Rath Gabriela, Mazzali Davide, Zarbakhsh Ali, Resmini Marina
School of Physical & Chemical Sciences, Queen Mary University of London, Joseph Priestley Building, Mile End Road, London E1 4NS, UK.
Polymers (Basel). 2024 Dec 18;16(24):3532. doi: 10.3390/polym16243532.
Microgels, combining the properties of hydrogels and microparticles, are emerging as versatile materials for varied applications such as drug delivery and sensing, although the precise control of particle size remains a challenge. Advances in synthetic methodologies have provided new tools for tailoring of properties, however costs and scalability of the processes remains a limitation. We report here the water-based synthesis of a library of -isopropylacrylamide-based microgels covalently crosslinked with varying contents of ,-methylenebisacrylamide. The results highlight the versatility of water as a synthetic medium, which yields large and monodisperse microgels, with excellent control over size. Dynamic light scattering data demonstrate that by increasing the total monomer concentration from 1 to 3 wt%, the particle size is increased by up to 4.9-fold. Crosslinker content allows fine-tuning of microgel size, with greater relevance for functionalised microgels. Functional co-monomers such as -(3-aminopropyl)methacrylamide hydrochloride and -(hydroxymethyl)acrylamide are shown to influence size and thermoresponsive behaviour, with hydrogen-bonding monomers reducing particle size and increasing the volume phase transition temperature by 2 °C. Positively charged monomers show a size reduction upon heating but provide colloidal stability at temperatures up to 60 °C. These findings emphasize the importance of tailoring synthetic conditions and formulations to optimize microgel properties for specific applications.
微凝胶结合了水凝胶和微粒的特性，正成为用于药物递送和传感等各种应用的多功能材料，尽管精确控制粒径仍然是一个挑战。合成方法的进展为定制性能提供了新工具，然而这些过程的成本和可扩展性仍然是一个限制因素。我们在此报告基于水的合成方法，制备了一系列以N-异丙基丙烯酰胺为基础、与不同含量的N,N'-亚甲基双丙烯酰胺共价交联的微凝胶。结果突出了水作为合成介质的多功能性，它能产生大尺寸且单分散的微凝胶，并能对尺寸进行出色的控制。动态光散射数据表明，通过将总单体浓度从1 wt%提高到3 wt%，粒径增大了4.9倍。交联剂含量可对微凝胶尺寸进行微调，这对功能化微凝胶更为重要。诸如3-氨丙基甲基丙烯酰胺盐酸盐和羟甲基丙烯酰胺等功能性共聚单体被证明会影响尺寸和热响应行为，氢键单体可减小粒径并使体积相变温度提高2℃。带正电荷的单体在加热时尺寸减小，但在高达60℃的温度下能提供胶体稳定性。这些发现强调了定制合成条件和配方以优化微凝胶性能用于特定应用的重要性。
