基于聚合物笔印刷术的聚合物刷限域生长及多元图案制备研究

Polymer brushes by surface-initiated polymerizations have been employed as a versatile approach for surface modification in areas spanning from tailoring surface and interfacial functionality, environmental engineering and biomedical engineering. Recently, patterned polymer brushes at micro/nano scales have attracted increasing interest, which allows the fundamental studies on the properties of polymer brushes and the applications in fabrication of functional surfaces. However, the growth of polymer brushes under microscale confinement and the preparation of multiplexed patterns remain to be explored. Based on polymer pen lithography (PPL), this work aims to develop new methods to pattern polymer brushes with controlled structures by performing surface-initiated polymerizations within microscale droplet reactors (<pL) generated on a surface. Moreover, we will investigate the surface-initiated polymerization under the three-dimensional spatial confinement within the microreactors. Also, the effect of the catalyst selection and concentration as well as reaction conditions will be examined. Based on the above studies to determine factors to influence the polymerization kinetics and polymer brush morphology, we will explore approaches to tune the grafting density, the height and the feature size of the patterned polymer brushes, which would finally lead to control over the three-dimensional structures. Furthermore, in combination with multiplexed PPL, we will develop techniques to produce patterned arrays of multi-component polymer brushes on the same surface in a parallel manner, realizing high-throughput fabrication of complex patterned surface with tunable structures and compositions. We anticipate this work would pave the way to the construction of multifunctional responsive surface and combinatorial chemical libraries for high-throughput screening.

作为重要的表面修饰手段，表面引发聚合生长聚合物刷在调控表界面功能、传感检测、生物医学、环境治理等领域应用价值广泛。在微纳米尺度构筑图案化聚合物刷，对研究聚合物刷性质与构建功能化表面至关重要，因而日益受到关注。然而微尺度空间限域下的表面引发聚合以及多元复杂聚合物刷图案的研究依然有限。本项目旨在利用聚合物笔印刷术限制聚合物刷在表面微液滴空间内生长，实现聚合物刷纳米结构及多元复杂图案化表面的制备与调控。在细致研究微液滴三维空间限域、催化剂种类浓度、反应体系条件等因素对微尺度聚合反应动力学与聚合物刷形貌影响的基础上，我们拟探索对聚合物刷接枝密度、厚度及图案尺寸进行有效调控的方法，最终确定控制聚合物刷三维形貌的途径。同时，我们将结合多组分聚合物笔印刷技术，开发在同一基底表面平行生长多元聚合物刷图案的方法，实现结构组成可调的复杂图案，以期最终达到多功能响应性表面及组合式高通量筛选平台的目的。

在不同基底表面可控构筑复杂图案化的聚合物微纳结构，构成表界面性质基础研究、化学与生物传感、光电功能器件制备以及高通量筛选与检测等领域的技术基础。本项目立足于表面微纳图案化技术开发，首先以微液滴限域聚合为特色实现了简易高效的厘米级面积聚多巴胺（PDA）精细图案化功能修饰，图案精度可至亚微米级。并且，细致研究了聚合物微图案结构的形貌调控，揭示了液滴组成与尺寸限域在PDA生长中所起的作用。以PDA为图案化模板，本项目研究了对类液体聚合物接枝表面的微图案化功能修饰，如梯度表面构筑，及响应性聚合物接枝，并利用类液体表面的微观无痕抗污特性，实现抗背景非特异性吸附蛋白检测微阵列的制备与光电功能材料的去润湿图案化。此外，项目还研究了微电极在水凝胶表面的印刷制备，并针对凝胶电解质与电极的界面问题，研究了表面微结构化水凝胶、动态自修复凝胶网络与多酚改性凝胶界面在制备高拉伸性（>100%应变）、高力学稳定（数百次应变循环）与长久耐用的凝胶离子微器件方面的应用，包括超级电容器、应变传感器等。所开发表面微纳图案化方法与凝胶改性策略具有批量化与环境友好制备多种功能材料微图案阵列与多功能柔性可穿戴微器件的潜力，可为功能表界面在材料表面改性、生物医学工程、光电微器件、柔性电子与能源材料等领域的应用提供新思路。