The low utilization rate of pesticides makes the migration of pesticides in water and soil,which brings great harm to the ecosystem.The development of pesticide carriers with good drug loading capacity and release con...The low utilization rate of pesticides makes the migration of pesticides in water and soil,which brings great harm to the ecosystem.The development of pesticide carriers with good drug loading capacity and release control abil-ity is an effective method to realize effective utilization of pesticides and reduce pesticide losses.In this work,fosthiazate-stearic acid/expanded perlite sustained-release particles were successfully prepared by vacuum impregnation using expanded perlite(EP)as carrier,fosthiazate(FOS)as model pesticide and stearic acid(SA)as hydrophobic matrix.The structure and morphology of the samples were studied by BET,FT-IR,TGA,XRD,DSC and SEM.The effects of different mass ratios of FOS to SA on loading capacity and release rate at 24 h were investigated.The sustained release behavior of FOS-SA/EP at different temperatures and pH values was investigated by static dialysis bag method.The results showed that FOS and SA were adsorbed in EP pores by physical interaction.With the mass ratios of FOS to SA decreasing from 7:3 to 3:7,the 24 h release rate of FOS-SA/EP decreased from 18.77%to 8.05%,and the drug loading decreased from 461.32 to 130.99 mg/g.FOS-SA/EP showed obvious temperature response at 25℃,30℃ and 35℃,the cumulative release rate(CRR)of 200 h were 33.38%,41.50%and 51.17%,respectively.When pH=5,the CRR of FOS was higher than that of pH=7,and the CRR of FOS for 200 h were 49.01%and 30.12%,respectively.At different temperatures and pH=5,the release mechanism of FOS-SA/EP belongs to the Fickian diffusion mechanism;When pH=7,the diffusion mechanism is dominant,and the dissolution mechanism is complementary.展开更多
The oil sorption capacity of composite materials made up of different polymeric fabrics (namely acrylic fabric (AF), polypropylene nonwoven (PP), and silk stocking (SS) as composite out-packing materials) and expanded...The oil sorption capacity of composite materials made up of different polymeric fabrics (namely acrylic fabric (AF), polypropylene nonwoven (PP), and silk stocking (SS) as composite out-packing materials) and expanded perlite (EP) was evaluated for oil removal from the water. The effects of sorbent dosage, desorption time, oil amount in the water, and contact time on composite materials sorption were investigated. The results showed that the optimum quantity of EP was between 0.5 g and 1.0 g for 25 cm2 polymeric fabrics bags. Oil removal efficiency for 6 L/m2 of oil amount in the water was 52%-72%, 44%-63%, and 37%-48% for AF, PP, and SS composite materials, respectively. Oil/water selectivity analysis of different composite materials showed that AF composite material had a very high degree of hydrophobicity and oil sorption capacity of approximately 10.17 g/g. Both oil sorption kinetics and equilibrium studies were carried out, and the equilibrium process of composite materials was described well by the Langmuir isotherm, and the oil sorption kinetics of composite materials showed good correlation coefficients for the pseudo-second order kinetic model. Intra-particle diffusion studies showed that oil sorption mechanism was controlled by the three processes, involving in external liquid membrane diffusion, surface sorption, and intra-particle diffusion.展开更多
A magnetic mesoporous expanded perlite-based(EPd-APTES@Fe3 O_(4))composite was designed and synthesized as a novel adsorbent for enrichment of rare earth ions in aqueous solution.Effect of various factors including th...A magnetic mesoporous expanded perlite-based(EPd-APTES@Fe3 O_(4))composite was designed and synthesized as a novel adsorbent for enrichment of rare earth ions in aqueous solution.Effect of various factors including the pH of solution,contact time and adsorbent dosage on the adsorption behaviors of yttrium(Ⅲ)by the EPd-APTES@Fe3 O_(4) nano-material composites from aqueous solution was investigated.The maximum adsorption capacity of the as-prepared materials for yttrium(Ⅲ)ions was 383.2 mg/g.Among the various isotherm models,the Freundlich isotherm model could well described for the adsorption of the rare ea rth ions at pH 5.5 and 298.15 K.The kinetic analysis indicated that the adsorption process followed the pseudo-second order kinetics model,and the rate-determining step might be chemical adsorption.Thermodynamic parameters declared that the adsorption process was endothermic.In addition,Fourier transform infrared spectroscopy(FTIR),X-ray photoelectron spectroscopy(XPS)and the quantum chemical calculation indicated that the yttrium(Ⅲ)ions were captured on the EPd-APTES@Fe3 O_(4) surface mainly by coordination with functional group of-NH2.More importantly,the adsorption-desorption studies indicated that the EPd-APTES@Fe3 O_(4) nano-material composites had a high stability and good recyclability.展开更多
The International Energy Agency(IEA)states that global energy consumption will increase by 53%by 2030.Turkey has 70%of the world’s perlite reserves,and in order to reduce energy consumption a thermal insulation panel...The International Energy Agency(IEA)states that global energy consumption will increase by 53%by 2030.Turkey has 70%of the world’s perlite reserves,and in order to reduce energy consumption a thermal insulation panel was developed in Turkey using different particle sizes of expanded perlite(EP).In this study,0–1.18 mm(powder)and 0–3 mm(granular)EP particle sizes were selected,since they have the lowest thermal conductivity coefficients among all the particle sizes.In addition,an alkali activator solution was used as a binder in the mixtures.The alkaline activator solution was obtained by mixing sodium hydroxide solution(6,8,10,and 12 mol·L−1)and sodium silicate(Module 3)at the different ratios of Na2SiO3 to NaOH of 1,1.5,2,and 2.5.This study aimed to experimentally determine the optimum binder and distribution ratio of EP,with the lowest coefficient of thermal conductivity and the lowest density.The lowest thermal conductivity and the lowest density were determined as 0.04919 W·m−1·K−1 and 133.267 kg/m3,respectively,in the sample prepared with 83.33%powder-size EP,6 mol·L−1 sodium hydroxide solution,and ratio of Na2SiO3 to NaOH of 1.5.The density,thermal conductivity,and compressive strength of the sample showed the same trends of behavior when the Na2SiO3 to NaOH ratio was increased.In addition,the highest compressive strength was measured in 12 mol·L−1 NaOH concentration regardless of particle size.In conclusion,the study predicts that the EP-based thermal insulation panel can be used as an insulation material in the construction industry according to the TS825 Thermal Insulation Standard.展开更多
基金supported by the Guangdong Provincial Science and Technology Project(No.2015B020215012)State Key Laboratory of Woody Oil Resource Utilization,Co-Built by Provincial and Ministry of China(No.GZKF202108)National Natural Science Foundation of China(32101475).
文摘The low utilization rate of pesticides makes the migration of pesticides in water and soil,which brings great harm to the ecosystem.The development of pesticide carriers with good drug loading capacity and release control abil-ity is an effective method to realize effective utilization of pesticides and reduce pesticide losses.In this work,fosthiazate-stearic acid/expanded perlite sustained-release particles were successfully prepared by vacuum impregnation using expanded perlite(EP)as carrier,fosthiazate(FOS)as model pesticide and stearic acid(SA)as hydrophobic matrix.The structure and morphology of the samples were studied by BET,FT-IR,TGA,XRD,DSC and SEM.The effects of different mass ratios of FOS to SA on loading capacity and release rate at 24 h were investigated.The sustained release behavior of FOS-SA/EP at different temperatures and pH values was investigated by static dialysis bag method.The results showed that FOS and SA were adsorbed in EP pores by physical interaction.With the mass ratios of FOS to SA decreasing from 7:3 to 3:7,the 24 h release rate of FOS-SA/EP decreased from 18.77%to 8.05%,and the drug loading decreased from 461.32 to 130.99 mg/g.FOS-SA/EP showed obvious temperature response at 25℃,30℃ and 35℃,the cumulative release rate(CRR)of 200 h were 33.38%,41.50%and 51.17%,respectively.When pH=5,the CRR of FOS was higher than that of pH=7,and the CRR of FOS for 200 h were 49.01%and 30.12%,respectively.At different temperatures and pH=5,the release mechanism of FOS-SA/EP belongs to the Fickian diffusion mechanism;When pH=7,the diffusion mechanism is dominant,and the dissolution mechanism is complementary.
基金National Important Science & Technology Specific Projects of China ( No. 2009ZX07317-006-02,No. 2009ZX07318-008-007)State Key Laboratory of Urban Water Resource and Environment,Harbin Institute of Technology,China ( No. 2013DX06)
文摘The oil sorption capacity of composite materials made up of different polymeric fabrics (namely acrylic fabric (AF), polypropylene nonwoven (PP), and silk stocking (SS) as composite out-packing materials) and expanded perlite (EP) was evaluated for oil removal from the water. The effects of sorbent dosage, desorption time, oil amount in the water, and contact time on composite materials sorption were investigated. The results showed that the optimum quantity of EP was between 0.5 g and 1.0 g for 25 cm2 polymeric fabrics bags. Oil removal efficiency for 6 L/m2 of oil amount in the water was 52%-72%, 44%-63%, and 37%-48% for AF, PP, and SS composite materials, respectively. Oil/water selectivity analysis of different composite materials showed that AF composite material had a very high degree of hydrophobicity and oil sorption capacity of approximately 10.17 g/g. Both oil sorption kinetics and equilibrium studies were carried out, and the equilibrium process of composite materials was described well by the Langmuir isotherm, and the oil sorption kinetics of composite materials showed good correlation coefficients for the pseudo-second order kinetic model. Intra-particle diffusion studies showed that oil sorption mechanism was controlled by the three processes, involving in external liquid membrane diffusion, surface sorption, and intra-particle diffusion.
基金the National Natural Science Foundation of China(No.51704042)National Key Research and Development Program(No.2018YFC1903401)+3 种基金Project of jiangxi Provincial Department of Science and Technology(No.20202BABL204018)Project of Education Commission of Jiangxi Province of China(No.GJJ170488)Ganzhou Innovative Talents Plane,Natural Science Foundation ofJiangxi University of Science and Technology(No.jxxjbs17042)National College Students’Innovation and Entrepreneurship Training Program(Nos.201810407001,201810407003)。
文摘A magnetic mesoporous expanded perlite-based(EPd-APTES@Fe3 O_(4))composite was designed and synthesized as a novel adsorbent for enrichment of rare earth ions in aqueous solution.Effect of various factors including the pH of solution,contact time and adsorbent dosage on the adsorption behaviors of yttrium(Ⅲ)by the EPd-APTES@Fe3 O_(4) nano-material composites from aqueous solution was investigated.The maximum adsorption capacity of the as-prepared materials for yttrium(Ⅲ)ions was 383.2 mg/g.Among the various isotherm models,the Freundlich isotherm model could well described for the adsorption of the rare ea rth ions at pH 5.5 and 298.15 K.The kinetic analysis indicated that the adsorption process followed the pseudo-second order kinetics model,and the rate-determining step might be chemical adsorption.Thermodynamic parameters declared that the adsorption process was endothermic.In addition,Fourier transform infrared spectroscopy(FTIR),X-ray photoelectron spectroscopy(XPS)and the quantum chemical calculation indicated that the yttrium(Ⅲ)ions were captured on the EPd-APTES@Fe3 O_(4) surface mainly by coordination with functional group of-NH2.More importantly,the adsorption-desorption studies indicated that the EPd-APTES@Fe3 O_(4) nano-material composites had a high stability and good recyclability.
基金The authors gratefully acknowledge the financial assistance of the Scientific and Technical Research Council(TUBITAK)of Turkey provided under Project:115M041.
文摘The International Energy Agency(IEA)states that global energy consumption will increase by 53%by 2030.Turkey has 70%of the world’s perlite reserves,and in order to reduce energy consumption a thermal insulation panel was developed in Turkey using different particle sizes of expanded perlite(EP).In this study,0–1.18 mm(powder)and 0–3 mm(granular)EP particle sizes were selected,since they have the lowest thermal conductivity coefficients among all the particle sizes.In addition,an alkali activator solution was used as a binder in the mixtures.The alkaline activator solution was obtained by mixing sodium hydroxide solution(6,8,10,and 12 mol·L−1)and sodium silicate(Module 3)at the different ratios of Na2SiO3 to NaOH of 1,1.5,2,and 2.5.This study aimed to experimentally determine the optimum binder and distribution ratio of EP,with the lowest coefficient of thermal conductivity and the lowest density.The lowest thermal conductivity and the lowest density were determined as 0.04919 W·m−1·K−1 and 133.267 kg/m3,respectively,in the sample prepared with 83.33%powder-size EP,6 mol·L−1 sodium hydroxide solution,and ratio of Na2SiO3 to NaOH of 1.5.The density,thermal conductivity,and compressive strength of the sample showed the same trends of behavior when the Na2SiO3 to NaOH ratio was increased.In addition,the highest compressive strength was measured in 12 mol·L−1 NaOH concentration regardless of particle size.In conclusion,the study predicts that the EP-based thermal insulation panel can be used as an insulation material in the construction industry according to the TS825 Thermal Insulation Standard.
