Coating porous membranes with a photocatalyst: Comparison of LbL self-assembly and plasma-enhanced CVD techniques
Coating porous membranes with a photocatalyst: Comparison of LbL self-assembly and plasma-enhanced CVD techniques
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DOI：
10.1016/j.memsci.2016.04.050
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发表时间：
2016-09-15
影响因子：
9.5
通讯作者：
Ayral, Andre
中科院分区：
文献类型：
--
作者：
Starr, Brian J.;Tarabara, Volodymyr V.;Ayral, Andre
比较评价了用光催化剂在膜支撑层的大孔表面涂覆的两种方法。纳米二氧化钛以多层聚(二烯丙基二甲基氯化铵)和聚丙烯酸为粘结剂逐层自组装，在膜支撑物的颗粒上形成亚单层的光催化剂纳米颗粒。相比之下，等离子体增强化学气相沉积在薄膜颗粒上提供了致密而均匀的涂层。这两种方法都不会降低膜的通透性。以亚甲基蓝为探针化合物，通过过滤实验评价了涂层膜的光催化活性。为了比较两种涂层的光催化性能，反应通量(ETA)的测量值通过在相同催化剂上进行批量试验测定的反应速率常数(k‘’)来归一化。所提出的建模方法将涂层的反应性(eta和k‘’)与以反应区长度(Rz)和涂层密度(Theta)表示的反应器的几何形状联系起来。这两种涂层技术导致类似的涂层质量，如eTa/k‘’的相似值(或等效地，teta L(Rz)的相似值)所证明。拟议的分析为改进每种涂层技术的可能方法提供了见解。(C)2016爱思唯尔B.V.保留所有权利。
Two methods for coating a macroporous surface of a membrane support layer with a photocatalyst are comparatively evaluated. Layer-by-layer self-assembly of nanoTiO(2) with a multilayer of poly(diallyldimethylammonium chloride) and poly(acrylic acid) as a binder produces a sub-monolayer of photo catalyst nanoparticles on the grains of the membrane support. In contrast, plasma-enhanced chemical vapor deposition gives a dense uniform coating on the membrane grains. Neither method reduces membrane permeability. The photocatalytic activity of the coated membranes was evaluated in filtration tests with methylene blue as a probe compound. To compare photocatalytic performance of the two coatings, measured values of the reactive flux (eta) were normalized by reaction rate constants (k '') determined in batch tests with the same catalyst. The proposed modeling approach relates coating's reactivity (eta and k '') to the reactor's geometry expressed in terms of the length of the reaction zone (l(rz)) and coating density (theta). Both coating techniques result in a similar coating quality as witnessed by similar values of eta/k '' (or, equivalently, similar values of theta l(rz)). The proposed analysis offers insights into possible ways for improving each coating technique. (C) 2016 Elsevier B.V. All rights reserved.