Ce0.6Zr0.4O2 solid solution ultrafine particle was prepared in the cyclohexane/water/OP-10/n-hexanol reversed microemulsion. The quasi-ternary phase diagram investigations showed that the system has narrow W/O type mi...Ce0.6Zr0.4O2 solid solution ultrafine particle was prepared in the cyclohexane/water/OP-10/n-hexanol reversed microemulsion. The quasi-ternary phase diagram investigations showed that the system has narrow W/O type microemulison region, so it is the proper system to prepare Ce0.6Zr0.4O2 solid solution ultrafine particle. Some physical-chemical techniques such as TG/DTA, XRD, BET, and HRTEM are used to characterize the resultant powders. The results show that the fluorite cubic Ce0.6Zr0.4O2 solid solution is obtained at 400 ℃. The surface area is （146.7 m^2·g^-1）, which is higher than the surface area for sol-gel prepared sample （59.5m^2·g^-1）. HRTEM images indicated that the Ce0.6Zr0.4O2 solid solution ultrafine particle is well-crystallized, narrow size distribution, less agglomeration, within mean size of 5 -7 nm.展开更多
Nano-sized titania powders have been prepared by hydrolysis of tetrabutyl titanate in the droplet of water/OP-7/pentanol/cyclohexane microemulsion system.The effects of ingredient change on the water drop size and par...Nano-sized titania powders have been prepared by hydrolysis of tetrabutyl titanate in the droplet of water/OP-7/pentanol/cyclohexane microemulsion system.The effects of ingredient change on the water drop size and particle size were investigated.The prepared TiO_2 was in the form of anatase after annealing.TiO_2 was characterized by TG-TGA, FTIR,XRD to measure the transformation temperature,surface adsorption and average size.展开更多
Dispersed cuprite （Cu2O） nanowhiskers were synthesized in a water/butanol/cyclohexane/cetyl trimethyl ammonium bromide （CTAB） water-in-oil microemulsion system at 25℃. The nanowhiskers with a diameter of about 8 ...Dispersed cuprite （Cu2O） nanowhiskers were synthesized in a water/butanol/cyclohexane/cetyl trimethyl ammonium bromide （CTAB） water-in-oil microemulsion system at 25℃. The nanowhiskers with a diameter of about 8 am exhibit a well-crystallized one-dimensional （1D） structure over several hundreds nanometers in length and mainly grow along the 〈111〉 direction. However, without CTAB, only cubic and hexagonal bulks are obtained. Without emulsifier, short and thick nanowhiskers can be prepared but they are apt to agglomerate. The possible growth mechanism of Cu2O nanowhiskers is speculated. The surfactant and the microemulsion system are related to the 1D shape formation and the even dispersion of Cu2O nanomaterials, respectively.展开更多
FTIR method was used in this paper to investigate the structure of lysozyme in D2O solution and in microemulsions.It was found from the subtraction spectra that the Amide Ⅰband shifts to lower wavenumbers in microemu...FTIR method was used in this paper to investigate the structure of lysozyme in D2O solution and in microemulsions.It was found from the subtraction spectra that the Amide Ⅰband shifts to lower wavenumbers in microemulsions. The assignment of deconvoluted AmideⅠbund was given.The curve-fitting resulte show that the α-helix structure of lysozyme is reduced a lot in microemulsions.展开更多
Nano-SiO_2 with high activity and mesopores was prepared through sol-gel synthesis followed by low-temperatureheat treatment and ball milling firstly in our experiments. TEM was performed to measure particle sizes. Ni...Nano-SiO_2 with high activity and mesopores was prepared through sol-gel synthesis followed by low-temperatureheat treatment and ball milling firstly in our experiments. TEM was performed to measure particle sizes. Nitrogenadsorption experiments were carried out to estimate specific surface area, porous distribution and porous ratio by BETand BJH methods. The content of Si-OH in SiO_2 surface was calculated by analysis of the results of hydrogen-oxygencontent mensuration (HOCM). As a result, appropriate heat treatment system and ball milling time are important topreparation for nano-SiO_2 with high activity and mesopores, which are 5～50 nm particles, 5～6 nm average aperture,85%～93% porous ratio, and 51%～55% Si-OH content in surface. Nano-SiO_2 with that structure has high surfaceenergy and activity. This process, which has simple facilities and operation rules, is a new way of preparation fornano-SiO_2 with high activity and mesopores.展开更多
Single-phase homogeneous Ce1-x ZrxO2 solid versed microemulsion method. The structural properties solutions with various compositions were synthesized using the reand performance of Ce1- xZrxO2 were studied using XRD,...Single-phase homogeneous Ce1-x ZrxO2 solid versed microemulsion method. The structural properties solutions with various compositions were synthesized using the reand performance of Ce1- xZrxO2 were studied using XRD, BET, SEM, HRTEM, TPR and CO oxidation measurements. The results show that in the range of x = 0.4 - 0.5 and x = 0.6 - 1.0, the solid solutions posses the cubic and the tetragonal phase structure, respectively, Solids obtained by the reversed microemulsion method were more homogeneous on the whole range of composition, XRD investigations of the prepared materials did not show segregation of cerium or zirconium oxides, Highly uniform nanosize solid solution particles of ceria-zirconia with high specific area （146.7 m^2·g^-1） were attained under the conditions of this study. The TPR results and CO oxidation measurements indicate that the performance of the CeO2-ZrO2 mixed oxides is strongly related to the composition and structure of the oxides. Enhancement of the activity was found for the catalyst prepared by reversed microemulsion method as compared to the sample prepared by sol-gel method.展开更多
The method of synchrotron radiation small-angle X-ray scattering (SR-SAXS) has been used to obtain structural information on the system of bis (2-ethylhexyl) sulfosuccinate (AOT)/H2O/isooctane. By using the Guinier pl...The method of synchrotron radiation small-angle X-ray scattering (SR-SAXS) has been used to obtain structural information on the system of bis (2-ethylhexyl) sulfosuccinate (AOT)/H2O/isooctane. By using the Guinier plot (Ln I (q) versus q(2)) on the data sets in a defined small q range (0.03-0.06 Angstrom (-1)), the gyration radius at different water/surfactant molar ratio, W-0, was obtained. With the increase of W-0, the gyration radius (R-g) increased at the range of 23.2 similar to 52.7 Angstrom.展开更多
The mechanical properties of wood flour/high-density polyethylene composites(WPC)were improved by adding a small amount of nano-SiO_(2)to obtain a network-structured WPC with a continuous honeycomb-like nano-SiO_(2)ne...The mechanical properties of wood flour/high-density polyethylene composites(WPC)were improved by adding a small amount of nano-SiO_(2)to obtain a network-structured WPC with a continuous honeycomb-like nano-SiO_(2)network.The wood flour was modified with a fire retardant(a mixture of sodium octabonate and amidine urea phosphate)to improve its fire retardancy.The flexural properties,creep resistance,thermal expansion,and fire retardancy of the WPC were compared to a control(WPCCTRL)without nano-SiO_(2)or fire retardant.The flexural strength and modulus of the WPC containing only 0.55 wt.%nano-SiO_(2)were 6.6%and 9.1%higher than the control,respectively,while the creep strain and thermal expansion rate at 90°C were 33.8%and 13.6%lower,respectively.The cone calorimetry tests revealed that the nano-SiO_(2)network physically shielded the WPC,giving it lower heat release and smoke production rates.The thermal expansion was further decreased by incorporating fire retardants into the WPC,which showed the lowest total heat release and total smoke production and the highest mass retention.This study demonstrates a facile procedure for producing WPC with desired performances by forming a continuous honeycomb-like network by adding a small amount of nanoparticles.展开更多
Nanoparticles have been widely used in polymer gel systems in recent years to improve gelation performance under high-temperature reservoir conditions. However, different types of nanoparticles have different effects ...Nanoparticles have been widely used in polymer gel systems in recent years to improve gelation performance under high-temperature reservoir conditions. However, different types of nanoparticles have different effects on their gelation performance, which has been little researched. In this study, the high-temperature gelation performance, chemical structure, and microstructure of polymer gels prepared from two nanomaterials (i.e., nano-SiO_(2) and nano-TiO_(2)) were measured. The conventional HPAM/PEI polymer gel system was employed as the control sample. Results showed that the addition of nano-TiO_(2) could significantly enhance the gel strength of HPAM/PEI gel at 80 ℃. The gel strength of the enhanced HPAM/PEI gel with 0.1 wt% nano-TiO_(2) could reach grade I. The system also had excellent high-temperature stability at 150 ℃. The enhanced HPAM/PEI gel with 0.02 wt% nano-TiO_(2) reached the maximum gel strength at 150 ℃ with a storage modulus (G′) of 15 Pa, which can meet the need for efficient plugging. However, the nano-SiO_(2) enhanced HPAM/PEI polymer gel system showed weaker gel strength than that with nano-TiO_(2) at both 80 and 150 ℃ with G′ lower than 5 Pa. Microstructures showed that the nano-TiO_(2) enhanced HPAM/PEI gel had denser three-dimensional (3D) mesh structures, which makes the nano-TiO_(2) enhanced HPAM/PEI gel more firmly bound to water. The FT-IR results also confirmed that the chemical structure of the nano-TiO_(2) enhanced HPAM/PEI gel was more thermally stable than nano-SiO_(2) since there was a large amount of –OH groups on the structure surface. Therefore, nano-TiO_(2) was more suitable as the reinforcing material for HPAM/PEI gels for high-temperature petroleum reservoir conformance improvement.展开更多
Calcium fluoride nanoparticles were synthesized by water/cetyltrimethylammonium bromide (CTAB)/2-octanol microemulsion systems. X-ray powder diffraction analysis showed that the products were a single phase. The resul...Calcium fluoride nanoparticles were synthesized by water/cetyltrimethylammonium bromide (CTAB)/2-octanol microemulsion systems. X-ray powder diffraction analysis showed that the products were a single phase. The result of scanning electron microscopy confirmed that the average sizes of the calcium fluoride particles were below 100 nm in diameter. With decreasing water content and reaction time, the particle sizes decreased.展开更多
文摘Ce0.6Zr0.4O2 solid solution ultrafine particle was prepared in the cyclohexane/water/OP-10/n-hexanol reversed microemulsion. The quasi-ternary phase diagram investigations showed that the system has narrow W/O type microemulison region, so it is the proper system to prepare Ce0.6Zr0.4O2 solid solution ultrafine particle. Some physical-chemical techniques such as TG/DTA, XRD, BET, and HRTEM are used to characterize the resultant powders. The results show that the fluorite cubic Ce0.6Zr0.4O2 solid solution is obtained at 400 ℃. The surface area is （146.7 m^2·g^-1）, which is higher than the surface area for sol-gel prepared sample （59.5m^2·g^-1）. HRTEM images indicated that the Ce0.6Zr0.4O2 solid solution ultrafine particle is well-crystallized, narrow size distribution, less agglomeration, within mean size of 5 -7 nm.
文摘Nano-sized titania powders have been prepared by hydrolysis of tetrabutyl titanate in the droplet of water/OP-7/pentanol/cyclohexane microemulsion system.The effects of ingredient change on the water drop size and particle size were investigated.The prepared TiO_2 was in the form of anatase after annealing.TiO_2 was characterized by TG-TGA, FTIR,XRD to measure the transformation temperature,surface adsorption and average size.
基金This work was financially supported by the National Natural Science Foundation of China (No. 20207002).
文摘Dispersed cuprite （Cu2O） nanowhiskers were synthesized in a water/butanol/cyclohexane/cetyl trimethyl ammonium bromide （CTAB） water-in-oil microemulsion system at 25℃. The nanowhiskers with a diameter of about 8 am exhibit a well-crystallized one-dimensional （1D） structure over several hundreds nanometers in length and mainly grow along the 〈111〉 direction. However, without CTAB, only cubic and hexagonal bulks are obtained. Without emulsifier, short and thick nanowhiskers can be prepared but they are apt to agglomerate. The possible growth mechanism of Cu2O nanowhiskers is speculated. The surfactant and the microemulsion system are related to the 1D shape formation and the even dispersion of Cu2O nanomaterials, respectively.
文摘FTIR method was used in this paper to investigate the structure of lysozyme in D2O solution and in microemulsions.It was found from the subtraction spectra that the Amide Ⅰband shifts to lower wavenumbers in microemulsions. The assignment of deconvoluted AmideⅠbund was given.The curve-fitting resulte show that the α-helix structure of lysozyme is reduced a lot in microemulsions.
文摘Nano-SiO_2 with high activity and mesopores was prepared through sol-gel synthesis followed by low-temperatureheat treatment and ball milling firstly in our experiments. TEM was performed to measure particle sizes. Nitrogenadsorption experiments were carried out to estimate specific surface area, porous distribution and porous ratio by BETand BJH methods. The content of Si-OH in SiO_2 surface was calculated by analysis of the results of hydrogen-oxygencontent mensuration (HOCM). As a result, appropriate heat treatment system and ball milling time are important topreparation for nano-SiO_2 with high activity and mesopores, which are 5～50 nm particles, 5～6 nm average aperture,85%～93% porous ratio, and 51%～55% Si-OH content in surface. Nano-SiO_2 with that structure has high surfaceenergy and activity. This process, which has simple facilities and operation rules, is a new way of preparation fornano-SiO_2 with high activity and mesopores.
文摘Single-phase homogeneous Ce1-x ZrxO2 solid versed microemulsion method. The structural properties solutions with various compositions were synthesized using the reand performance of Ce1- xZrxO2 were studied using XRD, BET, SEM, HRTEM, TPR and CO oxidation measurements. The results show that in the range of x = 0.4 - 0.5 and x = 0.6 - 1.0, the solid solutions posses the cubic and the tetragonal phase structure, respectively, Solids obtained by the reversed microemulsion method were more homogeneous on the whole range of composition, XRD investigations of the prepared materials did not show segregation of cerium or zirconium oxides, Highly uniform nanosize solid solution particles of ceria-zirconia with high specific area （146.7 m^2·g^-1） were attained under the conditions of this study. The TPR results and CO oxidation measurements indicate that the performance of the CeO2-ZrO2 mixed oxides is strongly related to the composition and structure of the oxides. Enhancement of the activity was found for the catalyst prepared by reversed microemulsion method as compared to the sample prepared by sol-gel method.
文摘The method of synchrotron radiation small-angle X-ray scattering (SR-SAXS) has been used to obtain structural information on the system of bis (2-ethylhexyl) sulfosuccinate (AOT)/H2O/isooctane. By using the Guinier plot (Ln I (q) versus q(2)) on the data sets in a defined small q range (0.03-0.06 Angstrom (-1)), the gyration radius at different water/surfactant molar ratio, W-0, was obtained. With the increase of W-0, the gyration radius (R-g) increased at the range of 23.2 similar to 52.7 Angstrom.
基金supported by the National Key Research and Development Program of China(Nos.2019YFD1101204 and 2019YFD1101203)the National Natural Science Foundation of China(Nos.31870547 and 31901251)+3 种基金the Project funded by China Postdoctoral Science Foundation(No.2019M652919)the Research and Development Program in Key Areas of Guangdong Province(No.2020B020216002)the Project of Guangzhou Municipal Key Laboratory of Woody Biomass Functional New Materials(No.201905010005)the Project of Key Disciplines of Forestry Engineering of Bureau of Education of Guangzhou Municipality.
文摘The mechanical properties of wood flour/high-density polyethylene composites(WPC)were improved by adding a small amount of nano-SiO_(2)to obtain a network-structured WPC with a continuous honeycomb-like nano-SiO_(2)network.The wood flour was modified with a fire retardant(a mixture of sodium octabonate and amidine urea phosphate)to improve its fire retardancy.The flexural properties,creep resistance,thermal expansion,and fire retardancy of the WPC were compared to a control(WPCCTRL)without nano-SiO_(2)or fire retardant.The flexural strength and modulus of the WPC containing only 0.55 wt.%nano-SiO_(2)were 6.6%and 9.1%higher than the control,respectively,while the creep strain and thermal expansion rate at 90°C were 33.8%and 13.6%lower,respectively.The cone calorimetry tests revealed that the nano-SiO_(2)network physically shielded the WPC,giving it lower heat release and smoke production rates.The thermal expansion was further decreased by incorporating fire retardants into the WPC,which showed the lowest total heat release and total smoke production and the highest mass retention.This study demonstrates a facile procedure for producing WPC with desired performances by forming a continuous honeycomb-like network by adding a small amount of nanoparticles.
基金supported by the Natural Science Foundation of Xinjiang Uygur Autonomous Region(No.2022D01A250)the CNPC Strategic Cooperation Science and Technology Project(ZLZX2020-01-04-04).
文摘Nanoparticles have been widely used in polymer gel systems in recent years to improve gelation performance under high-temperature reservoir conditions. However, different types of nanoparticles have different effects on their gelation performance, which has been little researched. In this study, the high-temperature gelation performance, chemical structure, and microstructure of polymer gels prepared from two nanomaterials (i.e., nano-SiO_(2) and nano-TiO_(2)) were measured. The conventional HPAM/PEI polymer gel system was employed as the control sample. Results showed that the addition of nano-TiO_(2) could significantly enhance the gel strength of HPAM/PEI gel at 80 ℃. The gel strength of the enhanced HPAM/PEI gel with 0.1 wt% nano-TiO_(2) could reach grade I. The system also had excellent high-temperature stability at 150 ℃. The enhanced HPAM/PEI gel with 0.02 wt% nano-TiO_(2) reached the maximum gel strength at 150 ℃ with a storage modulus (G′) of 15 Pa, which can meet the need for efficient plugging. However, the nano-SiO_(2) enhanced HPAM/PEI polymer gel system showed weaker gel strength than that with nano-TiO_(2) at both 80 and 150 ℃ with G′ lower than 5 Pa. Microstructures showed that the nano-TiO_(2) enhanced HPAM/PEI gel had denser three-dimensional (3D) mesh structures, which makes the nano-TiO_(2) enhanced HPAM/PEI gel more firmly bound to water. The FT-IR results also confirmed that the chemical structure of the nano-TiO_(2) enhanced HPAM/PEI gel was more thermally stable than nano-SiO_(2) since there was a large amount of –OH groups on the structure surface. Therefore, nano-TiO_(2) was more suitable as the reinforcing material for HPAM/PEI gels for high-temperature petroleum reservoir conformance improvement.
文摘Calcium fluoride nanoparticles were synthesized by water/cetyltrimethylammonium bromide (CTAB)/2-octanol microemulsion systems. X-ray powder diffraction analysis showed that the products were a single phase. The result of scanning electron microscopy confirmed that the average sizes of the calcium fluoride particles were below 100 nm in diameter. With decreasing water content and reaction time, the particle sizes decreased.
