Wallenberg Wood Science Center, School of Chemical Science and Engineering, KTH Royal Institute of Technology , SE-100 44 Stockholm, Sweden.
Department of Fibre and Polymer Technology, School of Chemical Science and Engineering, KTH Royal Institute of Technology , SE-100 44 Stockholm, Sweden.
ACS Appl Mater Interfaces. 2016 Sep 14;8(36):24161-7. doi: 10.1021/acsami.6b05673. Epub 2016 Aug 31.
The surface of regenerated cellulose membranes was modified by irreversible adsorption of carboxymethylcellulose (CMC). Pairs of wet CMC-modified membranes were laminated with polyvinylamine (PVAm) at room temperature, and the delamination force for wet membranes was measured for both dried and never-dried laminates. The wet adhesion was studied as a function of PVAm molecular weight, amine content, and deposition pH of the polyelectrolyte. Surprisingly the PVAm-CMC system gave substantial wet adhesion that exceeded that of TEMPO-oxidized membranes with PVAm for both dried and never-dried laminates. The greatest wet adhesion was achieved for fully hydrolyzed high molecular weight PVAm. Bulk carboxymethylation of cellulose membranes gave inferior wet adhesion combined with PVAm as compared to CMC adsorption which indicates that a CMC layer of the order of 10 nm was necessary. There are no obvious covalent cross-linking reactions between CMC and PVAm at room temperature, and on the basis of our results, we are instead attributing the wet adhesion to complex formation between the PVAm and the irreversibly adsorbed CMC at the cellulose surface. We propose that interdigitation of PVAm chains into the CMC layer is responsible for the high wet adhesion values.
再生纤维素膜的表面通过不可逆吸附羧甲基纤维素（CMC）进行修饰。将湿的 CMC 修饰膜对与聚乙烯亚胺（PVAm）在室温下进行层压，测量湿膜的分层力，包括干燥和从未干燥的层压板。研究了湿粘附作为 PVAm 分子量、胺含量和聚电解质沉积 pH 的函数。令人惊讶的是，对于干燥和从未干燥的层压板，PVAm-CMC 系统的湿粘附显著超过了 TEMPO 氧化膜与 PVAm 的湿粘附。对于完全水解的高分子量 PVAm，实现了最大的湿粘附。与 CMC 吸附相比，纤维素膜的羧甲基化会导致较差的湿粘附，这表明需要大约 10nm 的 CMC 层。在室温下，CMC 和 PVAm 之间没有明显的共价交联反应，根据我们的结果，我们将湿粘附归因于在纤维素表面不可逆吸附的 CMC 与 PVAm 之间的复杂形成。我们提出，PVAm 链插入 CMC 层的互穿插是高湿粘附值的原因。
