To improve the oxidative stability and application of fish oil, it was microencapsulated by simple coacervation followed by spray drying. Simple coacervation took place by adding malt dextrin into the emulsion of fish...To improve the oxidative stability and application of fish oil, it was microencapsulated by simple coacervation followed by spray drying. Simple coacervation took place by adding malt dextrin into the emulsion of fish oil and hydroxypropyl methylcellulose （HPMC） solution. Influences of several process parameters on the microencapsulation were evaluated and the oxidative stability and microstructure of microcapsules were analyzed. Results showed that the coacervation could be observed only when dextrose equivalent value （DE value） of malt dextrin, concentration of HPMC solution and fish oil percentage in microcapsules were no more than 20. 5% and 40%, respectively. Moreover, microencapsulation efficiency was higher at HPMC solution concentration of 4% and fish oil percentage of less than 30%. The oxidative stability of fish oil was improved by the microencapsulation and done best in the ease of replacing malt dextrin by 40% with acacia. Scanning electronic microscopic photographs showed that the microcapsule obtained was a round, smooth and hollow microcapsule with its wall made up of innumerable small and solid submicrocapsules with the core of fish oil.展开更多
Hydroxypropyl xanthan gum(HXG) was prepared from xanthan gum(XG) and propylene oxide under alkaline condition. Rheological and drag reduction properties of different concentrations of aqueous HXG and XG solution were ...Hydroxypropyl xanthan gum(HXG) was prepared from xanthan gum(XG) and propylene oxide under alkaline condition. Rheological and drag reduction properties of different concentrations of aqueous HXG and XG solution were studied. The micro-structure network of HXG and XG solutions was investigated by Cryo-FESEM. The results showed that HXG and XG solutions could exhibit shear thinning property. The apparent viscosity of6 g·L-1HXG solution was 1.25 times more than that of 6 g·L-1XG solution. The storage modulus G′ and the loss modulus G″ of HXG solutions were greater than those of XG solutions, and thixotropic and viscoelastic properties were more significant in HXG solutions. The HXG and XG solutions reduced the pressure drop of straight pipe, and the maximum drag reduction of 1 g·L-1HXG and XG in smooth tube reached 72.8% and 68.1%, respectively. Drag reduction rate was increased as the concentration increased. The HXG solution may become a new polymeric drag reducer.展开更多
Polymers and polymeric composites have steadily reflected their importance in our daily life. Blending poly(vinyl alcohol) (PVA) with a potentially useful natural biopolymers such as hydroxypropyl cellulose (HPC) seem...Polymers and polymeric composites have steadily reflected their importance in our daily life. Blending poly(vinyl alcohol) (PVA) with a potentially useful natural biopolymers such as hydroxypropyl cellulose (HPC) seems to be an interesting way of preparing a polymeric blends. In the present work, blends of PVA/HPC of compositions (100/0, 90/10, 75/25, 50/50, 25/75, and 0/100 wt/wt%) were prepared to be used as bioequivalent materials. Thermal analyses [differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA)], and X-ray diffraction (XRD) were employed to characterize and reveal the miscibility map and the structural properties of such blend system. The obtained results of the thermal analyses showed variations in the glass transition temperature (Tg) indicating the miscibility of the blend systems. Moreover, the changes in the melting temperature (Tm), shape and area were attributed to the different degrees of crystallinity and the existence of polymer-polymer interactions between PVA and HPC molecules. The X-ray diffraction (XRD) analysis showed broadening and sharpening of peaks at different HPC concentrations with PVA. This indicated changes in the crystallinity/amorphosity ratio, and also suggested that the miscibility between the amorphous components of homo-polymers PVA and HPC is possible. The results showed that HPC doped in PVA film can improve the thermal stability of the film under investigation, leading to interesting technological applications.展开更多
Hydroxypropyl chitosan(HP-chitosan) has been shown to have promising applications in a wide range of areas due to its biocompatibility, biodegradability and various biological activities, especially in the biomedical ...Hydroxypropyl chitosan(HP-chitosan) has been shown to have promising applications in a wide range of areas due to its biocompatibility, biodegradability and various biological activities, especially in the biomedical and pharmaceutical fields. However, it is not yet known about its pharmacokinetics and biodegradation performance, which are crucial for its clinical applications. In order to lay a foundation for its further applications and exploitations, here we carried out fluorescence intensity and GPC analyses to determine the pharmacokinetics mode of fluorescein isothiocyanate-labeled HP-chitosan(FITC-HP-chitosan) and its biodegradability. The results showed that after intraperitoneal administration at a dose of 10 mg per rat, FITC-HP-chitosan could be absorbed rapidly and distributed to liver, kidney and spleen through blood. It was indicated that FITC-HP-chitosan could be utilized effectively, and 88.47% of the FITC-HP-chitosan could be excreted by urine within 11 days with a molecular weight less than 10 k Da. Moreover, our data indicated that there was an obvious degradation process occurred in liver(< 10 k Da at 24 h). In summary, HP-chitosan has excellent bioavailability and biodegradability, suggesting the potential applications of hydroxypropyl-modified chitosan as materials in drug delivery, tissue engineering and biomedical area.展开更多
Hydration heat effect of cement pastes and mechanism of hydroxypropyl methyl cellulose ether （HPMC） and expanded perlite in cement pastes were studied by means of hydration exothermic rate, hydration heat amount, FT...Hydration heat effect of cement pastes and mechanism of hydroxypropyl methyl cellulose ether （HPMC） and expanded perlite in cement pastes were studied by means of hydration exothermic rate, hydration heat amount, FTIR and TG-DTG. The results show that HPMC can significantly delay the hydration induction period and acceleration period of cement pastes. As mixing amount increased, hydration induction period of cement pastes enlarged and accelerated period gradually went back. At the same time, the amount of hydration heat gradually decreased. Expanded perlite had worse delay effects and less change of hydration heat amount of cement pastes than HPMC. HPMC changed the structure of C-S-H during cement hydration. The more amount of HPMC, the more obvious effect. However, EXP had little influence on the structure of C-S-H. At the same age, the content of Ca （OH）2 in cement pastes gradually decreased as the mixing amount increase of HPMC and expanded perlite, and had better delay effect than that single-doped with HPMC or expanded perlite when HPMC and expanded nerlite were both dooed in cement pastes.展开更多
Hydroxypropyl methyl cellulose(HPMC)-based hybrid nanocomposites reinforced with bacterial cellulose nanocrystals(BCNC) were prepared and characterized.The HPMC nanocomposites exhibited good thermal stability,with a t...Hydroxypropyl methyl cellulose(HPMC)-based hybrid nanocomposites reinforced with bacterial cellulose nanocrystals(BCNC) were prepared and characterized.The HPMC nanocomposites exhibited good thermal stability,with a thermogravimetric peak temperature of around 346℃.The addition of BCNC did not significantly affect the thermal degradation temperature or improve the transparency of HPMC nanocomposites.However,the addition of BCNC favorably affected the light scattering properties of the nanocomposites and enhanced mechanical properties such as tensile stress and Young's modulus from 65 MPa and 1.5 GPa up to 139 MPa and 3.2 GPa,respectively.The oxygen permeability of the HPMC nanocomposites also increased with increase in the amount of BCNC added.展开更多
[Objectives]To enhance the skin permeability of hydroxypropyl tetrahydropyrantriol and provide a reference for the subsequent prevention or treatment of skin aging.[Methods]The lyophilization process of hydroxypropyl ...[Objectives]To enhance the skin permeability of hydroxypropyl tetrahydropyrantriol and provide a reference for the subsequent prevention or treatment of skin aging.[Methods]The lyophilization process of hydroxypropyl tetrahydropyrantriol liposomes was investigated using a single factor method,and a quality evaluation system was established based on the appearance,particle size,PDI,and re-dispersibility of the lyophilized samples.[Results]The lyophilization process of hydroxypropyl tetrahydropyrantriol liposomes was determined by single factor experiments.The pre-freezing period was 16 h at-80℃,the total drying time was 36 h,and the addition of 10%mannitol-sucrose was used as the lyoprotectant.[Conclusions]The product prepared by the lyophilization method exhibits a fluffy and full appearance,with minimal shrinkage and collapse.The volume remains consistent before and after lyophilization,and the re-dispersibility is satisfactory.The re-dissolution process is rapid,and the particle size and polydispersity index(PDI)remain largely unchanged before and after lyophilization.展开更多
基金Project supported by the Doctoral Foundation of Guangdong Natural Science Foundation （No. 04300744）.
文摘To improve the oxidative stability and application of fish oil, it was microencapsulated by simple coacervation followed by spray drying. Simple coacervation took place by adding malt dextrin into the emulsion of fish oil and hydroxypropyl methylcellulose （HPMC） solution. Influences of several process parameters on the microencapsulation were evaluated and the oxidative stability and microstructure of microcapsules were analyzed. Results showed that the coacervation could be observed only when dextrose equivalent value （DE value） of malt dextrin, concentration of HPMC solution and fish oil percentage in microcapsules were no more than 20. 5% and 40%, respectively. Moreover, microencapsulation efficiency was higher at HPMC solution concentration of 4% and fish oil percentage of less than 30%. The oxidative stability of fish oil was improved by the microencapsulation and done best in the ease of replacing malt dextrin by 40% with acacia. Scanning electronic microscopic photographs showed that the microcapsule obtained was a round, smooth and hollow microcapsule with its wall made up of innumerable small and solid submicrocapsules with the core of fish oil.
基金Supported by the National High Technology Research and Development Program of China(2013AA064801)
文摘Hydroxypropyl xanthan gum(HXG) was prepared from xanthan gum(XG) and propylene oxide under alkaline condition. Rheological and drag reduction properties of different concentrations of aqueous HXG and XG solution were studied. The micro-structure network of HXG and XG solutions was investigated by Cryo-FESEM. The results showed that HXG and XG solutions could exhibit shear thinning property. The apparent viscosity of6 g·L-1HXG solution was 1.25 times more than that of 6 g·L-1XG solution. The storage modulus G′ and the loss modulus G″ of HXG solutions were greater than those of XG solutions, and thixotropic and viscoelastic properties were more significant in HXG solutions. The HXG and XG solutions reduced the pressure drop of straight pipe, and the maximum drag reduction of 1 g·L-1HXG and XG in smooth tube reached 72.8% and 68.1%, respectively. Drag reduction rate was increased as the concentration increased. The HXG solution may become a new polymeric drag reducer.
文摘Polymers and polymeric composites have steadily reflected their importance in our daily life. Blending poly(vinyl alcohol) (PVA) with a potentially useful natural biopolymers such as hydroxypropyl cellulose (HPC) seems to be an interesting way of preparing a polymeric blends. In the present work, blends of PVA/HPC of compositions (100/0, 90/10, 75/25, 50/50, 25/75, and 0/100 wt/wt%) were prepared to be used as bioequivalent materials. Thermal analyses [differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA)], and X-ray diffraction (XRD) were employed to characterize and reveal the miscibility map and the structural properties of such blend system. The obtained results of the thermal analyses showed variations in the glass transition temperature (Tg) indicating the miscibility of the blend systems. Moreover, the changes in the melting temperature (Tm), shape and area were attributed to the different degrees of crystallinity and the existence of polymer-polymer interactions between PVA and HPC molecules. The X-ray diffraction (XRD) analysis showed broadening and sharpening of peaks at different HPC concentrations with PVA. This indicated changes in the crystallinity/amorphosity ratio, and also suggested that the miscibility between the amorphous components of homo-polymers PVA and HPC is possible. The results showed that HPC doped in PVA film can improve the thermal stability of the film under investigation, leading to interesting technological applications.
基金financially supported by National High Technology Research and Development Program of China(863 Program,Grant No.2007AA091603)
文摘Hydroxypropyl chitosan(HP-chitosan) has been shown to have promising applications in a wide range of areas due to its biocompatibility, biodegradability and various biological activities, especially in the biomedical and pharmaceutical fields. However, it is not yet known about its pharmacokinetics and biodegradation performance, which are crucial for its clinical applications. In order to lay a foundation for its further applications and exploitations, here we carried out fluorescence intensity and GPC analyses to determine the pharmacokinetics mode of fluorescein isothiocyanate-labeled HP-chitosan(FITC-HP-chitosan) and its biodegradability. The results showed that after intraperitoneal administration at a dose of 10 mg per rat, FITC-HP-chitosan could be absorbed rapidly and distributed to liver, kidney and spleen through blood. It was indicated that FITC-HP-chitosan could be utilized effectively, and 88.47% of the FITC-HP-chitosan could be excreted by urine within 11 days with a molecular weight less than 10 k Da. Moreover, our data indicated that there was an obvious degradation process occurred in liver(< 10 k Da at 24 h). In summary, HP-chitosan has excellent bioavailability and biodegradability, suggesting the potential applications of hydroxypropyl-modified chitosan as materials in drug delivery, tissue engineering and biomedical area.
基金Funded by the National Natural Science Foundation of China(No.50902107)National Science and Technology Supporting Program (No.2011BAJ04B02)the Fundamental Research Funds for the Central Universities (No.2011-YB-03)
文摘Hydration heat effect of cement pastes and mechanism of hydroxypropyl methyl cellulose ether （HPMC） and expanded perlite in cement pastes were studied by means of hydration exothermic rate, hydration heat amount, FTIR and TG-DTG. The results show that HPMC can significantly delay the hydration induction period and acceleration period of cement pastes. As mixing amount increased, hydration induction period of cement pastes enlarged and accelerated period gradually went back. At the same time, the amount of hydration heat gradually decreased. Expanded perlite had worse delay effects and less change of hydration heat amount of cement pastes than HPMC. HPMC changed the structure of C-S-H during cement hydration. The more amount of HPMC, the more obvious effect. However, EXP had little influence on the structure of C-S-H. At the same age, the content of Ca （OH）2 in cement pastes gradually decreased as the mixing amount increase of HPMC and expanded perlite, and had better delay effect than that single-doped with HPMC or expanded perlite when HPMC and expanded nerlite were both dooed in cement pastes.
基金financially supported by the GuangdongHong Kong joint innovation program(2014B050505019)the National Natural Science Foundation of China(31570569)
文摘Hydroxypropyl methyl cellulose(HPMC)-based hybrid nanocomposites reinforced with bacterial cellulose nanocrystals(BCNC) were prepared and characterized.The HPMC nanocomposites exhibited good thermal stability,with a thermogravimetric peak temperature of around 346℃.The addition of BCNC did not significantly affect the thermal degradation temperature or improve the transparency of HPMC nanocomposites.However,the addition of BCNC favorably affected the light scattering properties of the nanocomposites and enhanced mechanical properties such as tensile stress and Young's modulus from 65 MPa and 1.5 GPa up to 139 MPa and 3.2 GPa,respectively.The oxygen permeability of the HPMC nanocomposites also increased with increase in the amount of BCNC added.
基金Youth Science Foundation Project of Sichuan Provincial Department of Science and Technology(2022NSFSC1437)Special Project of Scientific and Technological Research of Sichuan Provincial Administration of Traditional Chinese Medicine(2021MS121)Fundamental Research Funds for the Central Universities of Southwest Minzu University(ZYN2022040).
文摘[Objectives]To enhance the skin permeability of hydroxypropyl tetrahydropyrantriol and provide a reference for the subsequent prevention or treatment of skin aging.[Methods]The lyophilization process of hydroxypropyl tetrahydropyrantriol liposomes was investigated using a single factor method,and a quality evaluation system was established based on the appearance,particle size,PDI,and re-dispersibility of the lyophilized samples.[Results]The lyophilization process of hydroxypropyl tetrahydropyrantriol liposomes was determined by single factor experiments.The pre-freezing period was 16 h at-80℃,the total drying time was 36 h,and the addition of 10%mannitol-sucrose was used as the lyoprotectant.[Conclusions]The product prepared by the lyophilization method exhibits a fluffy and full appearance,with minimal shrinkage and collapse.The volume remains consistent before and after lyophilization,and the re-dispersibility is satisfactory.The re-dissolution process is rapid,and the particle size and polydispersity index(PDI)remain largely unchanged before and after lyophilization.
