Studies of intra- and intermolecular interactions in pH-responsive polyampholyte solutions are essential for understanding protein molecule solution behavior and cell organelle organization. Understanding and controlling the formation of intra/intermolecular complexes of synthetic polyampholytes can broaden their applications in industry and the biomedical field. Studies of poly(cation-co-anion) statistical copolymer solutions with a predominant content of the same-charge groups in the polymer chain are present in the theory when the factual experimental data are underrepresented. Herein, we explored the controlled synthesis of poly(methacrylic acid) copolymers containing primary amine groups and studied the copolymer solution aggregation under various pH and salt conditions. Well-defined poly(methacrylic acid-co-3-(aminopropyl)-methacryl amide) copolymers (M_w of 45 kDa and 80 kDa, Đ < 1.36) with a varied content of the amine group (PMAA–NH₂ from 2 to 6 mol%) were synthesized via reversible addition–fragmentation chain transfer (RAFT) copolymerization. Both computational and experimental studies proved the copolymerization of tert-butyl methacrylate with N-(tert-butoxycarbonyl-aminopropyl)methacrylamide where the second monomer is less active in copolymerization due to strong interaction with a chain-transfer agent (CTA). We found that the resulting PMAA–NH₂ copolymers with more than 4 mol% of amine groups form polyampholyte complexes (PACs) in solution in the pH range from 3.1 to 4.8 due to charge compensation. Given the ability of this PMAA–NH₂ to undergo multilayer assembly at surfaces and controlled crosslinking, our findings can be further expanded to develop advanced and tunable PMAA thin multilayer hydrogels. The synthesis of PMAA–NH₂ copolymers via controlled copolymerization can also lead to facile alternatives for PAC synthesis without using cell-toxic cationic polyelectrolytes such as polyvinylpyridines or polyamines. The copolymers can help develop synthetic routes to novel copolymers and new hydrogel materials with controlled nanostructured architectures, environmentally adaptable microcontinents, PAC-based saloplastics, absorbents, anisotropically structured nanocoatings, and biomedical coatings.

中文翻译：

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聚（甲基丙烯酸）聚两性电解质的受控合成和 pH 敏感络合


研究 pH 响应型聚两性电解质溶液中的分子内和分子间相互作用对于了解蛋白质分子溶液行为和细胞器组织至关重要。了解和控制合成聚两性电解质分子内/分子间复合物的形成可以扩大其在工业和生物医学领域的应用。当实际实验数据代表性不足时，对聚合物链中具有主要含量的相同电荷基团的聚（阳离子-共-阴离子）统计共聚物溶液的研究存在于理论中。在此，我们探索了含有伯胺基团的聚（甲基丙烯酸）共聚物的受控合成，并研究了在不同pH和盐条件下共聚物溶液的聚集。具有不同胺基含量（ PMAA– NH ₂从₂ 6 mol%）是通过可逆加成-断裂链转移（RAFT）共聚合成的。计算和实验研究都证明了甲基丙烯酸叔丁酯与N- (叔丁氧基羰基氨基丙基)甲基丙烯酰胺的共聚，其中第二单体由于与链转移剂(CTA)的强相互作用而在共聚中活性较低。我们发现，由于电荷补偿，所得的具有超过4 mol%胺基的PMAA-NH ₂共聚物在pH范围为3.1至4.8的溶液中形成聚两性电解质复合物（PAC）。 鉴于这种 PMAA-NH ₂能够在表面进行多层组装和受控交联，我们的研究结果可以进一步扩展，以开发先进且可调节的 PMAA 薄多层水凝胶。通过受控共聚合成 PMAA-NH ₂共聚物也可以成为 PAC 合成的简便替代品，而无需使用细胞毒性的阳离子聚电解质，例如聚乙烯吡啶或多胺。这些共聚物可以帮助开发新型共聚物和新型水凝胶材料的合成路线，这些材料具有受控的纳米结构结构、环境适应性微大陆、PAC基液体塑料、吸收剂、各向异性结构的纳米涂层和生物医学涂层。