Based on the study of a new type of conducting polymer poly (3,4-ethylenedioxythiophene) (PEDOT),we focussed on the preparation and characteristics of PEDOT nanoparticles made by reversed micelle method.Moreover,w...Based on the study of a new type of conducting polymer poly (3,4-ethylenedioxythiophene) (PEDOT),we focussed on the preparation and characteristics of PEDOT nanoparticles made by reversed micelle method.Moreover,we deeply investigated the optical,electrical and the thermal stability of PEDOT nanoparticles.The main results are as follows: the small-sized PEDOT nanoparticles were prepared and utilized by different methods,such as ultraviolet/visible (UV-Vis) spectroscopy,Fourier-transform infrared (FT- IR) spectrum,scanning electron microscopy(SEM) and so on.The results show that the amount of oxidizer,ultrasonic treatment,polymerizing temperature and doping degree can influent morphology,electrical ability and gas sensitivity of PEDOT nanoparticles.The Bragg peaks of nanoparticles at 6.7°,12.7°,25° were observed by XRD and the better orientation of molecular chain was attributed to the effective doping of toluene-p-sulfonic acid,which also resulted in an enhancement of thermal stability of nanoparticles than conventional PEDOT.展开更多
Hemeproteins encapsulated in reversed micelle formulated with di-2-ethylhexyl sulfosuccinate(AOT) was found to catalyze the polymerization of o-phenylenediamine(o-PDA) with hydrogen peroxide, whereas o-PDA catalyzed...Hemeproteins encapsulated in reversed micelle formulated with di-2-ethylhexyl sulfosuccinate(AOT) was found to catalyze the polymerization of o-phenylenediamine(o-PDA) with hydrogen peroxide, whereas o-PDA catalyzed by hemeproteins dissolved in water could only form its trimers. As the nanostructural environment in reversed micelle acts as a certain orientation surrounding medium, it offers a strong electrostatic field that alters the reductive potential of Fe 3+/Fe 2+(E m7) in the heme of hemeproteins and thus increases the catalytic activity of peroxidase accordingly. According to the results of UV-Vis, 1H NMR and FTIR, the polymer catalyzed by hemoglobin(Hb) in reversed micelle was presumed to be constructed of lines and trapeziforms alternatively.展开更多
The liquid-liquid extraction method using reverse micelles can simultaneously extract lipid and protein of oilseeds,which have become increasingly popular in recent years.However,there are few studies on mass transfer...The liquid-liquid extraction method using reverse micelles can simultaneously extract lipid and protein of oilseeds,which have become increasingly popular in recent years.However,there are few studies on mass transfer processes and models,which are helpful to better control the extraction process of oils and proteins.In this paper,mass transfer process of peanut protein extracted by bis(2-ethylhexyl)sodium sulfosuccinate(AOT)/isooctane reverse micelles was investigated.The effects of stirring speed(0,70,140,and 210 r/min),temperature of extraction(30,35,40,45,and 50℃),peanut flour particle size(0.355,0.450,0.600,and 0.900 mm)and solidliquid ratio(0.010,0.0125,0.015,0.0175,and 0.020 g/mL)on extraction rate were examined.The results showed that extraction rate increased with temperature rising,particle size reduction as well as solid-liquid ratio increase respectively,while little effect of stirring speed(P>0.05)was observed.The apparent activation energy of extraction process was calculated as 10.02 kJ/mol and Arrhenius constant(A)was 1.91 by Arrhenius equation.There was a linear relationship between reaction rate constant and the square of the inverse of initial particle radius(1/r_(0)^(2))(P<0.05).This phenomenon and this shrinking core model were anastomosed.In brief,the extraction process was controlled by the diffusion of protein from the virgin zone interface of particle through the reacted zone and it was in line with the first order reaction.Mass transfer kinetics of peanut protein extracted by reverse micelles was established and it was verified by experimental results.The results provide an important theoretical guidance for industrial production of peanut protein separation and purification.展开更多
The extraction of cytochrome C was carried out by means of phase transfer technique with three different reverse micellar systems, i.e. , a CTAB micellar solution in n butyl alcohol chloroform(volume ratio 4...The extraction of cytochrome C was carried out by means of phase transfer technique with three different reverse micellar systems, i.e. , a CTAB micellar solution in n butyl alcohol chloroform(volume ratio 4∶1), an AOT micellar solution in isooctane and a SDSS D 2EHPA micellar solution in isooctane. The extraction mechanisms were studied. The results show that the extraction mechanisms for the same proteins with different types of reverse micellar systems can be distinct. The extraction of cytochrome C with CTAB and SDSS D 2EHPA reverse micellar systems are carried out according to the mechanism of electrostatic interaction. However, in the extraction of cytochrome C with the AOT reverse micellar system, the electrostatic interaction between the protein and the surfactant is not important.展开更多
Effect of dissolved CO2 on bovine serum albumin (BSA) solubilization in the reverse micelles of sodium bis (2-ethylhexyl) sulfosuccinate (AOT) in 2,2,4-trimethylpentane (iso-octane) has been studied at 308.2 K. It was...Effect of dissolved CO2 on bovine serum albumin (BSA) solubilization in the reverse micelles of sodium bis (2-ethylhexyl) sulfosuccinate (AOT) in 2,2,4-trimethylpentane (iso-octane) has been studied at 308.2 K. It was found that BSA can be precipitated completely by CO2 while the AOT and water remain in the iso-octane continuous phase. This opens up a possibility for recovery of pure protein solids directly from reverse micellar solutions.展开更多
The interaction between amphiphilic porphyrin and phenothiazine in AOT/isooctane/ water reverse micelle was investigated by UV-Vis spectra. A new absorption complex between the two species is formed in such circumstan...The interaction between amphiphilic porphyrin and phenothiazine in AOT/isooctane/ water reverse micelle was investigated by UV-Vis spectra. A new absorption complex between the two species is formed in such circumstances, which is ascribed to the enrichment of the components by the reverse micelle. The fluorescence quenching of CHTTP by PTH becomes more efficient after the formation of the absorption complex.展开更多
Crystalline TiO2 nanoparticles were synthesized by hydrolysis of titanium tetrabutoxide in the presence of hydrochloric acid in NP-5 (Igepal CO-520)/ cyclohexane reverse micelle solution at room temperature. Pure rut...Crystalline TiO2 nanoparticles were synthesized by hydrolysis of titanium tetrabutoxide in the presence of hydrochloric acid in NP-5 (Igepal CO-520)/ cyclohexane reverse micelle solution at room temperature. Pure rutile nanoparticles were obtained at an appropriate acid concentration. The influences of various reaction conditions such as the concentration of acids, water content value (w=[H2O]/[NP-5]) on the formation, crystal phase, morphology, and size of the TiO2 particles were investigated.展开更多
The aim of this study was to detect the size changes of reverse micelles after extraction of peanut protein and their forward extraction rates. Factors that affect the size of reverse micelles and the extraction of pe...The aim of this study was to detect the size changes of reverse micelles after extraction of peanut protein and their forward extraction rates. Factors that affect the size of reverse micelles and the extraction of peanut protein were also investigated. The size of reverse micelles and the size changes were measured according to the theory of dynamic light scattering under different conditions such as different sodium bis(2-ethylhexyl) sulfosuccinate(AOT) concentrations, p H values, ion concentrations, and salt species.With the increase of AOT surfactant concentrations in a certain range, the size of empty and full reverse micelles increased and the forward extraction rate decreased. The effect of pH on empty reverse micelles was not significant. However, the effect of pH on the full reverse micelle size and forward extraction rate were significant. Its forward extraction rate increased to the maximum39.6% at pH 7.5. The increase of the salt concentration of a buffer solution in a certain range decreased the size of empty and full reverse micelles and reduced the forward extraction rate of peanut protein. Ionic species had important effects on reverse micelles and peanut protein extraction. An increase in the amount of buffer solution enlarged the empty reverse micelle size in 0.03%-0.11%(V/V). However, it did not translate to a larger reverse micelle size. The size of the empty reverse micelles containing K_2SO_2 reached 24.1 nm with a 0.19%(V/V) buffer solution added. The sizes of the full reverse micelles were larger than those of the empty reverse micelles after forward extraction. However, maximum sizes were achieved with the addition of a 0.03%(V/V) buffer solution. The amount of 0.03%(V/V) buffer solution added was appropriate for extracting peanut protein.展开更多
The dynamics of water within a nanopool of a reverse micelle is heavily affected by the amphiphilic interface.In this work,the terahertz(THz)spectra of cyclohexane/Igepal/water nonionic reverse micelle mixture are mea...The dynamics of water within a nanopool of a reverse micelle is heavily affected by the amphiphilic interface.In this work,the terahertz(THz)spectra of cyclohexane/Igepal/water nonionic reverse micelle mixture are measured by THz timedomain spectroscopy and analyzed with two Debye models and complex permittivity of background with volume ratios.Based on the fitted parameters of bulk and fast water,the molar concentration of all kinds of water molecules and hydration water molecule number per Igepal molecule are calculated.We find that slow hydration water has the highest proportion in water when the radius parameterω_(0)<10,while bulk water becomes the main component whenω_(0)≥10.The feature radius ratio of nonhydrated and hydrated water to total water nanopool is roughly obtained from 0.39 to 0.85 with increasingω_(0).展开更多
The effects of postthermal treatment and irradiation time on the structure and thermal stability of TiO2/polyacrylate nanocomposites by a sol-gel process in reverse micelles and subsequent rapid photopolymerization we...The effects of postthermal treatment and irradiation time on the structure and thermal stability of TiO2/polyacrylate nanocomposites by a sol-gel process in reverse micelles and subsequent rapid photopolymerization were investigated, and the hybrid films were characterized by thermal gravimetry analysis (TGA), X-ray photoelectron spectrum (XPS), and atomic force microscopy (AFM). XPS data suggested that the prolongation of irradiation time and the postthermal treatment promoted titania formation, with the former affecting more remarkably. TGA data showed that TiO2-hybrid films could upgrade the decomposition onset temperature (Tonset) as well as the temperature at which there is a maximum mass loss rate (Tmax). AFM data demonstrated that the inorganic titania particles with a mean diameter of 25.26-28.84 nm were homogeneously distributed in the organic matrix.展开更多
Orally administered peptides or proteins are garnering increasing preference owing to their superiority in terms of patient compliance and convenience.However,the development of oral protein formulations has stalled d...Orally administered peptides or proteins are garnering increasing preference owing to their superiority in terms of patient compliance and convenience.However,the development of oral protein formulations has stalled due to the low bioavailability of macromolecules that encounter the aggressive gastrointestinal environment and harsh mucus villi barrier.Herein,we propose an ideal reverse micelle/self-emulsifying drug delivery system(RM/SEDDS)nanoplatform that is capable of improving the oral bioavailability of hydrophilic peptides by preventing enzymatic degradation and enhancing mucosal permeability.Upon the passage through the mucus,the self-emulsifying drug delivery system with optimal surface properties effectively penetrates the viscoelastic mucosal barrier,followed by the exposure of the inner reverse micelle amphipathic vectors,which autonomously form continua with the lipidic cell membrane and facilitate the internalization of drugs.This membrane-fusion mechanism inaugurates a new way for hydrophilic peptide delivery in the free form,circumventing the traditional impediments of the cellular internalization of nanocarriers and subsequent poor release of drugs.And more importantly,reverse micelles are not spatially specific to the laden drugs,which enables their delivery for a myriad of peptide clinical drugs.In conclusion,as an exquisitely designed nanoplatform,RM/SEDDS overcomes multiple physiological barriers and opens a new path for drug cellular entry,providing new prospects for the development of oral drug delivery systems.展开更多
Gold nanoparticles with size 3-10 nm (diameter) were prepared by thereduction of HAuCl_4 in a CTAB/octane + 1-butanol/H_2O reverse micelle system using NaBH_4 as thereducing agent. The as-formed gold nanoparticle coll...Gold nanoparticles with size 3-10 nm (diameter) were prepared by thereduction of HAuCl_4 in a CTAB/octane + 1-butanol/H_2O reverse micelle system using NaBH_4 as thereducing agent. The as-formed gold nanoparticle colloid was characterized by UV/vis absorptionspectrum and transmission electron microscopy (TEM). Various capping ligands, such as alkyl-thiolswith different chain length and shape, trioctylphosphine (TOP), and pyridine are used to passivatethe gold nanoparticles for the purpose of self-organization into superstructures. It is shown thatthe ligands have a great influence on the self-organization of gold nanoparticles intosuper-lattices, and do-decanethiol C_(12)H_(25)SH is confirmed to be the best ligand for theserf-organization. Self-organization of C_(12)H_(25)SH-capped gold nanoparticles into 1D, 2D and 3Dsuperlattices has been observed on the carbon-coated copper grid by TEM without using any selectiveprecipitation process.展开更多
The steady state kinetics of the lignin peroxidase (LIP) catalyzed oxidation of veratryl alcohol (VA) by H2O2 in a sodium bis(2-ethylhexyl) sulfosuccinate (AOT)/isooctane/toluene/water reverse micellar medium ...The steady state kinetics of the lignin peroxidase (LIP) catalyzed oxidation of veratryl alcohol (VA) by H2O2 in a sodium bis(2-ethylhexyl) sulfosuccinate (AOT)/isooctane/toluene/water reverse micellar medium was studied and a comparison with the corresponding aqueous medium was made to understand the effect of the reverse micellar medium on the catalytic mechanism and kinetic parameters. Results indicated that the model reaction in the AOT reverse micelle followed the ping-pong mechanism with true kcat, Km,VA and KmH2O2 being 59.6min^-1, 13.9 mmol· L^-1 and 94.8 μmol·L^-1, respectively; inhibition of high level of H2O2 on LiP followed the reversible competitive pattern with Ki being 0.140 mmol·L^-1. The reaction mechanism and inhibition pattern in the AOT reverse micellar medium were the same as those in bulk aqueous medium, but the kinetic parameters except KmH2O2 were greatly different in the two media. The kcat and Ki values in the reverse micelle were approximately 2 and 20 times smaller than the corresponding values in the aqueous solution, but the Michaelis constant of VA was approximately 100 times greater than that in the aqueous solution. The above mentioned differences in the kinetic parameters were caused by the microheterogeneity and the interface of the AOT reverse micelle, which resulted in the partitioning of VA and H2O2, and by the changes of the conformation of LiP and the reactivity of the substrates.展开更多
The photophysical property of the tricarbocyanine dye IR144 has been extensively studied in non-aqueous solvents. However, as a potential near-infrared biomedical imaging probe, the photophysical property of IR144 in ...The photophysical property of the tricarbocyanine dye IR144 has been extensively studied in non-aqueous solvents. However, as a potential near-infrared biomedical imaging probe, the photophysical property of IR144 in water is still little known. So, the aggregation behaviors of IR144 in water with steady-state absorption spectroscopy and integrated polarization dependent femtosecond pump-probe spectroscopy were investigated. Through comparing the absorption spectral bandshape of IR144 in water and in water pool of AOT reverse micelles, It is found that IR144 form dimer aggregates in water even at very low concentration (〈 1.0× 10^- 7 moloL 1). And the absorption spectrum of the IR144 aggregates always displays a bimodal feature, which is independent of the dye concentration ranging from 1.0 × 10^-7 to 1.0 × 10^-4 mol·L^-1. For better understanding the aggregation behaviors of IR144 in water, we measured the ground state recovery kinetics and the reorientation kinetics of IR144 in water and in water pool of AOT reverse micelles (W0= [H2O]/[AOT], W0=40). It is found that the fluorescence quantum yield of 1R144 in water is lower than that in water pool of AOT reverse micelles, and the reorientation time of IR144 in water is slower than that in water pool of AOT reverse micelles. Those kinetic measurements also verify that IR144 exists as dimer aggregates in water.展开更多
The solubilization behavior of methyl orange as a solvation probe in multiple systems composed of super-critical carbon dioxide,surfactants and co-solvents,is studied.It is concluded that some surfactants,such as sodi...The solubilization behavior of methyl orange as a solvation probe in multiple systems composed of super-critical carbon dioxide,surfactants and co-solvents,is studied.It is concluded that some surfactants,such as sodium bis-(2-ethylhexyl)sulfosuccinate(AOT)and isooctyl phenol polyethoxylate(TX-10),could form reverse micelles in supercritical carbon dioxide under the action of butanol.The formation of reverse micelles is a spontaneous process thermodynamically.Specifically for the nonionic surfactant TX-10,the formation of reverse micelles is dependent on the entropy increase in the system,while for the anionic sur-factant AOT,the micellization is mainly dominated by the increase in enthalpy at higher temperatures,but by the increase in entropy at lower temperatures.展开更多
基金Funded by the National Natural Science Foundation of China (No. 60372002)
文摘Based on the study of a new type of conducting polymer poly (3,4-ethylenedioxythiophene) (PEDOT),we focussed on the preparation and characteristics of PEDOT nanoparticles made by reversed micelle method.Moreover,we deeply investigated the optical,electrical and the thermal stability of PEDOT nanoparticles.The main results are as follows: the small-sized PEDOT nanoparticles were prepared and utilized by different methods,such as ultraviolet/visible (UV-Vis) spectroscopy,Fourier-transform infrared (FT- IR) spectrum,scanning electron microscopy(SEM) and so on.The results show that the amount of oxidizer,ultrasonic treatment,polymerizing temperature and doping degree can influent morphology,electrical ability and gas sensitivity of PEDOT nanoparticles.The Bragg peaks of nanoparticles at 6.7°,12.7°,25° were observed by XRD and the better orientation of molecular chain was attributed to the effective doping of toluene-p-sulfonic acid,which also resulted in an enhancement of thermal stability of nanoparticles than conventional PEDOT.
文摘Hemeproteins encapsulated in reversed micelle formulated with di-2-ethylhexyl sulfosuccinate(AOT) was found to catalyze the polymerization of o-phenylenediamine(o-PDA) with hydrogen peroxide, whereas o-PDA catalyzed by hemeproteins dissolved in water could only form its trimers. As the nanostructural environment in reversed micelle acts as a certain orientation surrounding medium, it offers a strong electrostatic field that alters the reductive potential of Fe 3+/Fe 2+(E m7) in the heme of hemeproteins and thus increases the catalytic activity of peroxidase accordingly. According to the results of UV-Vis, 1H NMR and FTIR, the polymer catalyzed by hemoglobin(Hb) in reversed micelle was presumed to be constructed of lines and trapeziforms alternatively.
基金This study was supported by the National Natural Science Foundation of China(No.U21A20270 and 32202079)Postdoctoral Science and Technology Project of Henan,Grant No.HN2022046+2 种基金Science and Technology Project of Henan Province(232103810064)the Innovative Funds Plan of Henan University of Technology(2021ZKCJ03)the Key Scientific Research Projects of Colleges and Universities of Henan(23A550012).
文摘The liquid-liquid extraction method using reverse micelles can simultaneously extract lipid and protein of oilseeds,which have become increasingly popular in recent years.However,there are few studies on mass transfer processes and models,which are helpful to better control the extraction process of oils and proteins.In this paper,mass transfer process of peanut protein extracted by bis(2-ethylhexyl)sodium sulfosuccinate(AOT)/isooctane reverse micelles was investigated.The effects of stirring speed(0,70,140,and 210 r/min),temperature of extraction(30,35,40,45,and 50℃),peanut flour particle size(0.355,0.450,0.600,and 0.900 mm)and solidliquid ratio(0.010,0.0125,0.015,0.0175,and 0.020 g/mL)on extraction rate were examined.The results showed that extraction rate increased with temperature rising,particle size reduction as well as solid-liquid ratio increase respectively,while little effect of stirring speed(P>0.05)was observed.The apparent activation energy of extraction process was calculated as 10.02 kJ/mol and Arrhenius constant(A)was 1.91 by Arrhenius equation.There was a linear relationship between reaction rate constant and the square of the inverse of initial particle radius(1/r_(0)^(2))(P<0.05).This phenomenon and this shrinking core model were anastomosed.In brief,the extraction process was controlled by the diffusion of protein from the virgin zone interface of particle through the reacted zone and it was in line with the first order reaction.Mass transfer kinetics of peanut protein extracted by reverse micelles was established and it was verified by experimental results.The results provide an important theoretical guidance for industrial production of peanut protein separation and purification.
文摘The extraction of cytochrome C was carried out by means of phase transfer technique with three different reverse micellar systems, i.e. , a CTAB micellar solution in n butyl alcohol chloroform(volume ratio 4∶1), an AOT micellar solution in isooctane and a SDSS D 2EHPA micellar solution in isooctane. The extraction mechanisms were studied. The results show that the extraction mechanisms for the same proteins with different types of reverse micellar systems can be distinct. The extraction of cytochrome C with CTAB and SDSS D 2EHPA reverse micellar systems are carried out according to the mechanism of electrostatic interaction. However, in the extraction of cytochrome C with the AOT reverse micellar system, the electrostatic interaction between the protein and the surfactant is not important.
基金We thank the National Natural Science Foundation of China,the Ministry of Science and Technology of China(grant No.29971031,20073050,and G2000028204)for the financial support.
文摘Effect of dissolved CO2 on bovine serum albumin (BSA) solubilization in the reverse micelles of sodium bis (2-ethylhexyl) sulfosuccinate (AOT) in 2,2,4-trimethylpentane (iso-octane) has been studied at 308.2 K. It was found that BSA can be precipitated completely by CO2 while the AOT and water remain in the iso-octane continuous phase. This opens up a possibility for recovery of pure protein solids directly from reverse micellar solutions.
基金We thank the National Natural Science Foundation of China,the Ministry of ScienceTechnology of China(grant No.29971031,20073050,and G2000028204)for financial support.
文摘The interaction between amphiphilic porphyrin and phenothiazine in AOT/isooctane/ water reverse micelle was investigated by UV-Vis spectra. A new absorption complex between the two species is formed in such circumstances, which is ascribed to the enrichment of the components by the reverse micelle. The fluorescence quenching of CHTTP by PTH becomes more efficient after the formation of the absorption complex.
基金Support from the National Natural Science Foundation of China (20003001) the Special Fund of MEC (200020) and the Doctoral Program Foundation of MEC (2000000155) is gratefully acknowledged.
文摘Crystalline TiO2 nanoparticles were synthesized by hydrolysis of titanium tetrabutoxide in the presence of hydrochloric acid in NP-5 (Igepal CO-520)/ cyclohexane reverse micelle solution at room temperature. Pure rutile nanoparticles were obtained at an appropriate acid concentration. The influences of various reaction conditions such as the concentration of acids, water content value (w=[H2O]/[NP-5]) on the formation, crystal phase, morphology, and size of the TiO2 particles were investigated.
基金Supported by National Natural Science Foundation of China(21176058,31171790,21376064,31201293)Innovation Scientists and Technicians Troop Construction Projects of Zhengzhou City(ISTTCPZZC)
文摘The aim of this study was to detect the size changes of reverse micelles after extraction of peanut protein and their forward extraction rates. Factors that affect the size of reverse micelles and the extraction of peanut protein were also investigated. The size of reverse micelles and the size changes were measured according to the theory of dynamic light scattering under different conditions such as different sodium bis(2-ethylhexyl) sulfosuccinate(AOT) concentrations, p H values, ion concentrations, and salt species.With the increase of AOT surfactant concentrations in a certain range, the size of empty and full reverse micelles increased and the forward extraction rate decreased. The effect of pH on empty reverse micelles was not significant. However, the effect of pH on the full reverse micelle size and forward extraction rate were significant. Its forward extraction rate increased to the maximum39.6% at pH 7.5. The increase of the salt concentration of a buffer solution in a certain range decreased the size of empty and full reverse micelles and reduced the forward extraction rate of peanut protein. Ionic species had important effects on reverse micelles and peanut protein extraction. An increase in the amount of buffer solution enlarged the empty reverse micelle size in 0.03%-0.11%(V/V). However, it did not translate to a larger reverse micelle size. The size of the empty reverse micelles containing K_2SO_2 reached 24.1 nm with a 0.19%(V/V) buffer solution added. The sizes of the full reverse micelles were larger than those of the empty reverse micelles after forward extraction. However, maximum sizes were achieved with the addition of a 0.03%(V/V) buffer solution. The amount of 0.03%(V/V) buffer solution added was appropriate for extracting peanut protein.
基金supported by the National Natural Science Foundation of China(No.62175185)。
文摘The dynamics of water within a nanopool of a reverse micelle is heavily affected by the amphiphilic interface.In this work,the terahertz(THz)spectra of cyclohexane/Igepal/water nonionic reverse micelle mixture are measured by THz timedomain spectroscopy and analyzed with two Debye models and complex permittivity of background with volume ratios.Based on the fitted parameters of bulk and fast water,the molar concentration of all kinds of water molecules and hydration water molecule number per Igepal molecule are calculated.We find that slow hydration water has the highest proportion in water when the radius parameterω_(0)<10,while bulk water becomes the main component whenω_(0)≥10.The feature radius ratio of nonhydrated and hydrated water to total water nanopool is roughly obtained from 0.39 to 0.85 with increasingω_(0).
文摘The effects of postthermal treatment and irradiation time on the structure and thermal stability of TiO2/polyacrylate nanocomposites by a sol-gel process in reverse micelles and subsequent rapid photopolymerization were investigated, and the hybrid films were characterized by thermal gravimetry analysis (TGA), X-ray photoelectron spectrum (XPS), and atomic force microscopy (AFM). XPS data suggested that the prolongation of irradiation time and the postthermal treatment promoted titania formation, with the former affecting more remarkably. TGA data showed that TiO2-hybrid films could upgrade the decomposition onset temperature (Tonset) as well as the temperature at which there is a maximum mass loss rate (Tmax). AFM data demonstrated that the inorganic titania particles with a mean diameter of 25.26-28.84 nm were homogeneously distributed in the organic matrix.
基金This work was supported by the National Key Research and Development Program of China(No.2022YFE0107800)National Natural Science Foundation of China(Nos.82073332,and 81673022)。
文摘Orally administered peptides or proteins are garnering increasing preference owing to their superiority in terms of patient compliance and convenience.However,the development of oral protein formulations has stalled due to the low bioavailability of macromolecules that encounter the aggressive gastrointestinal environment and harsh mucus villi barrier.Herein,we propose an ideal reverse micelle/self-emulsifying drug delivery system(RM/SEDDS)nanoplatform that is capable of improving the oral bioavailability of hydrophilic peptides by preventing enzymatic degradation and enhancing mucosal permeability.Upon the passage through the mucus,the self-emulsifying drug delivery system with optimal surface properties effectively penetrates the viscoelastic mucosal barrier,followed by the exposure of the inner reverse micelle amphipathic vectors,which autonomously form continua with the lipidic cell membrane and facilitate the internalization of drugs.This membrane-fusion mechanism inaugurates a new way for hydrophilic peptide delivery in the free form,circumventing the traditional impediments of the cellular internalization of nanocarriers and subsequent poor release of drugs.And more importantly,reverse micelles are not spatially specific to the laden drugs,which enables their delivery for a myriad of peptide clinical drugs.In conclusion,as an exquisitely designed nanoplatform,RM/SEDDS overcomes multiple physiological barriers and opens a new path for drug cellular entry,providing new prospects for the development of oral drug delivery systems.
文摘Gold nanoparticles with size 3-10 nm (diameter) were prepared by thereduction of HAuCl_4 in a CTAB/octane + 1-butanol/H_2O reverse micelle system using NaBH_4 as thereducing agent. The as-formed gold nanoparticle colloid was characterized by UV/vis absorptionspectrum and transmission electron microscopy (TEM). Various capping ligands, such as alkyl-thiolswith different chain length and shape, trioctylphosphine (TOP), and pyridine are used to passivatethe gold nanoparticles for the purpose of self-organization into superstructures. It is shown thatthe ligands have a great influence on the self-organization of gold nanoparticles intosuper-lattices, and do-decanethiol C_(12)H_(25)SH is confirmed to be the best ligand for theserf-organization. Self-organization of C_(12)H_(25)SH-capped gold nanoparticles into 1D, 2D and 3Dsuperlattices has been observed on the carbon-coated copper grid by TEM without using any selectiveprecipitation process.
基金Project supportedby the Natural Science Founciation of Shandong Province (No. 65310044) and the National Natural Science Foundation of China (No. 30570014).
文摘The steady state kinetics of the lignin peroxidase (LIP) catalyzed oxidation of veratryl alcohol (VA) by H2O2 in a sodium bis(2-ethylhexyl) sulfosuccinate (AOT)/isooctane/toluene/water reverse micellar medium was studied and a comparison with the corresponding aqueous medium was made to understand the effect of the reverse micellar medium on the catalytic mechanism and kinetic parameters. Results indicated that the model reaction in the AOT reverse micelle followed the ping-pong mechanism with true kcat, Km,VA and KmH2O2 being 59.6min^-1, 13.9 mmol· L^-1 and 94.8 μmol·L^-1, respectively; inhibition of high level of H2O2 on LiP followed the reversible competitive pattern with Ki being 0.140 mmol·L^-1. The reaction mechanism and inhibition pattern in the AOT reverse micellar medium were the same as those in bulk aqueous medium, but the kinetic parameters except KmH2O2 were greatly different in the two media. The kcat and Ki values in the reverse micelle were approximately 2 and 20 times smaller than the corresponding values in the aqueous solution, but the Michaelis constant of VA was approximately 100 times greater than that in the aqueous solution. The above mentioned differences in the kinetic parameters were caused by the microheterogeneity and the interface of the AOT reverse micelle, which resulted in the partitioning of VA and H2O2, and by the changes of the conformation of LiP and the reactivity of the substrates.
基金Project supported by the National Natural Science Foundation of China (Nos. 20603047, 20733001) and Renmin University of China.
文摘The photophysical property of the tricarbocyanine dye IR144 has been extensively studied in non-aqueous solvents. However, as a potential near-infrared biomedical imaging probe, the photophysical property of IR144 in water is still little known. So, the aggregation behaviors of IR144 in water with steady-state absorption spectroscopy and integrated polarization dependent femtosecond pump-probe spectroscopy were investigated. Through comparing the absorption spectral bandshape of IR144 in water and in water pool of AOT reverse micelles, It is found that IR144 form dimer aggregates in water even at very low concentration (〈 1.0× 10^- 7 moloL 1). And the absorption spectrum of the IR144 aggregates always displays a bimodal feature, which is independent of the dye concentration ranging from 1.0 × 10^-7 to 1.0 × 10^-4 mol·L^-1. For better understanding the aggregation behaviors of IR144 in water, we measured the ground state recovery kinetics and the reorientation kinetics of IR144 in water and in water pool of AOT reverse micelles (W0= [H2O]/[AOT], W0=40). It is found that the fluorescence quantum yield of 1R144 in water is lower than that in water pool of AOT reverse micelles, and the reorientation time of IR144 in water is slower than that in water pool of AOT reverse micelles. Those kinetic measurements also verify that IR144 exists as dimer aggregates in water.
基金supported by the National Natural Science Foundation of China(Grant No.20606013)China Postdoctoral Science Foundation(Grant No.2005037584).
文摘The solubilization behavior of methyl orange as a solvation probe in multiple systems composed of super-critical carbon dioxide,surfactants and co-solvents,is studied.It is concluded that some surfactants,such as sodium bis-(2-ethylhexyl)sulfosuccinate(AOT)and isooctyl phenol polyethoxylate(TX-10),could form reverse micelles in supercritical carbon dioxide under the action of butanol.The formation of reverse micelles is a spontaneous process thermodynamically.Specifically for the nonionic surfactant TX-10,the formation of reverse micelles is dependent on the entropy increase in the system,while for the anionic sur-factant AOT,the micellization is mainly dominated by the increase in enthalpy at higher temperatures,but by the increase in entropy at lower temperatures.