Carboxyl methyl cellulose （CMC） was mixed into mortar to improve the waterretention performance of mortar, the quality of floated coat of aerated concrete became better. The consistency and compression strength of m...Carboxyl methyl cellulose （CMC） was mixed into mortar to improve the waterretention performance of mortar, the quality of floated coat of aerated concrete became better. The consistency and compression strength of mortar with CMC were studied. The water absorption was studied with the method of filter paper. The micro mechanism was researched with X-ray diffraction and scanning electron microscopy（SEM）. The experimental results show the water-holding performance of mortar with CMC is largely improved and it is better when the mixed amount is about 1.5%; the compression strength had a descending trend with the increase of CMC; CMC reacted with calcium hydroxide（CH） into the deposition of calcium carboxyl methyl cellulose.展开更多
It was tried to develop the preparation method for microencapsulating the uycalyptus oil containing fine aqueous droplets by using the interfacial condensation reaction between hydroxyl propyl methyl cellulose and tan...It was tried to develop the preparation method for microencapsulating the uycalyptus oil containing fine aqueous droplets by using the interfacial condensation reaction between hydroxyl propyl methyl cellulose and tannic acid. Uycalyptus oil containing fine aqueous droplets was dispersed in the continuous water phase to form the (W/O)/W emulsion. Tannic acid and hydroxyl propyl methyl cellulose were dissolved in the inner aqueous droplets and in the outer continuous water phase, respectively. Tannic acid transferred through the oil phase from the inner water droplets to the interface between the oil phase and the continuous water phase and then, reacted with hydroxyl propyl methyl cellulose. In the experiment, the concentrations of hydroxyl propyl methyl cellulose and tannic acid were mainly changed stepwise. The uycalyptus oil containing the fine water droplets could be microencapsulated satisfactorily. It was found that the microcapsules were composed of the gelated hydroxyl propyl methyl cellulose film as the shell, the fine aqueous droplets as the first core and the oil droplet as the second core.展开更多
The surface of nano-TiO_2 was encapsulated with hydroxyl-propyl-methyl cellulose(HPMC),and then cograftedwith acrylates.Conditions of absorbing and grafting have been studied.Modified nano-TiO_2 particles were charact...The surface of nano-TiO_2 was encapsulated with hydroxyl-propyl-methyl cellulose(HPMC),and then cograftedwith acrylates.Conditions of absorbing and grafting have been studied.Modified nano-TiO_2 particles were characterized byFT-IR spectra,TEM and TG analysis.It was convinced from FT-IR studies that both methyl methacrylate(MMA)and butyl-methacrylate(BMA)were co-grafted onto the surface of nano-TiO_2 particles.TEM images show that the surface of nano-TiO_2 particles was successfully modified by a thick layer of film-like polymer.TG results demonstrate that the decompositiontemperature of HPMC-g-PMMA/PBMA,which has been grafted onto the surface of nano-TiO_2,is 56.9 K higher than that ofHPMC-g-PMMA/PBMA.展开更多
Objective:The objective of the present study was to develop floating microspheres of Cefpodoxime Proxetil in order to achieve an extended retention in the upper GIT,which may result in enhanced absorption and there by...Objective:The objective of the present study was to develop floating microspheres of Cefpodoxime Proxetil in order to achieve an extended retention in the upper GIT,which may result in enhanced absorption and there by improved bioavailability.Methods:The microspheres were prepared by non - aqueous solvent evaporation method using polymers such as Hydroxyl Propyl Methyl Cellulose（HPMC K15M）,Ethyl Cellulose（EC） in different ratios,and Cefpodoxime Proxetil contain in each formulation.In vitro drug release were performed by USP apparatus type I andthe microspheres were characterized by calculating percentage yield,particle size analysis, buoyancy percentage,drug entrapment efficiencyand in vitro drug release studies.Results:The result showed microspheres yield were 50.50%-72.21%,particle size were distributed between75-600μm,drug entrapment efficiency were 14.1%-28.2%,buoyancy percentage were 70.10%-88.25%.Conclusion: Cefpodoxime Proxetil floating microspheres,at the lower polymer to drug ratio,there was a significant drug release. The better drug release profile was seen with FA<sub>2</sub> with ratio of drug polymer（1:2）.展开更多
文摘Carboxyl methyl cellulose （CMC） was mixed into mortar to improve the waterretention performance of mortar, the quality of floated coat of aerated concrete became better. The consistency and compression strength of mortar with CMC were studied. The water absorption was studied with the method of filter paper. The micro mechanism was researched with X-ray diffraction and scanning electron microscopy（SEM）. The experimental results show the water-holding performance of mortar with CMC is largely improved and it is better when the mixed amount is about 1.5%; the compression strength had a descending trend with the increase of CMC; CMC reacted with calcium hydroxide（CH） into the deposition of calcium carboxyl methyl cellulose.
文摘It was tried to develop the preparation method for microencapsulating the uycalyptus oil containing fine aqueous droplets by using the interfacial condensation reaction between hydroxyl propyl methyl cellulose and tannic acid. Uycalyptus oil containing fine aqueous droplets was dispersed in the continuous water phase to form the (W/O)/W emulsion. Tannic acid and hydroxyl propyl methyl cellulose were dissolved in the inner aqueous droplets and in the outer continuous water phase, respectively. Tannic acid transferred through the oil phase from the inner water droplets to the interface between the oil phase and the continuous water phase and then, reacted with hydroxyl propyl methyl cellulose. In the experiment, the concentrations of hydroxyl propyl methyl cellulose and tannic acid were mainly changed stepwise. The uycalyptus oil containing the fine water droplets could be microencapsulated satisfactorily. It was found that the microcapsules were composed of the gelated hydroxyl propyl methyl cellulose film as the shell, the fine aqueous droplets as the first core and the oil droplet as the second core.
基金This work was funded by the Natural Science Fund of Anhui Educational Committeethe Youth Fund of Anhui Normal University.
文摘The surface of nano-TiO_2 was encapsulated with hydroxyl-propyl-methyl cellulose(HPMC),and then cograftedwith acrylates.Conditions of absorbing and grafting have been studied.Modified nano-TiO_2 particles were characterized byFT-IR spectra,TEM and TG analysis.It was convinced from FT-IR studies that both methyl methacrylate(MMA)and butyl-methacrylate(BMA)were co-grafted onto the surface of nano-TiO_2 particles.TEM images show that the surface of nano-TiO_2 particles was successfully modified by a thick layer of film-like polymer.TG results demonstrate that the decompositiontemperature of HPMC-g-PMMA/PBMA,which has been grafted onto the surface of nano-TiO_2,is 56.9 K higher than that ofHPMC-g-PMMA/PBMA.
文摘Objective:The objective of the present study was to develop floating microspheres of Cefpodoxime Proxetil in order to achieve an extended retention in the upper GIT,which may result in enhanced absorption and there by improved bioavailability.Methods:The microspheres were prepared by non - aqueous solvent evaporation method using polymers such as Hydroxyl Propyl Methyl Cellulose（HPMC K15M）,Ethyl Cellulose（EC） in different ratios,and Cefpodoxime Proxetil contain in each formulation.In vitro drug release were performed by USP apparatus type I andthe microspheres were characterized by calculating percentage yield,particle size analysis, buoyancy percentage,drug entrapment efficiencyand in vitro drug release studies.Results:The result showed microspheres yield were 50.50%-72.21%,particle size were distributed between75-600μm,drug entrapment efficiency were 14.1%-28.2%,buoyancy percentage were 70.10%-88.25%.Conclusion: Cefpodoxime Proxetil floating microspheres,at the lower polymer to drug ratio,there was a significant drug release. The better drug release profile was seen with FA<sub>2</sub> with ratio of drug polymer（1:2）.
