The extraction of polyphenols from Aronia melanocarpa was carried out using a combination of enzymatic and ultrasound.After single-factor and orthogonal design and experiment,the optimized polyphenol extraction condit...The extraction of polyphenols from Aronia melanocarpa was carried out using a combination of enzymatic and ultrasound.After single-factor and orthogonal design and experiment,the optimized polyphenol extraction conditions were 1%enzyme,1:40 material-to-liquid ratio,55℃,60 min ultrasonication,70%ethanol,and the final extraction amount was 88.634 mg/g,which displayed a 25.15%and 34.08%improvement compared with the single ultrasonication and enzymatic extraction methods,respectively.Significant antibacterial effects of polyphenols were shown against Staphylococcus aureus,Escherichia coli and Bacillus subtilis.Further antioxidation effects were evaluated,and the superoxide anion radical scavenging rate,hydroxyl radical scavenging rate and DPPH free radical scavenging rate reached 45.2%,83.5%and 85.4%,respectively.This combined enzymatic and ultrasonic extraction method exhibited the advantages of high extraction rate,saving solvent consumption and extraction time,but also provided a new method for the development and utilization of natural antimicrobial and antioxidant health products.展开更多
The chlorinated and fluorinated zeolite catalysts were prepared by the impregnation of zeolites( H-ZSM-5,H-MOR or H-Y) using two halogen precursors( ammonium chloride and ammonium fluoride) in this study. The influenc...The chlorinated and fluorinated zeolite catalysts were prepared by the impregnation of zeolites( H-ZSM-5,H-MOR or H-Y) using two halogen precursors( ammonium chloride and ammonium fluoride) in this study. The influence of ultrasonic irradiation was evaluated for optimizing both halogen precursors for production of dimethylether( DME) via methanol dehydration in a fixed bed reactor. The catalysts were characterized by SEM,XRD,BET and NH3-TPD. The reaction conditions were temperatures from 100 to 300 ℃ and a WHSV = 15. 9 h-1. All halogenated catalysts showhigher catalytic activities at all reaction temperatures studied. However, the halogenated zeolite catalysts prepared under ultrasonic irradiation showhigher performance for DME formation. The chlorinated zeolite catalysts show higher activity and selectivity for DME production than the respective fluorinated versions.展开更多
A thin film TiO2 in hierarchical nano-structure with high photocatalytic activities was synthesized in simple steps with ultrasonication. The crystal structure and morphology of the photocatalyst were investigated by ...A thin film TiO2 in hierarchical nano-structure with high photocatalytic activities was synthesized in simple steps with ultrasonication. The crystal structure and morphology of the photocatalyst were investigated by X-ray diffraction (XRD) and high-resolution field emission scanning electron microscope (FE-SEM). In the present work, nanostructured TiO2 was directly formed onto a Ti substrate via a solution approach. This nanostructured TiO2 photocatalyst can be reused and will not generate secondary contamination to treated water. The photocatalytic activity of the synthesized TiO2 photocatalyst was evaluated by the degradation of phenol under UVC irradiation in water and was compared with the general sol-gel derived TiO2 films as well as a commercial DP-25 TiO2 coating. It was found that the synthesized nanostructured TiO2has significantly high and stable photocatalytic activity.展开更多
Peat and peatified wood are significant carbohydrate resources in tropical rainforests. The carbohydrates of cellulose and hemicellulose are important sources of monosaccharides for both vital activities and industria...Peat and peatified wood are significant carbohydrate resources in tropical rainforests. The carbohydrates of cellulose and hemicellulose are important sources of monosaccharides for both vital activities and industrial applications, such as furan production of furfural and hydroxymethyl furfural. Hydrothermal treatment at 200°C and ultrasonic irradiation pretreatment were used to recover monosaccharides from the abovementioned resources. The monosaccharide recovery from peat was shown to be higher than that from peatified wood. The conversion to organic acids is considered to proceed rapidly because acids are always detected with monosaccharides. This conversion is outstripped by the organic acid-to-gas reaction for treatment times longer than 20 min. The monosaccharide recovery from peatified wood was improved by the ultrasonication pretreatment. It is considered that ultrasonic irradiation broke down lignin blockages, enabling water molecules to access the carbohydrates more easily in the subsequent hydrothermal treatment.展开更多
We investigated the feasibility of sonodynamic therapy for glioma by low frequency ultrasoundwith5-aminolevulinic acid (5-ALA), a precursor of protoporphyrin IX (PpIX) in heme synthetic process. In vivo tumor model wa...We investigated the feasibility of sonodynamic therapy for glioma by low frequency ultrasoundwith5-aminolevulinic acid (5-ALA), a precursor of protoporphyrin IX (PpIX) in heme synthetic process. In vivo tumor model was made by inoculating human glioma cell line U87-MG subcutaneously in nude mice. The tumor was sonicated by 25-kHz ultrasound 4 hours following administration of 5-ALA. The tumor size decreased in 5-ALA administered (ALA(+)US(+)) mice, while increased in non-5-ALA administrated (ALA(-)US(+)) mice and non-sonicated mice (ALA(+)US(-)). The immunohistochemical analysis revealed an apoptotic change in tumor tissue of ALA(+)US(+) mice. The results showed the therapeutic effect of 25 kHz ultrasound for the glioma in 5-ALA administered tumor-bearing mice by inducing apoptotic change of tumor cells. This is a first report to elucidate the feasibility of therapeutic use of 25 kHz, relatively low frequency, ultrasound in sonodynamic therapy using 5-ALA as a sonosensitizer precursor. The utilization of this frequency will contribute to the development of sonodynamic therapy for gliomas and the spread of this technique in many hospitals that possess ultrasonic aspirators.展开更多
The effects of electric field and ultrasonication on the deposition and alignment of single-walled carbon nanotubes (SWCNTs) across a 10 μm electrode gap have been studied. It was found that a frequency of ~1 MHz of ...The effects of electric field and ultrasonication on the deposition and alignment of single-walled carbon nanotubes (SWCNTs) across a 10 μm electrode gap have been studied. It was found that a frequency of ~1 MHz of the applied field yields the largest current independent of the magnitude of the voltage or the ultrasonication time of the sample. Increasing the ultrasonication time of a SWCNT solution changes the I-V characteristics of the deposited nanotubes from linear to nonlinear for all the voltages and frequencies of the applied field. Even in the absence of an electric field, SWCNTs bridged the electrode gap up to a critical sonication time which depends on the concentration of nanotubes in the solution.展开更多
A series of as-synthesized HZSM-5 zeolites with different Si/Al ratios(25,90,120,240 and 400)were post-treated by ultrasonication for an optimum time of 60 min.The morphology,acidity and textural properties of HZSM-5 ...A series of as-synthesized HZSM-5 zeolites with different Si/Al ratios(25,90,120,240 and 400)were post-treated by ultrasonication for an optimum time of 60 min.The morphology,acidity and textural properties of HZSM-5 were characterized with XRD,SEM,N_2 adsorption and NH3-TPD techniques.The catalytic performance was evaluated by dehydration of methanol to dimethyl ether(DME),which is a promising gaseous automotive fuel in future.It was found that the Si/Al ratio of HZSM-5 had considerable impacts on its catalytic performance for dehydration of methanol to DME.Its activity increased with decreasing Si/Al ratio from 400 to 25.Ultrasonication of HZSM-5 could significantly improve its catalytic performance.展开更多
The ultrasonic technique has been demonstrated to be a promising method for the disposal of hazardous oily sludge.However,the separation of oil from the surfaces of the solid particles is still difficult due to the st...The ultrasonic technique has been demonstrated to be a promising method for the disposal of hazardous oily sludge.However,the separation of oil from the surfaces of the solid particles is still difficult due to the strong interaction between the oil and solid particle.In this study,three types of surfactants were used to assist the ultrasonic treatment of oily sludge.The oil component,surface composition,and structure of the solid particle were determined.The results showed that different surfactants had different oil removal abilities.In the three surfactant-assisted sonication systems,the oil removal rate increased during the starting reaction period and then decreased with longer sonication time.The results of four components analysis suggested that surfactant easy to be ionized in water posed a better removal effect on resins,while the amphiphilic surfactant preferred saturates,aromatics and asphaltenes.The morphology analysis indicated that particle size was shattered into smaller ones by the ultrasonic process,and the wettability of the solid surface also changed during this treatment.The characterization of the oil component and solid particle during surfactant-assisted ultrasonication treatment will help to better understand the separation of oil from oily sludge and improve the oil recovery efficiency from oily sludge.展开更多
Under near ambient temperature and ultrasonication, nanocrystalline Zn(Oxin)2·2H2O (zinc 8-quinolinolate) was synthesized by solid state chemical reaction. The particle size distribution was relatively uniform, t...Under near ambient temperature and ultrasonication, nanocrystalline Zn(Oxin)2·2H2O (zinc 8-quinolinolate) was synthesized by solid state chemical reaction. The particle size distribution was relatively uniform, the morphology of the mare was ball like particle. The phase, particle size and morphology of the prepared nanocrystalline were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM) and electron diffraction (ED). The results show that the crystallite product has an average size of about 30 nm. The effects of a series of reaction conditions on the synthesis of Zn(Oxin)2·2H2O by solid state reaction were studied. During the synthesis of nanocrystalline Zn(Oxin)2·2H2O, the solid state reaction conditions such as changing reactant, matching proportion of reactant, adding inert substance, joining a little solvent or surface active solvent and grinding at different times may influence morphology, particle size and the size distribution of final products.展开更多
Multi-walled carbon nanotubes(MWCNTs) reinforced hollow glass microspheres(HGMs)/epoxy syntactic foam was fabricated. The effects of ultrasonication on the density, compression strength, and water absorption propertie...Multi-walled carbon nanotubes(MWCNTs) reinforced hollow glass microspheres(HGMs)/epoxy syntactic foam was fabricated. The effects of ultrasonication on the density, compression strength, and water absorption properties were studied. Better dispersed MWCNTs can be obtained after ultrasonication treatment, but an increasing viscosity will lead to a larger amount of voids during syntactic foam preparation especially when the content of HGMs is more than 70 vol%. The existing voids will decrease the density of epoxy syntactic foam. However, the ultrasonication does not change the compression strength much. Ultrasonication treatment will decrease the water absorption content due to the better dispersion and hydrophobic properties of MWCNTs. But a significant increase of water absorption content occurs when HGMs is more than 70 vol%, which is attributed to the higher viscosity and larger amount of voids.展开更多
Poly[2-methoxy-5-(2'-ethyl-hexyloxy)-1,4-phenylene vinylene](MEH-PPV)solutions with different concen-trations were prepared in chloroform for different ultrasonication times.The ultraviolet absorption and photolum...Poly[2-methoxy-5-(2'-ethyl-hexyloxy)-1,4-phenylene vinylene](MEH-PPV)solutions with different concen-trations were prepared in chloroform for different ultrasonication times.The ultraviolet absorption and photoluminescence(PL)spectra of the MEH-PPV solutions were measured,and the electronic states of the polymer chains under different experimental conditions were studied.The results showed that the effects of ultrasonication on the dilute and concentrated solutions were different.After ultrasonication,the intensity of the absorption peak at 280 nm significantly decreased,relative to the absorption peak at 500 nm for both dilute and concentrated solutions,indicating that the proportion of the two excited states in the polymer chains had changed.For dilute MEH-PPV solutions,the blue-shifted absorption(at about 500 nm)and PL spectra show that ultrasonication also led to polymer chain degradation and thus shortened the effective conjugation length.For concentrated solutions,however,the peak positions of the absorption spectra remained unchanged.In addition,the effects of the solution temperatures on the optical spectra for the MEH-PPV solutions were also discussed.展开更多
To investigate the effect of clay concentration on the structures and properties of bisphenol-A epoxy/nanoclay composites, three composites with organoclay concentrations of 2.5wt%,5wt%,and 7.5wt% of the epoxy resin w...To investigate the effect of clay concentration on the structures and properties of bisphenol-A epoxy/nanoclay composites, three composites with organoclay concentrations of 2.5wt%,5wt%,and 7.5wt% of the epoxy resin were prepared by in-situ polym- erization under mechanical stirring followed by ultrasonic treatment.The clay aggregates on micro-scale indicate the absence of fully exfoliated nanocomposites.The layer space decreases with the increase of clay concentration,which suggests that the exfoliation would be constrained if more clay is added as the ultrasonic force is exerted.The thermal decomposition temperature remains almost unchanged with the increase of clay concentration.The glass transition temperature of the composites decreases slightly with the in- crease of clay concentration,whereas the storage modulus increases with the increase of clay concentration.展开更多
文摘The extraction of polyphenols from Aronia melanocarpa was carried out using a combination of enzymatic and ultrasound.After single-factor and orthogonal design and experiment,the optimized polyphenol extraction conditions were 1%enzyme,1:40 material-to-liquid ratio,55℃,60 min ultrasonication,70%ethanol,and the final extraction amount was 88.634 mg/g,which displayed a 25.15%and 34.08%improvement compared with the single ultrasonication and enzymatic extraction methods,respectively.Significant antibacterial effects of polyphenols were shown against Staphylococcus aureus,Escherichia coli and Bacillus subtilis.Further antioxidation effects were evaluated,and the superoxide anion radical scavenging rate,hydroxyl radical scavenging rate and DPPH free radical scavenging rate reached 45.2%,83.5%and 85.4%,respectively.This combined enzymatic and ultrasonic extraction method exhibited the advantages of high extraction rate,saving solvent consumption and extraction time,but also provided a new method for the development and utilization of natural antimicrobial and antioxidant health products.
文摘The chlorinated and fluorinated zeolite catalysts were prepared by the impregnation of zeolites( H-ZSM-5,H-MOR or H-Y) using two halogen precursors( ammonium chloride and ammonium fluoride) in this study. The influence of ultrasonic irradiation was evaluated for optimizing both halogen precursors for production of dimethylether( DME) via methanol dehydration in a fixed bed reactor. The catalysts were characterized by SEM,XRD,BET and NH3-TPD. The reaction conditions were temperatures from 100 to 300 ℃ and a WHSV = 15. 9 h-1. All halogenated catalysts showhigher catalytic activities at all reaction temperatures studied. However, the halogenated zeolite catalysts prepared under ultrasonic irradiation showhigher performance for DME formation. The chlorinated zeolite catalysts show higher activity and selectivity for DME production than the respective fluorinated versions.
文摘A thin film TiO2 in hierarchical nano-structure with high photocatalytic activities was synthesized in simple steps with ultrasonication. The crystal structure and morphology of the photocatalyst were investigated by X-ray diffraction (XRD) and high-resolution field emission scanning electron microscope (FE-SEM). In the present work, nanostructured TiO2 was directly formed onto a Ti substrate via a solution approach. This nanostructured TiO2 photocatalyst can be reused and will not generate secondary contamination to treated water. The photocatalytic activity of the synthesized TiO2 photocatalyst was evaluated by the degradation of phenol under UVC irradiation in water and was compared with the general sol-gel derived TiO2 films as well as a commercial DP-25 TiO2 coating. It was found that the synthesized nanostructured TiO2has significantly high and stable photocatalytic activity.
文摘Peat and peatified wood are significant carbohydrate resources in tropical rainforests. The carbohydrates of cellulose and hemicellulose are important sources of monosaccharides for both vital activities and industrial applications, such as furan production of furfural and hydroxymethyl furfural. Hydrothermal treatment at 200°C and ultrasonic irradiation pretreatment were used to recover monosaccharides from the abovementioned resources. The monosaccharide recovery from peat was shown to be higher than that from peatified wood. The conversion to organic acids is considered to proceed rapidly because acids are always detected with monosaccharides. This conversion is outstripped by the organic acid-to-gas reaction for treatment times longer than 20 min. The monosaccharide recovery from peatified wood was improved by the ultrasonication pretreatment. It is considered that ultrasonic irradiation broke down lignin blockages, enabling water molecules to access the carbohydrates more easily in the subsequent hydrothermal treatment.
文摘We investigated the feasibility of sonodynamic therapy for glioma by low frequency ultrasoundwith5-aminolevulinic acid (5-ALA), a precursor of protoporphyrin IX (PpIX) in heme synthetic process. In vivo tumor model was made by inoculating human glioma cell line U87-MG subcutaneously in nude mice. The tumor was sonicated by 25-kHz ultrasound 4 hours following administration of 5-ALA. The tumor size decreased in 5-ALA administered (ALA(+)US(+)) mice, while increased in non-5-ALA administrated (ALA(-)US(+)) mice and non-sonicated mice (ALA(+)US(-)). The immunohistochemical analysis revealed an apoptotic change in tumor tissue of ALA(+)US(+) mice. The results showed the therapeutic effect of 25 kHz ultrasound for the glioma in 5-ALA administered tumor-bearing mice by inducing apoptotic change of tumor cells. This is a first report to elucidate the feasibility of therapeutic use of 25 kHz, relatively low frequency, ultrasound in sonodynamic therapy using 5-ALA as a sonosensitizer precursor. The utilization of this frequency will contribute to the development of sonodynamic therapy for gliomas and the spread of this technique in many hospitals that possess ultrasonic aspirators.
文摘The effects of electric field and ultrasonication on the deposition and alignment of single-walled carbon nanotubes (SWCNTs) across a 10 μm electrode gap have been studied. It was found that a frequency of ~1 MHz of the applied field yields the largest current independent of the magnitude of the voltage or the ultrasonication time of the sample. Increasing the ultrasonication time of a SWCNT solution changes the I-V characteristics of the deposited nanotubes from linear to nonlinear for all the voltages and frequencies of the applied field. Even in the absence of an electric field, SWCNTs bridged the electrode gap up to a critical sonication time which depends on the concentration of nanotubes in the solution.
文摘A series of as-synthesized HZSM-5 zeolites with different Si/Al ratios(25,90,120,240 and 400)were post-treated by ultrasonication for an optimum time of 60 min.The morphology,acidity and textural properties of HZSM-5 were characterized with XRD,SEM,N_2 adsorption and NH3-TPD techniques.The catalytic performance was evaluated by dehydration of methanol to dimethyl ether(DME),which is a promising gaseous automotive fuel in future.It was found that the Si/Al ratio of HZSM-5 had considerable impacts on its catalytic performance for dehydration of methanol to DME.Its activity increased with decreasing Si/Al ratio from 400 to 25.Ultrasonication of HZSM-5 could significantly improve its catalytic performance.
基金financial support from the National Natural Science Foundation of China(Nos.41977142 and 41807133)the special fund of State Key Joint Laboratory of Environment Simulation and Pollution Control(No.18K05ESPCT)。
文摘The ultrasonic technique has been demonstrated to be a promising method for the disposal of hazardous oily sludge.However,the separation of oil from the surfaces of the solid particles is still difficult due to the strong interaction between the oil and solid particle.In this study,three types of surfactants were used to assist the ultrasonic treatment of oily sludge.The oil component,surface composition,and structure of the solid particle were determined.The results showed that different surfactants had different oil removal abilities.In the three surfactant-assisted sonication systems,the oil removal rate increased during the starting reaction period and then decreased with longer sonication time.The results of four components analysis suggested that surfactant easy to be ionized in water posed a better removal effect on resins,while the amphiphilic surfactant preferred saturates,aromatics and asphaltenes.The morphology analysis indicated that particle size was shattered into smaller ones by the ultrasonic process,and the wettability of the solid surface also changed during this treatment.The characterization of the oil component and solid particle during surfactant-assisted ultrasonication treatment will help to better understand the separation of oil from oily sludge and improve the oil recovery efficiency from oily sludge.
基金Project (29631040) supported by the National Natural Science Foundation of China Project (200604) supported by the Scientific Research Foundation of Neijiang Teachers College, China
文摘Under near ambient temperature and ultrasonication, nanocrystalline Zn(Oxin)2·2H2O (zinc 8-quinolinolate) was synthesized by solid state chemical reaction. The particle size distribution was relatively uniform, the morphology of the mare was ball like particle. The phase, particle size and morphology of the prepared nanocrystalline were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM) and electron diffraction (ED). The results show that the crystallite product has an average size of about 30 nm. The effects of a series of reaction conditions on the synthesis of Zn(Oxin)2·2H2O by solid state reaction were studied. During the synthesis of nanocrystalline Zn(Oxin)2·2H2O, the solid state reaction conditions such as changing reactant, matching proportion of reactant, adding inert substance, joining a little solvent or surface active solvent and grinding at different times may influence morphology, particle size and the size distribution of final products.
基金Funded by the National Natural Science Foundation of China(Nos.51301029 and 51375071)the Fundamental Research Funds for the Central Universities(No.DUT17RC(3)012)
文摘Multi-walled carbon nanotubes(MWCNTs) reinforced hollow glass microspheres(HGMs)/epoxy syntactic foam was fabricated. The effects of ultrasonication on the density, compression strength, and water absorption properties were studied. Better dispersed MWCNTs can be obtained after ultrasonication treatment, but an increasing viscosity will lead to a larger amount of voids during syntactic foam preparation especially when the content of HGMs is more than 70 vol%. The existing voids will decrease the density of epoxy syntactic foam. However, the ultrasonication does not change the compression strength much. Ultrasonication treatment will decrease the water absorption content due to the better dispersion and hydrophobic properties of MWCNTs. But a significant increase of water absorption content occurs when HGMs is more than 70 vol%, which is attributed to the higher viscosity and larger amount of voids.
基金the Shanghai Leading Academic Discipline Project(No.B113)the Program for New Century ExcellentTalents(NCET)in University of China(No.NCET-04-0355).
文摘Poly[2-methoxy-5-(2'-ethyl-hexyloxy)-1,4-phenylene vinylene](MEH-PPV)solutions with different concen-trations were prepared in chloroform for different ultrasonication times.The ultraviolet absorption and photoluminescence(PL)spectra of the MEH-PPV solutions were measured,and the electronic states of the polymer chains under different experimental conditions were studied.The results showed that the effects of ultrasonication on the dilute and concentrated solutions were different.After ultrasonication,the intensity of the absorption peak at 280 nm significantly decreased,relative to the absorption peak at 500 nm for both dilute and concentrated solutions,indicating that the proportion of the two excited states in the polymer chains had changed.For dilute MEH-PPV solutions,the blue-shifted absorption(at about 500 nm)and PL spectra show that ultrasonication also led to polymer chain degradation and thus shortened the effective conjugation length.For concentrated solutions,however,the peak positions of the absorption spectra remained unchanged.In addition,the effects of the solution temperatures on the optical spectra for the MEH-PPV solutions were also discussed.
文摘To investigate the effect of clay concentration on the structures and properties of bisphenol-A epoxy/nanoclay composites, three composites with organoclay concentrations of 2.5wt%,5wt%,and 7.5wt% of the epoxy resin were prepared by in-situ polym- erization under mechanical stirring followed by ultrasonic treatment.The clay aggregates on micro-scale indicate the absence of fully exfoliated nanocomposites.The layer space decreases with the increase of clay concentration,which suggests that the exfoliation would be constrained if more clay is added as the ultrasonic force is exerted.The thermal decomposition temperature remains almost unchanged with the increase of clay concentration.The glass transition temperature of the composites decreases slightly with the in- crease of clay concentration,whereas the storage modulus increases with the increase of clay concentration.
