CROSS-COPOLYMER NETWORKS: TOWARDS TUNABLE, MULTIRESPONSIVE HYDROGELS

聚合物网络构成了许多最重要的工业材料，如热固性材料、弹性体和凝胶，全球年产量估计为6500万吨。水凝胶是交联的亲水性聚合物的水溶胀网络，其用于日常个人护理产品，如超吸收剂、隐形眼镜或伤口敷料，以及新兴的高级应用，例如，与其他聚合物网络类似，绝大多数水凝胶是单组分的，即由一种类型的聚合物组成。这是由于交联过程的性质，其产生随机交联的不溶性凝胶，难以进一步改性。因此，在常规网络/水凝胶中可获得的性质范围受到聚合物的选择的限制。因此，为了合成具有可调性质以及独立响应多种刺激（如温度或pH）的能力的功能性水凝胶，需要开发新颖的非常规网络结构。该项目将寻求引入一种新型的水凝胶，更一般地说，聚合物网络，由两种不同的聚合物组合在一个单一的网络中，称为交叉共聚物网络（CCN）。在CCN中，两种聚合物以顺序方式合成和交联，允许独立控制网络的每个“半”的参数。CCN水凝胶的合成将进行概念验证研究，以研究其内部结构和物理性质。将合成具有CCN结构的模型刺激响应性水凝胶，以评估内部结构对热和/或pH诱导的相变的影响。精确调节CCN水凝胶相变的能力将允许更好地控制其网孔尺寸和传输特性，从而产生用于受控药物递送、“智能”伤口敷料和其他生物医学应用的新的生物相容性材料。

Polymer networks constitute many of the most important industrial materials such as thermosets, elastomers and gels, with annual global production estimated at 65 million tons. Hydrogels are water-swollen networks of crosslinked hydrophilic polymers which are used in everyday personal care products such as superabsorbents, contact lenses or wound dressings, as well as in emerging advanced applications, e.g., controlled drug delivery systems, tissue engineering and 'smart' stimuli-responsive (bio)materials.Similar to other polymer networks, the vast majority of hydrogels are one-component, i.e. consist of one type of polymer. This is due to the nature of the crosslinking process, which produces randomly crosslinked insoluble gels, difficult for further modification. Consequently, the range of properties accessible in conventional networks/hydrogels is limited by the choice of the polymer. Thus, in order to synthesise functional hydrogels with tuneable properties as well as the ability to independently respond to multiple stimuli such as temperature or pH, novel, unconventional network architectures need to be developed. This project will seek to introduce a new type of hydrogels, and, more generally, polymer networks, composed of two different polymers combined within a single network, referred to as cross-copolymer networks (CCN). In CCNs, two polymers are synthesized and crosslinked in a sequential manner, allowing to independently control the parameters of each 'half' of the network. Proof-of-concept studies on the synthesis of CCN hydrogels will be undertaken to investigate their internal structure and physical properties. Model stimuli-responsive hydrogels with a CCN architecture will be synthesized to evaluate the impact of the internal structure on thermal and/or pH-induced phase transitions. The ability to precisely tune the CCN hydrogel's phase transitions will allow better control over their mesh size and transport properties resulting in new biocompatible materials for controlled drug delivery, 'smart' wound dressings, and other biomedical applications.