In this study,the effects of surfactants on the hydrodynamic characteristics of bubbles in shear-thinning fluids at low Reynolds number(Re<50)are investigated.The bubble terminal velocity and drag coefficient of bu...In this study,the effects of surfactants on the hydrodynamic characteristics of bubbles in shear-thinning fluids at low Reynolds number(Re<50)are investigated.The bubble terminal velocity and drag coefficient of bubble in clean and contaminated carboxymethylcellulose(CMC)solutions are obtained using a high-speed camera for examining differences.The results show that the existence of surfactant could reduce the terminal velocity of bubble at small volume(0.25wt%CMC:<100 mm3;0.50wt%CMC:<110 mm3),attributed to stiffening the bubble interface.However,this negative effect decreases and finally disappears with increasing bubble volume.The drag coefficient curves of the bubble in contaminated CMC solution exhibit behavior similar to that exhibited by a solid sphere at Re<10,indicating that internal circulation flow is absent at the bubble interface as compared to that in clean CMC solution.However,for 10<Re<40,a transition of drag curve from 24/Re to 16/Re in contaminated CMC solution is observed,which is easy at low SDS concentrations and high CMC concentrations.展开更多
A novel surface active monomer （surfmer） containing poly（ethylene glycol） chain and terminated phosphate group was synthesized. The copolymerization of synthesized surfmer with NVP （N-vinylpyrrolidone） and with ...A novel surface active monomer （surfmer） containing poly（ethylene glycol） chain and terminated phosphate group was synthesized. The copolymerization of synthesized surfmer with NVP （N-vinylpyrrolidone） and with NVP and VEP （5-tert-butylperoxy-5-methyl-2-hexene-3-yne monomer） led to formation of corresponding surface-active copolymers. The capability of application of resulted copolymers as surface active macroinitiators of emulsion polymerization of styrene and as components of polymeric scaffolds was investigated.展开更多
基金Project(21406141)supported by the National Natural Science Foundation of ChinaProject(20141078)supported by the National Basic Research Program,ChinaProject(L201733)supported by the Research Foundation of Education Bureau of Liaoning Province,China
文摘In this study,the effects of surfactants on the hydrodynamic characteristics of bubbles in shear-thinning fluids at low Reynolds number(Re<50)are investigated.The bubble terminal velocity and drag coefficient of bubble in clean and contaminated carboxymethylcellulose(CMC)solutions are obtained using a high-speed camera for examining differences.The results show that the existence of surfactant could reduce the terminal velocity of bubble at small volume(0.25wt%CMC:<100 mm3;0.50wt%CMC:<110 mm3),attributed to stiffening the bubble interface.However,this negative effect decreases and finally disappears with increasing bubble volume.The drag coefficient curves of the bubble in contaminated CMC solution exhibit behavior similar to that exhibited by a solid sphere at Re<10,indicating that internal circulation flow is absent at the bubble interface as compared to that in clean CMC solution.However,for 10<Re<40,a transition of drag curve from 24/Re to 16/Re in contaminated CMC solution is observed,which is easy at low SDS concentrations and high CMC concentrations.
文摘A novel surface active monomer （surfmer） containing poly（ethylene glycol） chain and terminated phosphate group was synthesized. The copolymerization of synthesized surfmer with NVP （N-vinylpyrrolidone） and with NVP and VEP （5-tert-butylperoxy-5-methyl-2-hexene-3-yne monomer） led to formation of corresponding surface-active copolymers. The capability of application of resulted copolymers as surface active macroinitiators of emulsion polymerization of styrene and as components of polymeric scaffolds was investigated.
