Hydrophobically modified poly(4-vinyl pyridines) by alkyl bromides are kinds of polysoap similar to the surfactant. Properties of dilute solutions were studied through the viscosity measurements in pure water and NaCl...Hydrophobically modified poly(4-vinyl pyridines) by alkyl bromides are kinds of polysoap similar to the surfactant. Properties of dilute solutions were studied through the viscosity measurements in pure water and NaCl solutions. In aqueous solutions of polysoaps hydrophobic interaction can be attributed to aggregation of hydrophobic groups of the polysoap main chains. The hydrophobic groups of polysoap can aggregate to form hydrophobic microdomains (micelles) in aqueous solution. This is a compact conformation. The formation of such microdomains is a process of dynamic equilibrium.展开更多
Epichlorohydrin (ECH) and tetraethylenepentamine(TEPA) were copolymerized andthe copolymers were modified hydrophobically using a pendant C18 hydrophobic group (HPTE).Hydrophobic interaction of modified polymer was in...Epichlorohydrin (ECH) and tetraethylenepentamine(TEPA) were copolymerized andthe copolymers were modified hydrophobically using a pendant C18 hydrophobic group (HPTE).Hydrophobic interaction of modified polymer was investigated by fluorescence using pyrene as aprobe. It reveals that hydrophobic microdomains are formed by aggregation of hydrophobic sidechains. The water in hydrophobic microdomains is in a state of diffusion equilibrium under thehydrophobic interaction. Critical aggregate concentration (ccac) of HPTE decreases with increas-ing content of the bound hydrophobic groups.展开更多
The objective of the work involves the synthesis of comb-like amphiphilic cationic polymers with repeating units methacylamides laterally substituted by a group containing a quaternary ammonium site and a hydrophobic ...The objective of the work involves the synthesis of comb-like amphiphilic cationic polymers with repeating units methacylamides laterally substituted by a group containing a quaternary ammonium site and a hydrophobic n-alkyl side chain with 8-10 carbon atoms. Two synthesis methods were developed successfully. The first method is consisted to synthesizing first amphiphilic cationic methacrylamide monomers. In the second method the tertiary amine groups of polymers precursors were quaternised with various n-alkyl bromides. All the polymers obtained in this way were characterized by spectroscopic methods: 1^H NMR and by viscometry. The reduced viscosity of hydro-alcoholic polymer solution decreases with polymer concentration. Viscometry study showed that these polymers display typical polysoap behavior in hydro-alcoholic mixtures.展开更多
A novel type of polysoap hydrogel based on poly(tetraethylenepentamine-epichlorohydrin)hydrophobically modified by stearic acid was prepared. The deswelling behaviors of polysoap hydrogels werestudied by immersing the...A novel type of polysoap hydrogel based on poly(tetraethylenepentamine-epichlorohydrin)hydrophobically modified by stearic acid was prepared. The deswelling behaviors of polysoap hydrogels werestudied by immersing the gels in buffer solution at various pHs and ionic species. The deswelling of the gelsdid not depend on the cationic species of electrolyte but depended strongly on the anionic species. Acomparison of polysoap gels with the gel unmodified hydrophobically verified the importance of hydrophobicinteraction, which enhances the occurrence of deswelling rate.展开更多
基金The project is financially supported by National Natural Science Foundation of China.
文摘Hydrophobically modified poly(4-vinyl pyridines) by alkyl bromides are kinds of polysoap similar to the surfactant. Properties of dilute solutions were studied through the viscosity measurements in pure water and NaCl solutions. In aqueous solutions of polysoaps hydrophobic interaction can be attributed to aggregation of hydrophobic groups of the polysoap main chains. The hydrophobic groups of polysoap can aggregate to form hydrophobic microdomains (micelles) in aqueous solution. This is a compact conformation. The formation of such microdomains is a process of dynamic equilibrium.
文摘Epichlorohydrin (ECH) and tetraethylenepentamine(TEPA) were copolymerized andthe copolymers were modified hydrophobically using a pendant C18 hydrophobic group (HPTE).Hydrophobic interaction of modified polymer was investigated by fluorescence using pyrene as aprobe. It reveals that hydrophobic microdomains are formed by aggregation of hydrophobic sidechains. The water in hydrophobic microdomains is in a state of diffusion equilibrium under thehydrophobic interaction. Critical aggregate concentration (ccac) of HPTE decreases with increas-ing content of the bound hydrophobic groups.
文摘The objective of the work involves the synthesis of comb-like amphiphilic cationic polymers with repeating units methacylamides laterally substituted by a group containing a quaternary ammonium site and a hydrophobic n-alkyl side chain with 8-10 carbon atoms. Two synthesis methods were developed successfully. The first method is consisted to synthesizing first amphiphilic cationic methacrylamide monomers. In the second method the tertiary amine groups of polymers precursors were quaternised with various n-alkyl bromides. All the polymers obtained in this way were characterized by spectroscopic methods: 1^H NMR and by viscometry. The reduced viscosity of hydro-alcoholic polymer solution decreases with polymer concentration. Viscometry study showed that these polymers display typical polysoap behavior in hydro-alcoholic mixtures.
基金This work is financially supported by National Natural Science Foundation of China.
文摘A novel type of polysoap hydrogel based on poly(tetraethylenepentamine-epichlorohydrin)hydrophobically modified by stearic acid was prepared. The deswelling behaviors of polysoap hydrogels werestudied by immersing the gels in buffer solution at various pHs and ionic species. The deswelling of the gelsdid not depend on the cationic species of electrolyte but depended strongly on the anionic species. Acomparison of polysoap gels with the gel unmodified hydrophobically verified the importance of hydrophobicinteraction, which enhances the occurrence of deswelling rate.