmentation/disassembly.The micelles also show negligible cytotoxicity toward both HeLa cervical cancer and HEK239T human embryonic kidney cell lines.Interestingly,micelles with Ln of 156 nm show the“stealth”property with no significant uptake by HeLa cells,whereas some certain amounts of micelles with Ln of 535 nm can penetrate into HeLa cells,showing length-dependent cellular uptake behaviors.These results provide a route to prepare uniform,colloidally stable fiber-like nanostructures with tunable length and functions derived for biomedical applications.
基金supported by the National Natural Science Foundation of China (Grant Nos.11172302,10972217 and 11032011)the Knowledge Innovation Program of the Chinese Academy of Sciences(Grant No.KJCX2-YW-L08)
文摘Since Mr.Tsien brought up his idea of physical mechanics,as a new field in engineering science,to public attention in the early 50's of the 20th century,innumerable application examples of physical mechanics approach in diverse fields have manifested its strong vitality increasingly.One of important aspects in applications of physical mechanics is to appropriately choose the microscopic quantity for the system in consideration and build a bridge to connect its relevant microscopic information to its desired macroscopic properties.We present two unique cases of using the physical mechanics approach to study colloidal stability.In the first case we measured the outcomes from artificially induced collisions at individual particle levels,by means of directly observing artificially induced collisions with the aid of optical tweezers.In the second case,by using T-matrix method,the microscopic quantity extinction cross section of the doublet can be accurately evaluated and therefore the measurement range and accuracy of the turbidity methodology for determining the CRC are greatly improved.
基金support from the Tianjin Municipal Science and Technology Commission (Grant No.12ZCZDGX01100).
文摘Cellulose nano-crystals(CNC)can be tailored for various value-added applications.However,its use in aqueous systems is hampered by its limited dispersability,especially at a high CNC concentration.In this study,the improvement of CNC colloidal stability by surface chemical grafting with polyacrylic acid(PAA)was investigated,and the zeta potential and the charge density of the chemically modified CNC were analyzed.The results showed that an acrylic dosage of 1%(based on the dry weight of CNC)was sufficient to significantly enhance the colloidal stability.CNC,after chemical grafting with PAA,showed better stability against the increase in storage time or solid content of the aqueous medium,compared with the un-modified CNC.
基金Funded by the Natural Science Foundation of Hubei Province(No.2018CFB710)the Opening Fund of Hubei Provincial Key Laboratory of Green Materials for Light Industry(No.202107B07)Hubei University of Technology。
文摘Hydroxyapatite(HA)nanoparticles impart outstanding mechanical properties to organicinorganic nanocomposites in bone.Inspired by the composite structure of HA nanoparticles and collagen in bone,a high performance HA/gelatin nanocomposite was first developed.The nanocomposites have much better mechanical properties(elongation at break 29.9%,tensile strength 90.7 MPa,Young’s modulus 5.24 GPa)than pure gelatin films(elongation at break 9.3%,tensile strength 90.8 MPa,Young’s modulus 2.5 GPa).In addition,the composite films keep a high transmittance in visible wavelength range from 0%to 60%of the HA solid content.These differences in properties are attributed to the homogeneous distribution of HA nanoparticles in the gelatin polymer matrix and the strong interaction between the particle surfaces and the gelatin molecules.This protocol should be promising for HA-based nanocomposites with enhanced mechanical properties for biomedical applications.
基金supported by the National Science and Technology Major Project of China(Grant No.:2018ZX09711001)Beijing Nova Program(Grant No.:Z211100002121127)+2 种基金Beijing Natural Science Foundation(Grant No.:L212059)Fundamental Research Funds for the Central Universities(Grant No.:3332021101)CAMS Innovation Fund for Medical Sciences(CIFMS,Grant No.:2022-I2M-JB-011).
文摘Lipid nanoemulsions are promising nanodrug delivery carriers that can improve the efficacy and safety of paclitaxel(PTX).However,no intravenous lipid emulsion of PTX has been approved for clinical treatment,and systemic safety profiles have not yet been reported.Here we outline the development of a PTXloaded tumor-targeting intravenous lipid emulsion(PTX Emul)and describe its characteristics,colloidal stability,and systemic safety profiles in terms of acute toxicity,long-term toxicity,and toxicokinetics.We also compare PTX Emul with conventional PTX injection.Results showed that PTX Emul exhibited an ideal average particle size(approximately 160 nm)with narrow size distribution and robust colloidal stability under different conditions.Hypersensitivity reaction and hemolysis tests revealed that PTX Emul did not induce hypersensitivity reactions and had no hemolytic potential.In addition,where the alleviated systemic toxicity of PTX Emul may be attributed to the altered toxicokinetic characteristics in beagle dogs,including the decreased AUC and increased plasma clearance and volume of distribution,PTX Emul alleviated acute and long-term toxicity as evidenced by the enhanced the median lethal dose and approximate lethal dose,moderate body weight change,decreased bone marrow suppression and organ toxicity compared with those under PTX injection at the same dose.A fundamental understanding of the systemic safety profiles,high tumor-targeting efficiency,and superior antitumor activity in vivo of PTX Emul can provide powerful evidence of its therapeutic potential as a future treatment for breast cancer.
基金Financial support was provided by the Ministry of Science and Technology of China through the National Basic Research Program (Grant No. 2010CB217807)
文摘Different amounts of FCC slurry oil and HVGO were added to Tahe atmospheric residue respectively. The colloi- dal stability and asphaltene agglomeration of atmospheric residue and mixed oils were characterized by means of the mass fraction normalized conductivity and the small-angle X-ray scattering technology （SAXS）. The results indicated that the sta- bility of Tahe atmospheric residue decreased with an increasing amount of these oil fractions. It was found that the decline of the colloidal stability was attributed to the component polarity difference between oil fractions and the atmospheric resi- due. Though the aromaticity of FCC slurry oil was higher than that of HVGO, the polarity of aromatics and resins of FCC slurry oil was lower than those of HVGO. So the degree of the colloidal stability was more seriously destroyed by FCC slurry oil. The dispersion of asphaltenes in Tahe atmospheric residue was changed by adding FCC slurry oil and HVGO. The particle size of as-ohaltenes increased alon~ with the decline of the colloidal stability
基金Funded by the National Natural Science Foundation of China(Nos.21203059&51402097)the Natural Science Foundation of Hubei Province(No.2018CFB710)+1 种基金the National Training Program of Innovation and Entrepreneurship for Undergraduates(201710500010)the Opening Fund(No.201907B12)of Hubei Provincial Key Laboratory of Green Materials for Light Industry,Hubei University of Technology。
文摘Hydroxyapatite(HA)nanorods were synthesized using a citrate-assisted hydrothermal method.NaH2PO4,Na2HPO4,and Na3PO4 were used as the phosphate sources and the influences of pH value were investigated.The XRD results show that pure hexagonal HA can be synthesized using Na3PO4·12H2O as the phosphate source with the citrate solution pH ranging from 5.0 to 7.6.The zeta potential evaluation demonstrates that as-synthesized HA nanorods are colloidally stable and the aqueous dispersion can be maintained homogenous without any sediment or creaming for more than at least a month.The Ca/P molar ratio of the HA nanorods is about 1.60,indicating that the HA nanorods are calcium-deficient hydroxyapatite.Besides,owing to the excellent colloidal stability and rod-like morphology with a high aspect ratio(>6),the HA aqueous dispersion undergoes a phase transition from an isotropic state to a liquid crystalline state upon increasing the particle concentration to 17wt%.The completely liquid crystalline phase forms when the particle concentration reaches above 30wt%.
基金the National Natural Science Foundation of China(51402097)the Natural Science Foundation of Hubei Province(No.2018CFB710)。
文摘A citrate-assisted hydrothermal method was utilized for the preparation of Sr-substituted hydroxyapatite (HA) nanoparticles.The influences of Sr-substituting degree on the phase identifications,microstructures and colloidal stability of the resultant products were studied.The experimental results show that the crystalline structures and morphologies of final resultants are significantly changed by controlling the Sr-substituting degree.As the Sr-substituting degree increases,the colloidal stability of samples first increases and then decreases rapidly;the morphology of the product first changes from nanorods to short nanorods rod and then becomes nanowires.Uniform HA hexagonal nanorods with high aspect ratio (>4.0) and excellent aqueous colloidal stability were prepared by 6 h hydrothermal reaction at 180℃ without Sr substitution.The dispersion underwent the phase transition from isotropic to liquid-crystalline state upon the increasing concentration of25wt% and the complete liquid-crystalline phase was achieved when at the concentration above 31wt%.These novel findings provide new insights into the role of Sr substitution on both the citrate-assisted hydroxyapatite crystallization and tailoring of colloidal stability.Moreover,HA liquid crystal behavior was successfully observed,which lays a foundation for the fabrication of macroscopically assembled hydroxyapatite-based biomimetic materials for biomedical applications.
基金Supported by the National Natural Science Foundation of China under Grand Nos 10672173 and 10332050, and the China Postdoctoral Science Foundation.
文摘The extinction cross sections of a system containing two particles are calculated by the T-matrix method, and the results are compared with those of two single particles with single-scattering approximation. The necessity of the correction of the refractive indices of water and polystyrene for different incident wavelengths is particularly addressed in the calculation. By this means, the volume fractions allowed for certain accuracy requirements of single-scattering approximation in the light scattering experiment can be evaluated. The volume fractions calculated with corrected refractive indices are compared with those obtained with fixed refractive indices which have been rather commonly used, showing that fixed refractive indices may cause significant error in evaluating multiple scattering effect. The results also give a simple criterion for selecting the incident wavelength and particle size to avoid the ＇blind zone＇ in the turbidity measurement, where the turbidity change is insensitive to aggregation of two particles.
基金HS acknowledges the financial support from the National Natural Science Foundation of China(Grant No.62374065)the Interdisciplinary Research promotion of HUST(No.2023JCYJ040)+4 种基金the Innovation Project of Optics Valley Laboratory(No.OVL2021BG008)the Program of Science Technology of Wenzhou City(No.G20210011)HH acknowledges the fnancial support from the Innovation and Technology Commission(No.MHP/104/21)the Shenzhen Science Technology and Innovation Commission(No.JCYJ20210324125612035)the City University of Hong Kong(Nos.9360140,7005720,9667229,9680331,7005580,and 9678291)。
文摘Infrared solar cells are more efective than normal bandgap solar cells at reducing the spectral loss in the near-infrared region,thus also at broadening the absorption spectra and improving power conversion efciency.PbS colloidal quantum dots(QDs)with tunable bandgap are ideal infrared photovoltaic materials.However,QD solar cell production sufers from small-areabased spin-coating fabrication methods and unstable QD ink.Herein,the QD ink stability mechanism was fully investigated according to Lewis acid–base theory and colloid stability theory.We further studied a mixed solvent system using dimethylformamide and butylamine,compatible with the scalable manufacture of method-blade coating.Based on the ink system,100 cm2 of uniform and dense near-infrared PbS QDs(~0.96 eV)flm was successfully prepared by blade coating.The average efciencies of above absorber-based devices reached 11.14%under AM1.5G illumination,and the 800 nm-fltered efciency achieved 4.28%.Both were the top values among blade coating method based devices.The newly developed ink showed excellent stability,and the device performance based on the ink stored for 7 h was similar to that of fresh ink.The matched solvent system for stable PbS QD ink represents a crucial step toward large area blade coating photoelectric devices.
基金The author of the article would like to thank Alexey D.Yapryntsev(Kurnakov Institute of General and Inorganic Chemistry of the Russian Academy of Sciences)for studying the samples by scanning electron microscopy.The author thanks the staff of the A.E.Arbuzov Institute of Organic and Physical Chemistry,“Kazan Scientific Center of Russian Academy of Sciences”,laboratory of Chemistry and Geochemistry of Petroleum and organizers of International Conference on Petroleum Phase Behavior&Fouling“PetroPhase2017”for providing samples of asphaltenes and resins.This work was performed within the framework of the state task(by Ministry of Science and Higher Education of the Russian Federation)of the Oil and Gas Research Institute of Russian Academy of Sciences(Project No.122022800364-6).
文摘This paper presents the study of the effect of multiple ultrasonic impacts on submicron asphaltene aggregates in a toluene/heptane solution,conducted with dynamic light scattering technique.The objects of the study were four samples of asphaltenes obtained from four different oils.For all samples,the change in the average size of the asphaltene submicron aggregates with time was measured after the addition of a precipitant(heptane)to a solution of asphaltenes in toluene at an amount above the threshold concentration.Asphaltene aggregates formed in solution after the addition of the precipitant and were subjected to ultrasonic treatment,which led to the destruction of the asphaltene aggregates.Aggregation of destroyed asphaltenes was observed.The kinetics of this aggregation were similar to the kinetics of aggregation of asphaltenes after the addition of a precipitant.Multiple iterations of asphaltene aggregate destruction in the sample led to a significant change in the kinetics of aggregation:the growth of aggregates slowed and stabilized at a size of approximately 200 nm and 30 nm for the different studied samples.
文摘Polymer-coated particles and surfaces have widespread applications in various industries ranging from manufacturing to biomedicine.A better understanding of the stability mechanisms underlying these coatings can inspire the design of novel polymer structures and help tune their functions.This can be achieved by quantifying the particle-particle and particle-surface interactions.This paper reviews several common experimental techniques utilized to measure the interactions between polymer-coated particles and surfaces quantitatively.These techniques include atomic force microscopy(AFM),total internal reflection microscopy(TIRM),optical tweezers(OT),and quartz crystal microbalance with dissipation monitoring(QCM-D).The examples of each measuring technique were categorized based on the types of polymer coatings and their associated factors.Additionally,this review demonstrates experimental measurements of interactions involving biological objects.By understanding the fundamental particle-particle and particle-surface interactions,researchers can gain valuable insights to guide the design and functional optimization of polymer-based materials and systems across various applications.
基金supported by the National Key Research and Development Plan(No.2019YFE0107200)the National Natural Science Foundation of China(Nos.22279099,52202292,and 52172230)+3 种基金Guangdong Basic and Applied Basic Research Fund(No.2021B1515120003)the NSF of Hubei Province(No.2021CFB051)the Fundamental Research Funds for the Central Universities(No.WUT:2023IVA074)the National Research Foundation of Korea(NRF)(No.2019K1A3A1A61091345).
文摘The outstanding advantages of lightweight and flexibility enable flexible perovskite solar cells(PSCs)to have great application potential in mobile energy devices.Due to the low cost,low-temperature processibility,and high electron mobility,SnO_(2) nanocrystals have been widely employed as the electron transport layer in flexible PSCs.To prepare high-quality SnO_(2) layers,a monodispersed nanocrystal solution is normally used.However,the SnO_(2) nanocrystals can easily aggregate,especially after long periods of storage.Herein,we develop a green and cost-effective strategy for the synthesis of high-quality SnO_(2) nanocrystals at low temperatures by introducing small molecules of glycerol,obtaining a stable and well-dispersed SnO_(2)-nanocrystal isopropanol dispersion successfully.Due to the enhanced dispersity and super wettability of this alcohol-based SnO_(2)-nanocrystal solution,large-area smooth and dense SnO_(2) films are easily deposited on the plastic conductive substrate.Furthermore,this contributes to effective charge transfer and suppressed non-radiative recombination at the interface between the SnO_(2) and perovskite layers.As a result,a greatly enhanced power conversion efficiency(PCE)of 21.8%from 19.2%is achieved for small-area flexible PSCs.A large-area 5 cm×5 cm flexible perovskite solar mini-module with a champion PCE of 16.5%and good stability is also demonstrated via this glycerol-modified SnO_(2)-nanocrystal isopropanol dispersion approach.
基金funded by the"Pioneer"and"Leading Goose"R&D Program of Zhejiang Province(2023C02044).
文摘The growing interest in valorizing industrial by-products has led researchers to focus on exploring different sources and optimizing collagen extraction conditions over the past decade.While bovine hide,cattle bones,pork,and pig skins remain the most abundant collagen sources,there is a growing trend in the industrial utilization of collagen from non-mammalian species.This review explores alternative marine collagen sourcesand summarizes emerging trends in collagen recovery from marine sources,with a particular focus on environmentally friendly methods.Additionally,this review covers the colloidal structure-forming properties of marine collagens,including foam,film,gel,and emulsion formation.It also highlights the potential and important applications of marine collagen in various food products.Based on the currently reported marine sources,collagens extracted from fish,jellyfish,and sea cucumbers were found to have the highest yield and mostly comprised type-l collagen,while crustaceans and mollusks yielded lower percentages of collagen.Traditional extraction techniques isolate collagen based on acetic acid and pepsin treatment,but they come with drawbacks such as being time-consuming,causing sample destruction,and using solvents.Conversely,marine collagen extracted using conventional methods assisted with ultrasonication resulted in higher yields and strengthened the triple-stranded helical structures.Recently,an increasing number of new applications have been found in the food industry for marine collagens,such as biodegradable film-forming materials,colloid stabilizers,foaming agents,and micro-encapsulating agents.Furthermore,collagen is a modern foodstuff and is extensively used in the beverage,dairy,and meat industries to increase the stability,consistency,and elasticity of products.
文摘Recently developed lead-free double perovskite nanocrystals(NCs)have been proposed for the possible application in solutionprocessed optoelectronic devices.However,the optoelectronic applications of double perovskite NCs have been hampered due to the structural and chemical instability in the presence of polar molecules.Here,we report a facile strategy for the synthesis and purification of Cs_(2)AgBiBr_(6)double perovskite NCs that remained stable even after washing with polar solvent.This is realized with our efficient colloidal route to synthesize Cs_(2)AgBiBr_(6)NCs that involve stable and strongly coordinated precursor such as silvertrioctyl phosphine complex together with bismuth neodecanoate,which leads to a significantly improved chemical and colloidal stability.Using layer-by-layer solid-state ligand exchange technique,a compact and crack-free thin film of Cs_(2)AgBiBr_(6)NCs were fabricated.Finally,perovskite solar cells consisting of Cs_(2)AgBiBr_(6)as an absorber layer were fabricated and tested.
基金The Dow Chemical Companyfor its support of the writing of this manuscript
文摘There is no doubt about the potential technological significance of nanofluids. The promising application areas have been identified as effective heat transfer fluids, contrast agents in magnetic resonance imaging, magnetohyperthermia treatment, precursors to high performance nanocomposites and ordered nanostructures. However, commercial applications are rare, in part due to the limited understanding of the nanofluid fundamentals such as colloid stability, phase diagrams and rheology. This paper intends to provide a brief overview of the scientific disciplines that are important to nanofluids, and the interconnection among different disciplines in order to gain a perspective on the future development of this intriguing area.
基金financial support from the U.S.National Science Foundation Engineering Research Center for Structured Organic Particulate Systems(NSF ERC for SOPS) through the Grant EEC-0540855
文摘Superdisintegrants are cross-linked polymers that can be used as dispersants for fast release of drug nanoparticles from nanocomposite microparticles during in vitro and in vivo dissolution. Currently avail- able superdisintegrant particles have average sizes of approximately 5-130 μm, which are too big for drug nanocomposite applications. Hence, production of stable superdisintegrant suspensions with less than 5 μm particles is desirable. Here, we explore the preparation of colloidal suspensions of anionic and nonionic superdisintegrants using a wet stirred media mill and assess their physical stability. Sodium starch glycolate （SSG） and crospovidone （CP） were selected as representative anionic and nonionic superdisintegrants, and hydroxypropyl cellulose （HPC） and sodium dodecyl sulfate （SDS） were used as a steric stabilizer and a wetting agent/stabilizer, respectively. Particle sizing, scanning electron microscopy, and zeta potential measurements were used to characterize the suspensions. Colloidal superdisintegrant suspensions were prepared reproducibly. The extensive particle breakage was attributed to the swelling-induced softening in water. SSG suspensions were stable even in the absence of stabilizers, whereas CP suspensions required HPC-SDS for minimizing particle aggregation. These findings were explained by the higher absolute （negative） zeta potential of the suspensions of the anionic superdisintegrant （SSG） as compared with those of the nonionic superdisintegrant （CP）.
基金This work was supported by the Australian Research Council(ARC)Grants for the ARC Centre of Excellence in Exciton Science,CE170100026 and DP140103011.
文摘The self-assembly of nanoparticles has attracted a vast amount of attention due to the ability of the nanostructure to control light at the sub-wavelength scale,along with consequent strong electromagnetic field enhancement.However,most approaches developed for the formation of discrete assemblies are limited to a single and homogeneous system,and incorporation of larger or asymmetrical nanoparticles into assemblies with high purity remains a key challenge.Here,a simple and versatile approach to assemble nanoparticles of different sizes,shapes,and materials into various discrete homo-or hetero-structures using only two complementary deoxyribonucleic acid(DNA)strands is presented.First,surface functionalisation using DNA and alkyl-polyethylene glycol(PEG)enables transformation of as-synthesised nanoparticles into readily usable plasmonic building blocks for self-assembly.Optimisation of the DNA coverage enables the production of different assembly types,such as homo-and hetero-dimers,trimers and tetramers and core-satellite structures,which are produced in high purity using electrophoresis purification.The approach is extended from purely plasmonic structures to incorporate(luminescent)semiconductor nanoparticles for formation of hybrid assemblies.The deposited assemblies form a high yield of specific geometrical arrangements,attributed to the van der Waals attraction between particles.This method will enable the development of new complex colloidal nanoassemblies for biological and optical applications.
基金supported by the National Natural Science Foundation of China(51690150,51690154,21674103,51673179)International S&T Cooperation Program of China of MOST(2016YFE0129700)
文摘Polymer chain architectures play a crucial role in the physical properties of polymers and this unique phenomenon has been recognized as the topological effects.As one of the most representative architectures,macrocyclic polymers characterized by the endless topology have received extensive attention due to their distinct physical properties as compared to the linear counterparts.To understand these differences and unravel the underlying mechanisms,there is a long pursuit to efficiently fabricate macrocyclic polymers.To date,both ring-closing and ring-expansion strategies have been developed,which drastically elevates the accessibility of macrocyclic polymers.The improved availability of macrocyclic polymers enables the further investigation of the biomedical applications and the preliminary results suggest that macrocyclic polymers outperform their linear analogs in terms of improving gene delivery efficiency,elevating blood circulation time,and enhancing colloidal stability of nanoparticles.
