title: Enhanced nanoflow behaviors of polymer melts using dispersed nanoparticles and ultrasonic vibration.
abstract: In the micro/nano fabrication of polymer nanostructures, a key factor is the favorable nanoflow behavior of polymer melts. Compared with the fluidic hydrodynamics of simple liquids through micro- or macrochannels, the nanoflow behavior of polymer melts, however, is affected much more by nanoscale effects and surface interactions. Therefore, achieving a favorable nanoflow of polymer melts in nanochannels is the key to fabricate high quality polymer nanoproducts. In this paper, the improved nanoflow behaviors of polystyrene melts in ordered porous alumina templates with the addition of nanoparticles and ultrasonic vibration were reported for the first time. Compared with bulk polystyrene (PS), the nanoflow rate of PS melts was enhanced when nanoparticles, such as surface-modified nano-silica (nano-SiO(2)) or β-cyclodextrin (β-CD), were added in a dispersed phase into a polystyrene matrix due to the decrease of the melts' viscosity caused by interactions between nanoparticles and PS segments. The enhancement action of β-CD was observed to be more significant than that of nano-SiO(2) based on the adsorption and the supramolecular self-assembly interactions between PS segments and β-CD. The enhanced nanoflow rate has shown to be more pronounced under ultrasonic vibration than those of the static condition and the low frequency vibration attributed to the synergetic effects of mechanical vibration and ultrasonic oscillation. The nanoflow rate of polymer melts increases with the gradual increase of vibration frequency. The optimal nanoflow behavior can be obtained by simultaneously adding β-CD as dispersed phase into PS matrix and applying ultrasonic vibration in one nanoflow system. These new findings will help the preparation of polymer-based functional nanocomposites, ultrasonic vibration-assisted nanofluidics, and micro/nano injection molding etc.
authors: Department of Industrial and Systems Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, P. R. China. happytw_3000@163.com
authors: Wei
authors: W
authors: Tian
authors: Kai Leung
authors: KL
authors: Yung
authors: Yan
authors: Y
authors: Xu
authors: Longbiao
authors: L
authors: Huang
authors: Jie
authors: J
authors: Kong
authors: Yunchuan
authors: Y
authors: Xie
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D011137:Polystyrenes / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry; D014732:Vibration; D047392:beta-Cyclodextrins / Q000737:chemistry
chemical_list: D011137:Polystyrenes; D047392:beta-Cyclodextrins; D012822:Silicon Dioxide; C031215:betadex; D000537:Aluminum Oxide