微粒已应用于许多领域,从药物输送,诊断,化妆品,个人护理,和食品工业的化学和催化反应,传感,和环境修复。涂层进一步为微粒提供额外的功能,如控释,表面改性,抗生物污垢,稳定性,保护,等。在这项研究中,带有带正电荷的聚电解质(聚烯丙胺盐酸盐,提出并演示了利用声流控微芯片的PAH)。多个层流,包括PAH解决方案,在微通道内形成,and,在行进的表面声波下,微粒穿过溪流,在那里他们被PAH涂层。结果表明,与通过分批方法获得的方法相比,通过微流体方法可以快速实现微粒的涂覆。此外,通过微流体方法涂覆的微粒的ζ电位更均匀。对于未功能化的微粒,电荷反转发生在涂覆后,并且zeta电位随着微通道的宽度或PAH溶液浓度的增加而增加。至于羧酸盐结合的微粒,涂覆后再次出现电荷反转;然而,当使用具有不同宽度或不同浓度的PAH溶液的微通道时,ζ电位的大小相似。
Microparticles have been applied in many areas, ranging from drug delivery, diagnostics, cosmetics, personal care, and the food industry to chemical and catalytic reactions, sensing, and environmental remediation. Coating further provides additional functionality to the microparticles, such as controlled release, surface modification, bio-fouling resistance, stability, protection, etc. In this study, the conformal coating of microparticles with a positively charged polyelectrolyte (polyallylamine hydrochloride, PAH) by utilizing an acoustofluidic microchip was proposed and demonstrated. The multiple laminar streams, including the PAH solution, were formed inside the microchannel, and, under the traveling surface acoustic wave, the microparticles traversed through the streams, where they were coated with PAH. The results showed that the coating of microparticles can be achieved in a rapid fashion via a microfluidic approach compared to that obtained by the batch method. Moreover, the zeta potentials of the microparticles coated via the microfluidic approach were more uniform. For the unfunctionalized microparticles, the charge reversal occurred after coating, and the zeta potential increased as the width of the microchannel or the concentration of the PAH solution increased. As for the carboxylate-conjugated microparticles, the charge reversal again occurred after coating; however, the magnitudes of the zeta potentials were similar when using the microchannels with different widths or different concentrations of PAH solution.