Cleaning by Surfactant Gradients: Particulate Removal from Porous Materials and the Significance of Rinsing in Laundry Detergency
Cleaning by Surfactant Gradients: Particulate Removal from Porous Materials and the Significance of Rinsing in Laundry Detergency
复制标题
表面活性剂梯度清洁：多孔材料中的颗粒去除以及漂洗在洗衣洗涤中的意义
DOI：
10.1103/physrevapplied.9.034012
复制
发表时间：
2018-03-16
影响因子：
4.6
通讯作者：
Stone, Howard A.
中科院分区：
文献类型：
--
作者：
Shin, Sangwoo;Warren, Patrick B.;Stone, Howard A.
Removing particles from fibrous materials involves loosening via surfactants followed by particle transfer in a flow. While flow advection is commonly believed to be the major driver for pore-scale transport, small pores within the fabric do not allow any significant fluid flow inside them, thus significantly reducing the role of advection. However, rinsing the fabric with fresh water naturally establishes a surfactant gradient within the pore space, providing a suitable environment for particles to undergo diffusiophoresis. We demonstrate that this mechanism can remove particles from deep within fabric pores at an accelerated rate. The nonlinear aspect of diffusiophoresis significantly prolongs the lifetime of the phoretic motion beyond the naive solute diffusion time scale during rinsing, allowing long-lasting, continuous removal of particles. Moreover, owing to the fine balance between chemiphoresis and electrophoresis for particles in anionic surfactant concentration gradients, we show that the particle removal is sensitive to the counterion mobility, suggesting a simple route to control the effect. We thus claim to have resolved the "stagnant core problem"-a long-standing mystery in laundry detergency-and have identified a physicochemical approach to particle transport in fibrous media with broad applicability.
