Flexible PANI-Polyethersulfone (PES) fibers were fabricated using the wet-spinning technique.PANI particles were uniformly distributed within the matrix and micropores formed by the phase separation of PES,which preve...Flexible PANI-Polyethersulfone (PES) fibers were fabricated using the wet-spinning technique.PANI particles were uniformly distributed within the matrix and micropores formed by the phase separation of PES,which prevented PANI particles aggregation and facilitated the formation of continuous ion transport channels.The experimental results reveals that the electrochemical performance of the fiber electrode material is optimal when the concentration of PES in the spinning solution is 15wt%.The assembled supercapacitor exhibits a commendable specific area capacitance of 162.75 mF·cm^(-2) at a current density of 0.5 mA·cm^(-2) and achieves an energy density of 14.47 mWh·cm^(-2) at a power density of 321.69 mW·cm^(-2).The capacitor retains 98.1% of its capacitance after 1 000 bending cycles.Therefore,the prepared fibers have good electrochemical properties and flexibility,and this simple and efficient preparation method is promising for the scalable production of flexible electrodes.展开更多
Graphene fiber-based supercapacitors hold great promise as flexible energy-storage devices. However, simultaneously achieving high ion-transport ability in electrode and electrolyte layer, which is crucial for realizi...Graphene fiber-based supercapacitors hold great promise as flexible energy-storage devices. However, simultaneously achieving high ion-transport ability in electrode and electrolyte layer, which is crucial for realizing the high electrochemical performance, still remains challenging. Here, a facile and effective strategy to solve the problem was proposed by developing a twisting-structured graphene/carbon nanotube(CNT) fiber supercapacitor via one-step wet-spinning process with customized multi-channel spinneret.The remarkable structure features of the resulting fiber supercapacitor with wrinkled and thin electrolyte layer, and well-developed porosity of fiber electrode favored the rapid infiltration and transport of electrolyte ions inside the electrode, as well as between electrode and electrolyte, thus boosting high specific capacitance of 187.6 mF cm^(-2) and energy density of 30.2 μWh cm^(-2), and featuring long cycling life(93%capacitance retention after 10,000 cycles) and excellent flexibility. Moreover, the specific capacitance and energy density could be further improved to 267.2 m F cm^(-2) and 66.8 μWh cm^(-2), respectively, when Mn O2 was incorporated into the fiber.展开更多
The evolvement of microstructure and properties of nascent fibers during coagulation process in the polyacrylonitrile （PAN） wet-spinning and the effect of coagulation bath conditions on the structure and properties ...The evolvement of microstructure and properties of nascent fibers during coagulation process in the polyacrylonitrile （PAN） wet-spinning and the effect of coagulation bath conditions on the structure and properties of the nascent fibers were investigated by the means of X-ray diffraction （XRD）, scanning electron microscope （SEM）, fiber fineness machine, fiber tensile strength machine, etc. The experimental results indicate that the nascent fibers become denser and have fewer inner defects, the diameter of nascent fibers shrink and the crystallization degree of nascent fibers gradually increases with the increasing of coagulation time. Too large spinning tension leads to grooves occurring on surface of fibers. To obtain circular cross-section of nascent fibers the optimal coagulation conditions are 50 ℃, 65% （concentration） and 0.9 （draw ratio）.展开更多
Spider silk is capturing the attention of scientists for its mechanical properties,biocompatibility,and biodegradability.Spiders can produce six types of silks,as well as special glue,which are used for survival and r...Spider silk is capturing the attention of scientists for its mechanical properties,biocompatibility,and biodegradability.Spiders can produce six types of silks,as well as special glue,which are used for survival and reproduction.During the last years of research,scientists deciphered gene sequences and expressed the most common types of spider silks.However,matching the mechanical properties of recombinant spider silks to native ones is still a big challenge.Moreover,in-depth studies are mostly focused on natural and recombinant ampullate silks,and only a few studies showed achievements on pyriform spidroin(PySp).In this study,repeatable parts of PySp were expressed,purified,and spun into fibers.Recombinase cloning strategy allowed to create highly-repetitive region parts clones efficiently in comparison to the traditional restriction enzyme cloning technique.A cost-effective high-yield purification strategy was used.This study provides strategies that can help to design recombinant spider silks with the same mechanical properties as native spider silks.展开更多
Nacre is a lightweight, strong, stiff, and tough material, which makes it a mimicking object for material design. Many attempts to mimic nacre by various methods resulted in the synthesis of artificial nacre with exce...Nacre is a lightweight, strong, stiff, and tough material, which makes it a mimicking object for material design. Many attempts to mimic nacre by various methods resulted in the synthesis of artificial nacre with excellent properties. However, the fabrication procedure was very laborious and time-consuming due to the sequential steps, and only limited-sized materials could be obtained. Hence, a novel design enabling scalable production of high-performance artificial nacre with uniform layered structures is urgently needed. We developed a novel wet-spinning assembly technique to rapidly manufacture continuous nacre- mimic graphene oxide （GO, brick）-sodium alginate （SA, mortar） films and fibers with excellent mechanical properties. At high concentrations, the GO-SA mixtures spontaneously produced liquid crystals （LCs） due to the template effect of GO, and continuous, 6 m long nacre-like GO-SA films were wet-spun from the obtained GO-SA liquid crystalline （LC） dope with a speed of up to 1.5 m/min. The assembled macroscopic GO-SA composites inherited the alignment of the GO sheets from the LC phase, and their mechanical properties were investigated by a joint experimental-computational study. The tensile tests revealed that the maximum strength （0） and Young＇s modulus （E） of the obtained films reached 239.6 MPa and 22.4 GPa, while the maximum values of o and E for the fibers were 784.9 MPa and 58 GPa, respectively. The described wet-spinning assembly method is applicable for a large-scale and fast production of high-performance continuous artificial nacre.展开更多
Ca（II） ions are added in the spinning dope to adjust the solidification rate of regenerated silk fibroin （RSF） solution during the wet-spinning process since Ca（II） ions are proved to be favorable to maintain th...Ca（II） ions are added in the spinning dope to adjust the solidification rate of regenerated silk fibroin （RSF） solution during the wet-spinning process since Ca（II） ions are proved to be favorable to maintain the stable silk fibroin network in our previous work. The results show that when Ca（II）/RSF ratios are 1/50 and 1/20, the resulted RSF fibers exhibit good performance with the breaking energy more than 70 kJ/kg. However, higher Ca（II）/RSF ratio （for example, 1/10） hinders the solidification of spinning dope and results in poor RSF fibers. These observations together with earlier papers from this laboratory confirm that to produce tough silk fibers the spinning conditions must allow sufficient time for the adjustment of silk fibroin molecular chains.展开更多
Native tissue is naturally comprised of highly-ordered cell-matrix assemblies in a multi-hierarchical way,and the nano/submicron alignment of fibrous matrix is found to be significant in supporting cellular functional...Native tissue is naturally comprised of highly-ordered cell-matrix assemblies in a multi-hierarchical way,and the nano/submicron alignment of fibrous matrix is found to be significant in supporting cellular functionalization.In this study,a self-designed wet-spinning device appended with a rotary receiving pool was used to continuously produce shear-patterned hydrogel microfibers with aligned submicron topography.The process that the flow-induced shear force reshapes the surface of hydrogel fiber into aligned submicron topography was systematically analysed.Afterwards,the effect of fiber topography on cellular longitudinal spread and elongation was investigated by culturing rat neuron-like PC12 cells and human osteosarcoma MG63 cells with the spun hydrogel microfibers,respectively.The results suggested that the stronger shear flow force would lead to more distinct aligned submicron topography on fiber surface,which could induce cell orientation along with fiber axis and therefore form the cell-matrix dual-alignment.Finally,a multi-hierarchical tissue-like structure constructed by dual-oriented cell-matrix assemblies was fabricated based on this wet-spinning method.This work is believed to be a potentially novel biofabrication scheme for bottom-up constructing of engineered linear tissue,such as nerve bundle,cortical bone,muscle and hepatic cord.展开更多
Surgical suture is commonly used in clinic due to its action in accelerating the process of wound healing.However,difficultly handling in minimally invasive surgery and bacteria-induced infection usually limit its use...Surgical suture is commonly used in clinic due to its action in accelerating the process of wound healing.However,difficultly handling in minimally invasive surgery and bacteria-induced infection usually limit its use in a wide range of applications.Here,we report a facile scalable strategy to fabricate surgical sutures with shape memory function and antibacterial activity for wound healing.Specifically,a shape memory polyurethane(SMPU)with a transition temperature(Ttrans)at 41.3℃was synthesized by adjusting the mole ratio of the hard/soft segment,and then the shape memory surgical sutures containing polyhexamethylene biguanide hydrochloride(PHMB)as a model drug for antibacterial activity were fabricated by a facile scalable one-step wet-spinning approach,in which PHMB was directly dissolved in the coagulation bath that enable its loading into the sutures through the dual diffusion during the phase separation.The prepared sutures were characterized by their morphology,mechanical properties,shape memory,antibacterial activity,as well as biocompatibility before the wound healing capability was tested in a mouse skin suture-wound model.It was demonstrated that the optimized suture is capable of both shape memory function and antibacterial activity,and promote wound healing,suggesting that the facile scalable one-step wet-spinning strategy provides a promising tool to fabricate surgical sutures for wound healing.展开更多
Graphene fibers(GFs)are ideal electrodes for f ibrous supercapacitors because of their excellent mechanical and electrical properties.However,the actual specific s urface area(SSA)of GFs is low due to the restacking o...Graphene fibers(GFs)are ideal electrodes for f ibrous supercapacitors because of their excellent mechanical and electrical properties.However,the actual specific s urface area(SSA)of GFs is low due to the restacking of g raphene sheets,which limits the capacitance enhancement o f GFs.One of the effective ways to increase the SSA of GFs is to construct a porous fiber structure,but it disrupts t he conductive pathway and adversely affects the electrochemical(EC)performance of GFs.Therefore,a wet-spun porous GF electrode coated with polypyrrole(PPy)was reported in this paper.The resulting electrode exhibits an areal specific capacitance of 31.25 mF·cm^(-2)and a good c ycling stability with a capacitance retention rate of 95%after 5000 charge/discharge cycles.These indicate that porous structures and PPy coating can synergistically improve the EC performance of GFs.展开更多
Functionalized multi-walled carbon nanotubes( fMWNTs) were prepared with chitosan via controlled surface deposition and crosslinking process and scanning electron microscopy( SEM),Fourier translation infrared spectros...Functionalized multi-walled carbon nanotubes( fMWNTs) were prepared with chitosan via controlled surface deposition and crosslinking process and scanning electron microscopy( SEM),Fourier translation infrared spectroscopy( FT-IR) and Xray diffraction( XRD) are used to character properties. A novel high-density chitosan( HCS) was dissolved in f-MWNTs dispersed dilute acetic acid with a maximal concentration of 5. 8%. The hollow fibers can be made by extruding the solution into a dilute alkali solution through a wet-spinning process and the tensile properties of the materials were evaluated by universal tester. The surface property of fibers,pretreated by Helium( He) and the following grafted with gelatin was evaluated with X-ray photoelectron spectroscopy( XPS).As the hollow fibers were intended for neural tissue engineering,its suitability was evaluated in vitro using rat Schwann cells( RSC96) as model cells. The cells attachment,proliferation and morphology,were studied by various microscopic techniques. Based on the results,the gelatin grafted HCS / f-MWNTs hollow fibers could be used as a potential cell carrier in neural tissue engineering.展开更多
One-dimensional graphene fibers(GFs)possess excellent properties,including high electrical conductivity,good physical and chemical stability,high thermal conductivity,flexibility,etc.GFs are ideal electrode materials ...One-dimensional graphene fibers(GFs)possess excellent properties,including high electrical conductivity,good physical and chemical stability,high thermal conductivity,flexibility,etc.GFs are ideal electrode materials for fiber-shaped supercapacitors.However,due to the lack of an effective method to manufacture GFs with high specific capacitance,their low energy density hinders their practical application.Herein,we decorated wet-spun graphene oxide fibers(GOFs)by dip-coating them with graphene oxide(GO)solutions containing different contents of lignin to obtain a core-sheath lignin/GO composite fibers.After carbonization and activation,we successfully prepared lignin derived carbon/GF electrodes.The assembled fiber-shaped supercapacitors(FSSCs)exhibit a specific capacitance of 9.98 mF/cm^(2)and an energy density of 0.89μW·h/cm^(2),about 6 times of those of pure GFs(1.57 mF/cm^(2)and 0.14μW·h/cm^(2),respectively),long cycling life and cycling stability.This suggests that the introduction of lignin derived carbon into GFs can effectively increase the specific capacitance and the energy density of FSSCs.展开更多
The effects of coagulation conditions on tensile properties of the regenerated cellulose fibers prepared by wet-spinning from NaOH/thiourea/urea(8∶6.5∶8 by weight)aqueous solvent were investigated by tensile tester,...The effects of coagulation conditions on tensile properties of the regenerated cellulose fibers prepared by wet-spinning from NaOH/thiourea/urea(8∶6.5∶8 by weight)aqueous solvent were investigated by tensile tester,X-ray diffraction(XRD),and scanning electron microscope(SEM).The results show that the tensile properties of the as-spun fibers change with the coagualtion concentration,temperature,and time.When the spinning solution is coagulated in 10% H2SO4/12.5% Na2SO4 aqueous solution,the as-spun fibers have a typical structure of cellulose II,a circular cross-section,and homogeneous morphological structure.展开更多
The polymer blend technique is a novel method to produced carbon nanofibers. In this paper, we have prepared fine carbon fibers and porous carbon materials by this technique, and we will discuss the experiment results...The polymer blend technique is a novel method to produced carbon nanofibers. In this paper, we have prepared fine carbon fibers and porous carbon materials by this technique, and we will discuss the experiment results by means of SEM, TGA, Element Analysis, etc.展开更多
Given that conventional bulky electrochemical energy storage devices are too rigid and heavy to be considered wearable,developing fully integrated power systems is expected to accelerate the successful commercializati...Given that conventional bulky electrochemical energy storage devices are too rigid and heavy to be considered wearable,developing fully integrated power systems is expected to accelerate the successful commercialization of smart electronic textiles.Although great achievements have been made for fiber-shaped energy storage devices, there remain key challenges pertaining to their fabrication efficiency, scalability, and stability. Herein, a general and highly efficient method is developed to continuously fabricate supercapacitor fibers with lengths of kilometers at high production rate up to 118 m/h through a simple one-step wet spinning method.Beneficial from the designed unique two-circle-in-one-circle architecture, the resulting supercapacitor fibers demonstrated high electrochemical stability even after being bended for 1 × 10~5 cycles. As a demonstration, these continuous supercapacitor fibers were further woven into a flexible power scarf for large-scale applications in wearable electronics. This simple and scalable fabrication process combined with the unique structure provides a general and effective paradigm to design other fiber-shaped devices like sensors, batteries,and solar cells.展开更多
The Bombyx mori silk fbers are regarded as one of the most fascinating fexible materials in the twenty-frst century and have shown great potential in areas including fber sensors,fber actuators,optical fbers,energy ha...The Bombyx mori silk fbers are regarded as one of the most fascinating fexible materials in the twenty-frst century and have shown great potential in areas including fber sensors,fber actuators,optical fbers,energy harvester,etc.The regenerated silk fbroin(SF)molecules taken from B.mori cocoon fbers have been verifed to be capable of mesoscopically reconstructing during the SF molecules refolding process.The key concern of this review is to summarize recent engineering applying principles of meso reconstruction,meso hybridization and meso doping to synthesize artifcial regenerated SF fbers with enhanced or even novel functions,especially based on rerouting the refolding process of SF molecules via controlling nucleation pathway.In general,the knowledge of the meso reconstruction of silk fbre shed light on the design and fabrication of other ultra-performance SF materials from the crystallization and meso structural point of view.展开更多
High strength and high toughness are vital for fibers’engineering applications,but are hard to simultaneously achieve.Herein,we synthesize a carbon nanotube(CNT)-thermoplastic polyurethanes(TPU)fiber reinforced by an...High strength and high toughness are vital for fibers’engineering applications,but are hard to simultaneously achieve.Herein,we synthesize a carbon nanotube(CNT)-thermoplastic polyurethanes(TPU)fiber reinforced by an amorphous ZrO_(2)layer through the wet-spinning method.The amorphous ZrO_(2)layer is in-situ grown on the surface of CNT and the hybrid nanowires are orientedly aligned with TPU to form the ternary fiber.The fiber possesses an excellent combination of high strength(84.6 MPa)and toughness(126.7 MJ/m^(3)),which is outstanding when compared with previously reported CNT-TPU fibers.The pull-out of nanowires attributed to the oriented alignment structure and the enhanced interface and restriction of deformation obtained from the amorphous ZrO_(2)layer are considered as the primary strengthening and toughening mechanisms.We anticipate that our fiber synthesis strategy gives a new path to design strong and tough fibers.展开更多
We proposed a novel approach to prepare high-performance continuous regenerated keratin fibers with wool-like structure by using the cortical cells and linear keratin from wool waste as reinforcement and adhesive,resp...We proposed a novel approach to prepare high-performance continuous regenerated keratin fibers with wool-like structure by using the cortical cells and linear keratin from wool waste as reinforcement and adhesive,respectively.The spindle-shaped cortical cells were taken from wool waste based on the different responses of cortical cells and mesenchyme in wool to the treatments of H_(2)O_(2) oxidation and ultrasonication.The linear keratin was yielded through dissolving wool waste in the green solution consisting of starch derived dithiothreitol and protein denaturant sodium dodecyl sulfate.The recycled keratin fibers were produced by wet-spinning of the mixture solution comprising of cortical cells,linear keratin and toughener poly(ethylene glycol)diacrylate,and crosslinked by glutaraldehyde and 4,4′-methylenebis-(phenyl isocyanate).The cortical cells were aligned along the regenerated fibers axis and retained quite a fewα-helical crystals of the intermediate filaments,benefitting improvement of mechanical properties.Consequently,the valuable chemical compositions and hierarchical microstructures of wool were largely inherited.Their mechanical properties,thermal stability,dyeing property,moisture absorption capability,and antistatic resistance resembled those of wool.The regenerated fibers contained 93.3 wt.%components of wool,and the amount of synthetic chemicals in the regenerated fibers was controlled to as low as 6.7 wt.%.展开更多
基金Funded by the Hubei Integrative Technology and Innovation Center for Advanced Fiberous Materials Open Fund (No.XC202425)。
文摘Flexible PANI-Polyethersulfone (PES) fibers were fabricated using the wet-spinning technique.PANI particles were uniformly distributed within the matrix and micropores formed by the phase separation of PES,which prevented PANI particles aggregation and facilitated the formation of continuous ion transport channels.The experimental results reveals that the electrochemical performance of the fiber electrode material is optimal when the concentration of PES in the spinning solution is 15wt%.The assembled supercapacitor exhibits a commendable specific area capacitance of 162.75 mF·cm^(-2) at a current density of 0.5 mA·cm^(-2) and achieves an energy density of 14.47 mWh·cm^(-2) at a power density of 321.69 mW·cm^(-2).The capacitor retains 98.1% of its capacitance after 1 000 bending cycles.Therefore,the prepared fibers have good electrochemical properties and flexibility,and this simple and efficient preparation method is promising for the scalable production of flexible electrodes.
基金financial supports from the National Key Research and Development Program of China (2016YFA0203301)the National Natural Science Foundation of China (U1710122, 51862035, 21773293)+5 种基金the Program for Science & Technology Innovation Talents in the Universities of Henan Province (18HASTIT007)the Natural Science Foundation of Henan Provinceof China (182300410201, 182300410202)Jiangxi Double Thousand Talents Program (Y. Zhang, S2018LQCQ0016)the Science and Technology Project of Jiangxi Province (20181ACH80008, 20181ACE50012)the Key Foundation of He’nan Educational Committee (18A150029)the Fundamental Research Funds for the Universities of Henan Province (NSFRF180337)。
文摘Graphene fiber-based supercapacitors hold great promise as flexible energy-storage devices. However, simultaneously achieving high ion-transport ability in electrode and electrolyte layer, which is crucial for realizing the high electrochemical performance, still remains challenging. Here, a facile and effective strategy to solve the problem was proposed by developing a twisting-structured graphene/carbon nanotube(CNT) fiber supercapacitor via one-step wet-spinning process with customized multi-channel spinneret.The remarkable structure features of the resulting fiber supercapacitor with wrinkled and thin electrolyte layer, and well-developed porosity of fiber electrode favored the rapid infiltration and transport of electrolyte ions inside the electrode, as well as between electrode and electrolyte, thus boosting high specific capacitance of 187.6 mF cm^(-2) and energy density of 30.2 μWh cm^(-2), and featuring long cycling life(93%capacitance retention after 10,000 cycles) and excellent flexibility. Moreover, the specific capacitance and energy density could be further improved to 267.2 m F cm^(-2) and 66.8 μWh cm^(-2), respectively, when Mn O2 was incorporated into the fiber.
基金Funded by the Science and Technology Program of the Higher Education Institutions of Shandong Province (No. J09LD06)the Doctoral Fund of University of Jinan (No. XBS0813)
文摘The evolvement of microstructure and properties of nascent fibers during coagulation process in the polyacrylonitrile （PAN） wet-spinning and the effect of coagulation bath conditions on the structure and properties of the nascent fibers were investigated by the means of X-ray diffraction （XRD）, scanning electron microscope （SEM）, fiber fineness machine, fiber tensile strength machine, etc. The experimental results indicate that the nascent fibers become denser and have fewer inner defects, the diameter of nascent fibers shrink and the crystallization degree of nascent fibers gradually increases with the increasing of coagulation time. Too large spinning tension leads to grooves occurring on surface of fibers. To obtain circular cross-section of nascent fibers the optimal coagulation conditions are 50 ℃, 65% （concentration） and 0.9 （draw ratio）.
基金National Natural Science Foundation of China(No.31470836)Science and Technology Commission of Shanghai Municipality,China(No.19ZR1471000)。
文摘Spider silk is capturing the attention of scientists for its mechanical properties,biocompatibility,and biodegradability.Spiders can produce six types of silks,as well as special glue,which are used for survival and reproduction.During the last years of research,scientists deciphered gene sequences and expressed the most common types of spider silks.However,matching the mechanical properties of recombinant spider silks to native ones is still a big challenge.Moreover,in-depth studies are mostly focused on natural and recombinant ampullate silks,and only a few studies showed achievements on pyriform spidroin(PySp).In this study,repeatable parts of PySp were expressed,purified,and spun into fibers.Recombinase cloning strategy allowed to create highly-repetitive region parts clones efficiently in comparison to the traditional restriction enzyme cloning technique.A cost-effective high-yield purification strategy was used.This study provides strategies that can help to design recombinant spider silks with the same mechanical properties as native spider silks.
基金This research was financially supported by The National Natural Science Foundation of China （Nos. 21325417, 51173162 and 51533008） and State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University （No. LK1403）.
文摘Nacre is a lightweight, strong, stiff, and tough material, which makes it a mimicking object for material design. Many attempts to mimic nacre by various methods resulted in the synthesis of artificial nacre with excellent properties. However, the fabrication procedure was very laborious and time-consuming due to the sequential steps, and only limited-sized materials could be obtained. Hence, a novel design enabling scalable production of high-performance artificial nacre with uniform layered structures is urgently needed. We developed a novel wet-spinning assembly technique to rapidly manufacture continuous nacre- mimic graphene oxide （GO, brick）-sodium alginate （SA, mortar） films and fibers with excellent mechanical properties. At high concentrations, the GO-SA mixtures spontaneously produced liquid crystals （LCs） due to the template effect of GO, and continuous, 6 m long nacre-like GO-SA films were wet-spun from the obtained GO-SA liquid crystalline （LC） dope with a speed of up to 1.5 m/min. The assembled macroscopic GO-SA composites inherited the alignment of the GO sheets from the LC phase, and their mechanical properties were investigated by a joint experimental-computational study. The tensile tests revealed that the maximum strength （0） and Young＇s modulus （E） of the obtained films reached 239.6 MPa and 22.4 GPa, while the maximum values of o and E for the fibers were 784.9 MPa and 58 GPa, respectively. The described wet-spinning assembly method is applicable for a large-scale and fast production of high-performance continuous artificial nacre.
基金supported by the National Natural Science Foundation of China(Nos.10979022,20974025 and 21034003)the National High Technology Research and Development Program of China(863 Program)(No.2012AA030309)
文摘Ca（II） ions are added in the spinning dope to adjust the solidification rate of regenerated silk fibroin （RSF） solution during the wet-spinning process since Ca（II） ions are proved to be favorable to maintain the stable silk fibroin network in our previous work. The results show that when Ca（II）/RSF ratios are 1/50 and 1/20, the resulted RSF fibers exhibit good performance with the breaking energy more than 70 kJ/kg. However, higher Ca（II）/RSF ratio （for example, 1/10） hinders the solidification of spinning dope and results in poor RSF fibers. These observations together with earlier papers from this laboratory confirm that to produce tough silk fibers the spinning conditions must allow sufficient time for the adjustment of silk fibroin molecular chains.
基金This work is supported by the National Natural Science Foundation of China(Contract Grant No.51473098,and 51673128).
文摘Native tissue is naturally comprised of highly-ordered cell-matrix assemblies in a multi-hierarchical way,and the nano/submicron alignment of fibrous matrix is found to be significant in supporting cellular functionalization.In this study,a self-designed wet-spinning device appended with a rotary receiving pool was used to continuously produce shear-patterned hydrogel microfibers with aligned submicron topography.The process that the flow-induced shear force reshapes the surface of hydrogel fiber into aligned submicron topography was systematically analysed.Afterwards,the effect of fiber topography on cellular longitudinal spread and elongation was investigated by culturing rat neuron-like PC12 cells and human osteosarcoma MG63 cells with the spun hydrogel microfibers,respectively.The results suggested that the stronger shear flow force would lead to more distinct aligned submicron topography on fiber surface,which could induce cell orientation along with fiber axis and therefore form the cell-matrix dual-alignment.Finally,a multi-hierarchical tissue-like structure constructed by dual-oriented cell-matrix assemblies was fabricated based on this wet-spinning method.This work is believed to be a potentially novel biofabrication scheme for bottom-up constructing of engineered linear tissue,such as nerve bundle,cortical bone,muscle and hepatic cord.
基金sponsored by the National Natural Science Foundation of China(No.51803128)Opening Project of Key Laboratory of Leather Chemistry and Engineering(Sichuan University),Ministry of Education(No.20826041C4159)+1 种基金Sichuan Science and Technology Programs(Nos.2017SZYZF00009,19YJ0126)trategic Project of Lu Zhou Science&Technology Bureau(No.2017CDLZ-S01)。
文摘Surgical suture is commonly used in clinic due to its action in accelerating the process of wound healing.However,difficultly handling in minimally invasive surgery and bacteria-induced infection usually limit its use in a wide range of applications.Here,we report a facile scalable strategy to fabricate surgical sutures with shape memory function and antibacterial activity for wound healing.Specifically,a shape memory polyurethane(SMPU)with a transition temperature(Ttrans)at 41.3℃was synthesized by adjusting the mole ratio of the hard/soft segment,and then the shape memory surgical sutures containing polyhexamethylene biguanide hydrochloride(PHMB)as a model drug for antibacterial activity were fabricated by a facile scalable one-step wet-spinning approach,in which PHMB was directly dissolved in the coagulation bath that enable its loading into the sutures through the dual diffusion during the phase separation.The prepared sutures were characterized by their morphology,mechanical properties,shape memory,antibacterial activity,as well as biocompatibility before the wound healing capability was tested in a mouse skin suture-wound model.It was demonstrated that the optimized suture is capable of both shape memory function and antibacterial activity,and promote wound healing,suggesting that the facile scalable one-step wet-spinning strategy provides a promising tool to fabricate surgical sutures for wound healing.
基金National Natural Science Foundation of China(No.51903033)Shanghai Sailing Program,China(No.19YF1400800)。
文摘Graphene fibers(GFs)are ideal electrodes for f ibrous supercapacitors because of their excellent mechanical and electrical properties.However,the actual specific s urface area(SSA)of GFs is low due to the restacking of g raphene sheets,which limits the capacitance enhancement o f GFs.One of the effective ways to increase the SSA of GFs is to construct a porous fiber structure,but it disrupts t he conductive pathway and adversely affects the electrochemical(EC)performance of GFs.Therefore,a wet-spun porous GF electrode coated with polypyrrole(PPy)was reported in this paper.The resulting electrode exhibits an areal specific capacitance of 31.25 mF·cm^(-2)and a good c ycling stability with a capacitance retention rate of 95%after 5000 charge/discharge cycles.These indicate that porous structures and PPy coating can synergistically improve the EC performance of GFs.
基金State Key Laboratory for Modification of Chemical Fibers and Polymer Materials,China(No.LZ0902)Shanghai Science and Technical Committee,China(No.12DZ194030)
文摘Functionalized multi-walled carbon nanotubes( fMWNTs) were prepared with chitosan via controlled surface deposition and crosslinking process and scanning electron microscopy( SEM),Fourier translation infrared spectroscopy( FT-IR) and Xray diffraction( XRD) are used to character properties. A novel high-density chitosan( HCS) was dissolved in f-MWNTs dispersed dilute acetic acid with a maximal concentration of 5. 8%. The hollow fibers can be made by extruding the solution into a dilute alkali solution through a wet-spinning process and the tensile properties of the materials were evaluated by universal tester. The surface property of fibers,pretreated by Helium( He) and the following grafted with gelatin was evaluated with X-ray photoelectron spectroscopy( XPS).As the hollow fibers were intended for neural tissue engineering,its suitability was evaluated in vitro using rat Schwann cells( RSC96) as model cells. The cells attachment,proliferation and morphology,were studied by various microscopic techniques. Based on the results,the gelatin grafted HCS / f-MWNTs hollow fibers could be used as a potential cell carrier in neural tissue engineering.
基金National Natural Science Foundation of China(No.51903033)Fundamental Research Funds for the Central Universities,China(Nos.2232020G-01 and 20D110110)Shanghai Sailing Program,China(No.19YF1400800)。
文摘One-dimensional graphene fibers(GFs)possess excellent properties,including high electrical conductivity,good physical and chemical stability,high thermal conductivity,flexibility,etc.GFs are ideal electrode materials for fiber-shaped supercapacitors.However,due to the lack of an effective method to manufacture GFs with high specific capacitance,their low energy density hinders their practical application.Herein,we decorated wet-spun graphene oxide fibers(GOFs)by dip-coating them with graphene oxide(GO)solutions containing different contents of lignin to obtain a core-sheath lignin/GO composite fibers.After carbonization and activation,we successfully prepared lignin derived carbon/GF electrodes.The assembled fiber-shaped supercapacitors(FSSCs)exhibit a specific capacitance of 9.98 mF/cm^(2)and an energy density of 0.89μW·h/cm^(2),about 6 times of those of pure GFs(1.57 mF/cm^(2)and 0.14μW·h/cm^(2),respectively),long cycling life and cycling stability.This suggests that the introduction of lignin derived carbon into GFs can effectively increase the specific capacitance and the energy density of FSSCs.
文摘The effects of coagulation conditions on tensile properties of the regenerated cellulose fibers prepared by wet-spinning from NaOH/thiourea/urea(8∶6.5∶8 by weight)aqueous solvent were investigated by tensile tester,X-ray diffraction(XRD),and scanning electron microscope(SEM).The results show that the tensile properties of the as-spun fibers change with the coagualtion concentration,temperature,and time.When the spinning solution is coagulated in 10% H2SO4/12.5% Na2SO4 aqueous solution,the as-spun fibers have a typical structure of cellulose II,a circular cross-section,and homogeneous morphological structure.
基金China Postdoctoral Science Foundation (2005037463)
文摘The polymer blend technique is a novel method to produced carbon nanofibers. In this paper, we have prepared fine carbon fibers and porous carbon materials by this technique, and we will discuss the experiment results by means of SEM, TGA, Element Analysis, etc.
基金financially supported by the Ministry of Science and Technology (No. 2016YFA0203302)the National Natural Science Foundation of China (Nos. 21634003, 51573027, 51403038, 51673043, and 21604012)+1 种基金the Shanghai Science and Technology Committee (STCSM) (Nos. 16JC1400702, 15XD1500400, and 15JC1490200)the project funded by China Postdoctoral Science Foundation (No. KLH1615142)
文摘Given that conventional bulky electrochemical energy storage devices are too rigid and heavy to be considered wearable,developing fully integrated power systems is expected to accelerate the successful commercialization of smart electronic textiles.Although great achievements have been made for fiber-shaped energy storage devices, there remain key challenges pertaining to their fabrication efficiency, scalability, and stability. Herein, a general and highly efficient method is developed to continuously fabricate supercapacitor fibers with lengths of kilometers at high production rate up to 118 m/h through a simple one-step wet spinning method.Beneficial from the designed unique two-circle-in-one-circle architecture, the resulting supercapacitor fibers demonstrated high electrochemical stability even after being bended for 1 × 10~5 cycles. As a demonstration, these continuous supercapacitor fibers were further woven into a flexible power scarf for large-scale applications in wearable electronics. This simple and scalable fabrication process combined with the unique structure provides a general and effective paradigm to design other fiber-shaped devices like sensors, batteries,and solar cells.
基金This work was financially supported by the National Natural Science Foundation of China(Grant no.12074322)Science and Technology Project of Xiamen City(3502Z20183012)+1 种基金Science and Technology Planning Project of Guangdong Province(2018B030331001)Shenzhen Science and technology plan project(JCYJ20180504170208402).
文摘The Bombyx mori silk fbers are regarded as one of the most fascinating fexible materials in the twenty-frst century and have shown great potential in areas including fber sensors,fber actuators,optical fbers,energy harvester,etc.The regenerated silk fbroin(SF)molecules taken from B.mori cocoon fbers have been verifed to be capable of mesoscopically reconstructing during the SF molecules refolding process.The key concern of this review is to summarize recent engineering applying principles of meso reconstruction,meso hybridization and meso doping to synthesize artifcial regenerated SF fbers with enhanced or even novel functions,especially based on rerouting the refolding process of SF molecules via controlling nucleation pathway.In general,the knowledge of the meso reconstruction of silk fbre shed light on the design and fabrication of other ultra-performance SF materials from the crystallization and meso structural point of view.
基金This work was supported by the National Key R&D Program of China(Nos.2020YFA0710403,2020YFA0710404)the National Natural Science Foundation of China(Nos.52073008,U1910208).
文摘High strength and high toughness are vital for fibers’engineering applications,but are hard to simultaneously achieve.Herein,we synthesize a carbon nanotube(CNT)-thermoplastic polyurethanes(TPU)fiber reinforced by an amorphous ZrO_(2)layer through the wet-spinning method.The amorphous ZrO_(2)layer is in-situ grown on the surface of CNT and the hybrid nanowires are orientedly aligned with TPU to form the ternary fiber.The fiber possesses an excellent combination of high strength(84.6 MPa)and toughness(126.7 MJ/m^(3)),which is outstanding when compared with previously reported CNT-TPU fibers.The pull-out of nanowires attributed to the oriented alignment structure and the enhanced interface and restriction of deformation obtained from the amorphous ZrO_(2)layer are considered as the primary strengthening and toughening mechanisms.We anticipate that our fiber synthesis strategy gives a new path to design strong and tough fibers.
基金National Natural Science Foundation of China,Grant/Award Numbers:52033011,51773229,51873235,51973237Natural Science Foundation of Guangdong Province,Grant/Award Numbers:2019B1515120038,2021A1515010417,2020A1515011276+1 种基金Science and Technology Planning Project of Guangdong Province,Grant/Award Number:2020B010179001Industry-University-Research Collaboration Project of Zhuhai City,Grant/Award Number:ZH22017001200004PWC。
文摘We proposed a novel approach to prepare high-performance continuous regenerated keratin fibers with wool-like structure by using the cortical cells and linear keratin from wool waste as reinforcement and adhesive,respectively.The spindle-shaped cortical cells were taken from wool waste based on the different responses of cortical cells and mesenchyme in wool to the treatments of H_(2)O_(2) oxidation and ultrasonication.The linear keratin was yielded through dissolving wool waste in the green solution consisting of starch derived dithiothreitol and protein denaturant sodium dodecyl sulfate.The recycled keratin fibers were produced by wet-spinning of the mixture solution comprising of cortical cells,linear keratin and toughener poly(ethylene glycol)diacrylate,and crosslinked by glutaraldehyde and 4,4′-methylenebis-(phenyl isocyanate).The cortical cells were aligned along the regenerated fibers axis and retained quite a fewα-helical crystals of the intermediate filaments,benefitting improvement of mechanical properties.Consequently,the valuable chemical compositions and hierarchical microstructures of wool were largely inherited.Their mechanical properties,thermal stability,dyeing property,moisture absorption capability,and antistatic resistance resembled those of wool.The regenerated fibers contained 93.3 wt.%components of wool,and the amount of synthetic chemicals in the regenerated fibers was controlled to as low as 6.7 wt.%.
