This research was an attempt to synthesize a series of amphiphilic hydrogels based on different molar ratios of N,N-dimethylacrylamide (DMAM) and acrylic acid (AA) and investigated the influence of pH, time, temperature, and salinity of water on the swelling behavior of the hydrogels. The swelling kinetic parameters and swelling diffusion were also determined. The synthesis of DMAM/AA hydrogel using N,N'-methylenebisacrylamide as a cross-linking agent and AIBN as initiator was confirmed by Fourier transform infrared spectroscopy (FTIR). The swelling results revealed that the hydrogel swelling reduced as a content of AA. Also, it was demonstrated that increasing the pH caused a drastic increment of the equilibrium swelling ratio and the maximum extent (5150%) was reached at pH 14 for sample AHD3 containing 25% AA. The swelling mechanism study showed that for all samples, Fickian diffusion was responsible for water transport as well as the swelling process was considerably influenced by the chemical structure of the monomer repeating units in the synthesized samples. The swelling study of the hydrogel in the aqueous solution of NaCl and Na₂SO₄ showed that increasing the salt concentration caused in limitation of water absorption. Also, the swelling degree in the aqueous solution of Na₂So₄ was slightly higher than NaCl. It was also shown that the increase in temperature of the swelling process led to enhancement of swelling ratio in distilled water.

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中文翻译：

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N,N'-二甲基丙烯酰胺/丙烯酸两亲水凝胶在不同条件下的制备、表征和溶胀研究

本研究尝试基于 N,N-二甲基丙烯酰胺 (DMAM) 和丙烯酸 (AA) 的不同摩尔比合成一系列两亲性水凝胶，并研究了 pH、时间、温度和水的盐度对溶胀的影响。水凝胶的行为。还测定了溶胀动力学参数和溶胀扩散。以 N,N'-亚甲基双丙烯酰胺为交联剂、AIBN 为引发剂合成 DMAM/AA 水凝胶的过程通过傅里叶变换红外光谱 (FTIR) 得到证实。溶胀结果表明，水凝胶溶胀随着 AA 含量的增加而降低。此外，还证明了提高 pH 值会导致平衡溶胀率的急剧增加，并且对于含有 25% AA 的样品 AHD3，在 pH 值为 14 时达到了最大程度（5150%）。溶胀机理研究表明，对于所有样品，Fickian 扩散负责水的传输，并且溶胀过程受到合成样品中单体重复单元化学结构的显着影响。水凝胶在NaCl和Na水溶液中的溶胀研究₂ SO ₄表明增加盐浓度导致吸水受限。此外，Na ₂ So ₄水溶液的溶胀度略高于NaCl。还表明，溶胀过程温度的升高导致蒸馏水中溶胀率的提高。

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