Nano-ZrO2 and PEEK particles were synergistically filled in unfilled PTFE to improve the wear resistance and maintain a relatively low friction coefficient,and the materials were studied using a reciprocating sliding ...Nano-ZrO2 and PEEK particles were synergistically filled in unfilled PTFE to improve the wear resistance and maintain a relatively low friction coefficient,and the materials were studied using a reciprocating sliding friction and wear tester.In the friction tests,the evolution of various tribological characteristics in both the contact interfaces and debris was observed,and the wear mechanism of the PTFE composites was investigated.The results showed that the wear rate of the PTFE composites synergistically filled with nano-ZrO2 and PEEK was lower and its friction coefficient was slightly higher than that of the unfilled PTFE;the uniformity and continuity of the transfer film generated by the composite with nano-ZrO2 and PEEK were the best,and the particle size of the debris was minimal in comparison to that in other sample systems.展开更多
Polytetrafluoroethylene (PTFE) is a commonly used seal material for oil-free engine that is well known for its excellent tribological properties. In this work, the nano-ZrO2 particles were used as the friction modifie...Polytetrafluoroethylene (PTFE) is a commonly used seal material for oil-free engine that is well known for its excellent tribological properties. In this work, the nano-ZrO2 particles were used as the friction modifiers to improve the friction and wear performance of PTFE-PPS composites. The friction and wear characteristics of PTFE/PPS-nano-ZrO2 composites were investigated by a block-on-ring tester under dry friction sliding condition. The worn surfaces, counterpart transfer films and wear debris were studied by scanning electron microscopy and X-ray photoelectron spectroscopy. It was found that the increase of nano- ZrO2 content could effectively reduce the coefficient of friction and enhance the anti-wear ability of PTFEPPS composites. Especially, the best tribological properties of the composites were obtained when the particle content of nano-ZrO2 was 10 vol%, the anti-wear performance of composite is 195 times better than that of the unfilled PTFE-PPS composite. Under different conditions, the coefficient of friction of PTFE/PPS-nano-ZrO2 composites was more affected by the applied load while the wear rate was more affected by the sliding velocity.展开更多
The Al2O3-ZrO2（3Y）-SiC composite ceramics used in solar thermal power were prepared by micrometric Al2O3,nano-ZrO2 and SiC powders under the condition of pressureless sintering.The bulk density and bending strength ...The Al2O3-ZrO2（3Y）-SiC composite ceramics used in solar thermal power were prepared by micrometric Al2O3,nano-ZrO2 and SiC powders under the condition of pressureless sintering.The bulk density and bending strength of samples with 10vol% nano-ZrO2 sintered at 1480℃ were 3.222 g/cm3 and 160.4MPa,respectively.The bending strength of samples after 7 times thermal shock tests （quenching from 1000℃ to 25℃ in air medium） is 132.0MPa,loss rate of bending strength is only 17%.The effect of nano-ZrO2 content on the microstructure and performance of Al2O3-ZrO2（3Y）-SiC composite ceramic was investigated.The experimental results show that the bending strength of samples with above 10vol% nano-ZrO2 content has decreased,because the volume expansion resulting from t-ZrO2 to m-ZrO2 phase transformation is excessive;Adding proper nano-ZrO2 would be contributed to improve the thermal shock resistance of the composite ceramics.The Al2O3-ZrO2（3Y）-SiC composite ceramic has promising potential application in solar thermal power.展开更多
Recently, more and more interest has been focused on zirconia and its characteristics. In this paper, aluminum can be successfully incorporated into nano-ZrO2 via a cationic surfactant assisted route in the earlier pr...Recently, more and more interest has been focused on zirconia and its characteristics. In this paper, aluminum can be successfully incorporated into nano-ZrO2 via a cationic surfactant assisted route in the earlier preparation procedure. XRD, TEM, EDS, Uv-vis and N2 adsorption-desorption analysis methods were adopted for the characterization of prepared samples. The results show that aluminum has been homogeneously incorporated into nano-ZrO2. The prepared aluminum-doped samples show a distinctive blue shift in the Uv-vis spectra compared to normal nano-ZrO2. The distinctive increase of thermal stability and a mesoporous structure were observed.展开更多
Nano-ZrO2 particles were modified by poly(ethylene terephalate) prepolymer(pre-PET) via polycondensation.FT-IR,TEM,and TGA results showed that pre-PET was successfully grafted on the surface of nano-ZrO2particles.Comp...Nano-ZrO2 particles were modified by poly(ethylene terephalate) prepolymer(pre-PET) via polycondensation.FT-IR,TEM,and TGA results showed that pre-PET was successfully grafted on the surface of nano-ZrO2particles.Compared to the original nano-ZrO2,the grafted nano-ZrO2 had better compatibility with the polycarbonate(PC) matrix and could be dispersed more homogeneously in PC.Hence,interfacial adhesion between ZrO2 and PC was enhanced.The mechanical properties of the resultant PC/nano-ZrO2 composite like tensile strength and notched impact strength were greatly improved.Calculated respectively from tensile yield stress PC/nano-ZrO2 composites,the interfacial interaction parameter B was employed to quantitatively characterize the effective interfacial interaction between the nano-ZrO2 and PC matrix.展开更多
Catalyst plays an important role in the dehydration of N-（hydroxylethyl）pyrrolidone （NHP） to prepare N-vinyl-pyrrolidone （NVP）. At present, NVP yield is only about 30% on commercial ZrO2 catalyst. A coupled prec...Catalyst plays an important role in the dehydration of N-（hydroxylethyl）pyrrolidone （NHP） to prepare N-vinyl-pyrrolidone （NVP）. At present, NVP yield is only about 30% on commercial ZrO2 catalyst. A coupled precipitation and solid dispersion technique was designed to prepare the nano-ZrO2 catalyst, in which rare earth metal oxides （REOx） was used as electronic promoter. The results indicated that the catalyst doped REOx （S-1.0） exhibits the optimum performance of NHP dehydration at moderate conditions. NHP conversion and NVP selectivity are respectively 97.0%, 82.3%. Of special interest is that the indexes of the catalyst （S-1.0-1.0） are up to 98.4% and 89.2% respectively. Furthermore, this catalyst bears the good stability. It means that nano-ZrO2 doped REOx catalyst might be a potential commercial catalyst for the NHP dehydration.展开更多
Waterborne microbial contamination represents a significant global environmental challenge.Microorganisms can induce water pollution,precipitating infectious disease outbreaks and posing a substantial threat to human ...Waterborne microbial contamination represents a significant global environmental challenge.Microorganisms can induce water pollution,precipitating infectious disease outbreaks and posing a substantial threat to human health.Currently,the excessive use of conventional antibiotics has resulted in the emergence of bacterial resistance,posing a challenge to the design and development of antimicrobial agents with high antibacterial efficacy in diverse water such as rivers,lakes,and wastewater from microbiology laboratories.Bimetallic nanomaterials,that amalgamate the distinctive characteristics of diverse metals,are garnering attention due to their synergistic properties.In this study,PVP-FeMo_(2)S_(3)(PVP:Polyvinylpyrrolidone)and PVP-ZnMo_(2)S_(3)nanocrystals were synthesized by a high-temperature reaction.The prepared nanocrystals exhibited excellent biocompatibility,regular morphology,long-term stability,and remarkable antibacterial e ects.The bacterial biofilms could be eradicated by the combination of photothermal(PTT)and photodynamic synergistic e ects of PVP-FeMo_(2)S_(3)and PVP-ZnMo_(2)S_(3)nanocrystals.PVP-ZnMo_(2)S_(3)nanocrystals exhibited enhanced PTT conversion efficiency for water treatment.Remarkably,even after 20 cycles of recycling,PVP-ZnMo_(2)S_(3)retained substantial antibacterial e cacy.The excellent biosafety of PVP-ZnMo_(2)S_(3)further guarantees the safety of water quality post-treatment.Thus,PVP-ZnMo_(2)S_(3)bimetallic nanocrystals can serve as a novel antimicrobial agent for the treatment of microbial contamination in water.This study offers a potential strategy to mitigate secondary water pollution and prevent the development of drug resistance among pathogenic microorganisms.展开更多
Cyprinid herpesvirus 2(CyHV-2),a member of the Alloherpesviridae family belonging to the genus Cyprinivirus,was initially isolated from goldfish(Carassius auratus)and has been recently emerging as a virulent pathogen ...Cyprinid herpesvirus 2(CyHV-2),a member of the Alloherpesviridae family belonging to the genus Cyprinivirus,was initially isolated from goldfish(Carassius auratus)and has been recently emerging as a virulent pathogen for cultured prussian carp(Carassius auratus gibelio)world-wide.In this study,a novel and effective method for concentration and quantification of live CyHV-2 virions from water was successfully established through coupling the iron flocculation with real time qPCR assay.Then,the shedding intensity of CyHV-2 in fish-tank water from artificially-challenged goldfish(25 fish/20 L)was monitored continuously for 7 days on a daily basis through quantitating viral genomic copy numbers by qPCR,and the maximum shedding level was determined to be 105 copies/L.Horizontal transmission research system was established by inoculating healthy goldfish in water spiked with serial dilution of CyHV-2 virions ranging from 107 to 103 copies/L.Our results indicated that water-borne CyHV-2 efficiently caused the infection of tested goldfish even in a concentration of 103 copies/L,and the overall transmission efficacy was not linearly correlated with the level of input virus in the fish tank.Commercial disinfectant Composite Sodium Chlorite Powder(CSCP)has been widely applied in aquaculture to control microbial infection through direct spill in the water,and its effect in inactivating the CyHV-2 infectivity remains unknown.We further determined that the EC50 of CSCP against 3.89 TCID50/mL CyHV-2 was close to 15.625μg/mL in vitro,and application of CSCP in a level as high as 60μg/mL(the safety concentration of CSCP for goldfish)couldn’t protect goldfish from CyHV-2 challenge through immersion.Thus,the disinfectant CSCP was regarded as none-effective for blocking CyHV-2 transmission in water during epidemic.Overall,our data provided quantitative data to demonstrate the shedding intensity of CyHV-2 in water,and CSCP was shown to be not effective in blocking water-borne horizontal transmission of CyHV-2 in goldfish.The virus-concentration protocol and virus-inhibition assay established here also paved the way for evaluating more commercial disinfectants in their effects in blocking water-borne horizontal transmission of CyHV-2.展开更多
基金Supported by the National Natural Science Foundation of China(No.51165022)Lanzhou Science and Technology Bureau Foundation(No.20122117)the Natural Science Foundation of Gansu Province(No.1310RJZA036).
文摘Nano-ZrO2 and PEEK particles were synergistically filled in unfilled PTFE to improve the wear resistance and maintain a relatively low friction coefficient,and the materials were studied using a reciprocating sliding friction and wear tester.In the friction tests,the evolution of various tribological characteristics in both the contact interfaces and debris was observed,and the wear mechanism of the PTFE composites was investigated.The results showed that the wear rate of the PTFE composites synergistically filled with nano-ZrO2 and PEEK was lower and its friction coefficient was slightly higher than that of the unfilled PTFE;the uniformity and continuity of the transfer film generated by the composite with nano-ZrO2 and PEEK were the best,and the particle size of the debris was minimal in comparison to that in other sample systems.
基金Funded by the National Natural Science Foundation of China(Nos.51165022,51675509)
文摘Polytetrafluoroethylene (PTFE) is a commonly used seal material for oil-free engine that is well known for its excellent tribological properties. In this work, the nano-ZrO2 particles were used as the friction modifiers to improve the friction and wear performance of PTFE-PPS composites. The friction and wear characteristics of PTFE/PPS-nano-ZrO2 composites were investigated by a block-on-ring tester under dry friction sliding condition. The worn surfaces, counterpart transfer films and wear debris were studied by scanning electron microscopy and X-ray photoelectron spectroscopy. It was found that the increase of nano- ZrO2 content could effectively reduce the coefficient of friction and enhance the anti-wear ability of PTFEPPS composites. Especially, the best tribological properties of the composites were obtained when the particle content of nano-ZrO2 was 10 vol%, the anti-wear performance of composite is 195 times better than that of the unfilled PTFE-PPS composite. Under different conditions, the coefficient of friction of PTFE/PPS-nano-ZrO2 composites was more affected by the applied load while the wear rate was more affected by the sliding velocity.
文摘The Al2O3-ZrO2（3Y）-SiC composite ceramics used in solar thermal power were prepared by micrometric Al2O3,nano-ZrO2 and SiC powders under the condition of pressureless sintering.The bulk density and bending strength of samples with 10vol% nano-ZrO2 sintered at 1480℃ were 3.222 g/cm3 and 160.4MPa,respectively.The bending strength of samples after 7 times thermal shock tests （quenching from 1000℃ to 25℃ in air medium） is 132.0MPa,loss rate of bending strength is only 17%.The effect of nano-ZrO2 content on the microstructure and performance of Al2O3-ZrO2（3Y）-SiC composite ceramic was investigated.The experimental results show that the bending strength of samples with above 10vol% nano-ZrO2 content has decreased,because the volume expansion resulting from t-ZrO2 to m-ZrO2 phase transformation is excessive;Adding proper nano-ZrO2 would be contributed to improve the thermal shock resistance of the composite ceramics.The Al2O3-ZrO2（3Y）-SiC composite ceramic has promising potential application in solar thermal power.
基金This is a key project of high and new science and technology and supported by Science & Technology Department of Fujian Province (2004H008)
文摘Recently, more and more interest has been focused on zirconia and its characteristics. In this paper, aluminum can be successfully incorporated into nano-ZrO2 via a cationic surfactant assisted route in the earlier preparation procedure. XRD, TEM, EDS, Uv-vis and N2 adsorption-desorption analysis methods were adopted for the characterization of prepared samples. The results show that aluminum has been homogeneously incorporated into nano-ZrO2. The prepared aluminum-doped samples show a distinctive blue shift in the Uv-vis spectra compared to normal nano-ZrO2. The distinctive increase of thermal stability and a mesoporous structure were observed.
基金Innovative Team Project of Science and Technology Commission of Shanghai, China(No.06DZ05902)
文摘Nano-ZrO2 particles were modified by poly(ethylene terephalate) prepolymer(pre-PET) via polycondensation.FT-IR,TEM,and TGA results showed that pre-PET was successfully grafted on the surface of nano-ZrO2particles.Compared to the original nano-ZrO2,the grafted nano-ZrO2 had better compatibility with the polycarbonate(PC) matrix and could be dispersed more homogeneously in PC.Hence,interfacial adhesion between ZrO2 and PC was enhanced.The mechanical properties of the resultant PC/nano-ZrO2 composite like tensile strength and notched impact strength were greatly improved.Calculated respectively from tensile yield stress PC/nano-ZrO2 composites,the interfacial interaction parameter B was employed to quantitatively characterize the effective interfacial interaction between the nano-ZrO2 and PC matrix.
文摘Catalyst plays an important role in the dehydration of N-（hydroxylethyl）pyrrolidone （NHP） to prepare N-vinyl-pyrrolidone （NVP）. At present, NVP yield is only about 30% on commercial ZrO2 catalyst. A coupled precipitation and solid dispersion technique was designed to prepare the nano-ZrO2 catalyst, in which rare earth metal oxides （REOx） was used as electronic promoter. The results indicated that the catalyst doped REOx （S-1.0） exhibits the optimum performance of NHP dehydration at moderate conditions. NHP conversion and NVP selectivity are respectively 97.0%, 82.3%. Of special interest is that the indexes of the catalyst （S-1.0-1.0） are up to 98.4% and 89.2% respectively. Furthermore, this catalyst bears the good stability. It means that nano-ZrO2 doped REOx catalyst might be a potential commercial catalyst for the NHP dehydration.
基金financially supported by Anhui Province Key Research and Development Program(No.2022i01020002)the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(No.22KJB180020)+2 种基金the Scientific Research Project of Anhui Polytechnic University(No.2022YQQ072)Anhui Provincial Higher Education Institutes(No.2023AH050941)the Advanced Fiber Materials Engineering Research Center of Anhui Province(No.2023AFMC20)。
文摘Waterborne microbial contamination represents a significant global environmental challenge.Microorganisms can induce water pollution,precipitating infectious disease outbreaks and posing a substantial threat to human health.Currently,the excessive use of conventional antibiotics has resulted in the emergence of bacterial resistance,posing a challenge to the design and development of antimicrobial agents with high antibacterial efficacy in diverse water such as rivers,lakes,and wastewater from microbiology laboratories.Bimetallic nanomaterials,that amalgamate the distinctive characteristics of diverse metals,are garnering attention due to their synergistic properties.In this study,PVP-FeMo_(2)S_(3)(PVP:Polyvinylpyrrolidone)and PVP-ZnMo_(2)S_(3)nanocrystals were synthesized by a high-temperature reaction.The prepared nanocrystals exhibited excellent biocompatibility,regular morphology,long-term stability,and remarkable antibacterial e ects.The bacterial biofilms could be eradicated by the combination of photothermal(PTT)and photodynamic synergistic e ects of PVP-FeMo_(2)S_(3)and PVP-ZnMo_(2)S_(3)nanocrystals.PVP-ZnMo_(2)S_(3)nanocrystals exhibited enhanced PTT conversion efficiency for water treatment.Remarkably,even after 20 cycles of recycling,PVP-ZnMo_(2)S_(3)retained substantial antibacterial e cacy.The excellent biosafety of PVP-ZnMo_(2)S_(3)further guarantees the safety of water quality post-treatment.Thus,PVP-ZnMo_(2)S_(3)bimetallic nanocrystals can serve as a novel antimicrobial agent for the treatment of microbial contamination in water.This study offers a potential strategy to mitigate secondary water pollution and prevent the development of drug resistance among pathogenic microorganisms.
基金supported by the earmarked fund for China Agricultural Research System (CARS-45-16).
文摘Cyprinid herpesvirus 2(CyHV-2),a member of the Alloherpesviridae family belonging to the genus Cyprinivirus,was initially isolated from goldfish(Carassius auratus)and has been recently emerging as a virulent pathogen for cultured prussian carp(Carassius auratus gibelio)world-wide.In this study,a novel and effective method for concentration and quantification of live CyHV-2 virions from water was successfully established through coupling the iron flocculation with real time qPCR assay.Then,the shedding intensity of CyHV-2 in fish-tank water from artificially-challenged goldfish(25 fish/20 L)was monitored continuously for 7 days on a daily basis through quantitating viral genomic copy numbers by qPCR,and the maximum shedding level was determined to be 105 copies/L.Horizontal transmission research system was established by inoculating healthy goldfish in water spiked with serial dilution of CyHV-2 virions ranging from 107 to 103 copies/L.Our results indicated that water-borne CyHV-2 efficiently caused the infection of tested goldfish even in a concentration of 103 copies/L,and the overall transmission efficacy was not linearly correlated with the level of input virus in the fish tank.Commercial disinfectant Composite Sodium Chlorite Powder(CSCP)has been widely applied in aquaculture to control microbial infection through direct spill in the water,and its effect in inactivating the CyHV-2 infectivity remains unknown.We further determined that the EC50 of CSCP against 3.89 TCID50/mL CyHV-2 was close to 15.625μg/mL in vitro,and application of CSCP in a level as high as 60μg/mL(the safety concentration of CSCP for goldfish)couldn’t protect goldfish from CyHV-2 challenge through immersion.Thus,the disinfectant CSCP was regarded as none-effective for blocking CyHV-2 transmission in water during epidemic.Overall,our data provided quantitative data to demonstrate the shedding intensity of CyHV-2 in water,and CSCP was shown to be not effective in blocking water-borne horizontal transmission of CyHV-2 in goldfish.The virus-concentration protocol and virus-inhibition assay established here also paved the way for evaluating more commercial disinfectants in their effects in blocking water-borne horizontal transmission of CyHV-2.
