College of Materials Science & Engineering, Zhejiang University of Technology, Hangzhou 310014, PR China.
Department of Chemical, Biomolecular and Corrosion Engineering. The University of Akron, Ohio 44325, United States.
ACS Appl Mater Interfaces. 2020 Sep 16;12(37):42169-42178. doi: 10.1021/acsami.0c12399. Epub 2020 Sep 4.
Continuously growing interest in the controlled and tunable transport or separation of target molecules has attracted more attention recently. However, traditional "on-off" stimuli-responsive membranes are limited to nongradient feedback, which manifests as filtration efficiency that cannot be increased or decreased gradually along with the different stimuli conditions; indeed, only the transformation of on/off state is visible. Herein, we design and fabricate a series of robust salt-responsive SiO@cellulose membranes (SRMs) by simply combining salt-responsive poly[3-(dimethyl(4-vinylbenzyl)ammonium)propyl sulfonate] (polyDVBAPS)-modified SiO nanoparticles and cellulose membranes under negative-pressure filtering. The antipolyelectrolyte effect induces stretch/shrinkage of polyDVBAPS chains inside the channels and facilities the directional aperture size and surface wettability variation, greatly enhancing the variability of interfacial transport and separation efficiency. Due to the linear salt-responsive feedback mechanism, the optimal SRMs achieve highly efficient target macromolecule separation (>75%) and rapid oil/saline separation (>97%) with a continuous gradient and adjustable permeability, instead of simply an "on-off" switch. The salt-responsive factors (SiO-polyDVBAPS) could be reversibly separated or self-assembled to membrane substrates; thus, SRMs achieved unprecedented repeatability and reusability even after long-term cyclic testing, which exceeds those of currently reported membranes. Such SRMs possess simultaneously a superfast responsive time, a controllable gradient permeability, a high gating ratio, and an excellent reusability, making our strategy a potentially exciting approach for efficient osmotic transportation and target molecule separation in a more controllable manner.
最近，人们对目标分子的可控和可调传输或分离越来越感兴趣。然而，传统的“开/关”刺激响应膜仅限于非渐变反馈，表现为过滤效率不能随着不同的刺激条件逐渐增加或减少；实际上，只能看到开/关状态的转换。在此，我们通过简单地将盐响应性聚[3-（二甲基（4-乙烯基苄基）铵）丙基磺酸盐]（polyDVBAPS）改性的 SiO2 纳米粒子和纤维素膜在负压过滤下组合，设计并制备了一系列坚固的盐响应 SiO@纤维素膜（SRM）。反聚电解质效应诱导了 polyDVBAPS 链在通道内的伸缩，促进了定向孔径大小和表面润湿性的变化，极大地增强了界面传输和分离效率的可变性。由于线性盐响应反馈机制，最佳的 SRM 实现了高效的目标大分子分离（>75%）和快速的油/盐水分离（>97%），具有连续的梯度和可调的渗透性，而不是简单的“开/关”开关。盐响应因子（SiO2-polyDVBAPS）可以可逆地分离或自组装到膜基底上；因此，SRM 即使在长期循环测试后也实现了前所未有的重复性和可重复性，超过了目前报道的膜。这种 SRM 具有超快的响应时间、可控制的梯度渗透性、高门控比和优异的可重复性，使我们的策略成为以更可控的方式实现高效渗透传输和目标分子分离的一种很有前途的方法。
