基于RAFT/MADIX种子聚合构筑“活性”聚乙烯酯基Janus纳米粒子及其溶液行为研究

Owing to possessing both the size effect of Pickering particle and the amphiphilicity of surfactants, polymeric Janus nanoparticle can be used as a novel and efficient surfactant to apply in perfumed daily chemicals. Although there are several techniques have been developed to produce polymeric Janus nanoparticles at present, such as microfluidics, simultaneous electrohydrodynamic jetting, selective surface modification, controlled phase separation, etc., the development of polymeric Janus nanoparticles are still restricted by drawbacks like big size, uncontrolled morphology and low throughput which causing by the above methods. Hence, here in this project, a method of combination of RAFT/MADIX polymerization, self-assembling of block copolymer and seeded emulsion polymerization, has been used to fabricate “living” polyvinyl esters-based Janus nanoparticles with precise control and high throughput. The solvent behaviors of those polymeric Janus nanoparticles have been studied, and the pH- and temperature-sensitive polymeric Janus nanoparticles have been prepared subsequently. Within the formation of polymeric Janus nanoparticles, the phase separation of monomers with seeds and the aggregation of monomers are the key factors to control the final particle morphologies. With the help of interface free energy minimum principle and cluster migration theory, the parameters such as crosslinking degree and surface wettability of seeds, as well as swelling ability of seeds in monomers, which can alter the interfacial free energy between monomers and seeds, and the migration rate of monomers in seeds, have been investigated. Exploring the formation process of polymeric Janus nanoparticles is helpful to control their morphology and microstructure precisely, and then their properties also can be regulated accordingly. The successful completion of this project can provide a pavement for investigating and developing novel, efficient and high stability polymeric Janus nanoparticles.

乳化剂和Pickering粒子是加香日用品中的重要组分，但二者对于控制乳液的稳定性都具有一定的局限性。兼具乳化剂两亲性和Pickering粒子尺寸效应的Janus聚合物纳米粒子，可作为一种新型、高效的稳定剂应用于加香日用品中。尺寸较大、形貌不可控及批量生产困难等是Janus聚合物纳米粒子发展的瓶颈。本项目拟采用RAFT/MADIX可控聚合，结合嵌段共聚物自组装与种子乳液聚合，可控制备“活性”聚乙烯酯基Janus纳米粒子，并研究其溶液行为。单体与种子聚合物相分离及单体相聚集是影响Janus聚合物纳米粒子形貌的关键因素。本项目将基于界面自由能最低原则和团簇迁移理论，探索导致单体与种子聚合物界面自由能变化及影响单体相在种子聚合物中迁移率的根本原因。对纳米粒子形成机理的研究，有助于对其形貌及性能进行有效调控。本项目的顺利进行将对新型、高效、高稳定性Janus聚合物纳米粒子的研究具有重大意义。

香精香料是食品、日化、医药、印刷等行业的重要原材料。天然香料不仅具有诱人的香味，还具有各种保健养生功能。但是，天然香料直接添加到液态日化用品中时容易受到光、热、辐射等因素的影响，造成其组成成分的挥发与降解。为了更好的发挥天然香料的功效，常将天然香料纳微胶囊化，保护其免受外界环境的干扰。天然香料纳微胶囊应用于纺织品，可使其增加镇定、抑菌、健肤等功能，给我们身心带来更多舒适。目前纺织品加香主要采用喷洒、涂布、浸渍、浸轧等方式将胶囊负载于纺织品上，由于常用的胶囊与纺织品纤维亲和力较弱，容易在水洗过程中从纺织品上脱落。交联剂的添加会增强加香纺织品上胶囊的耐水洗性能，同时也会造成环境污染。本课题拟借助于微乳化技术，结合伪三元相图，系统性研究常用天然高分子壁材理化性质、商用乳化体系性质以及常见天然香料组成成分及含量对天然香料液体纳米胶囊形成能力及性能的影响。其中，重点研究天然香料组成成分及含量对液体纳米胶囊形成能力及其性能的影响，为快速且有针对性的制备天然香料液体纳米胶囊提供科学依据和理论基础。另外，为获得绿色环保及高耐水性性能的加香纺织品，本研究将基于纳米胶囊的尺寸优势，采用真空浸渍的方法，对纺织品进行加香，以获得持久释香及高耐水洗性的加香纺织。