John A. Paulson School of Engineering and Applied Sciences, Kavli Institute for Bionano Science and Technology, Harvard University, Cambridge, MA, 02138, USA.
Adv Healthc Mater. 2019 Oct;8(19):e1900810. doi: 10.1002/adhm.201900810. Epub 2019 Jul 31.
The integration of soft materials-biological tissues, gels, and elastomers-is a rapidly developing technology of this time. Whereas hard materials are adhered using adhesives of hard polymers since antiquity, these hard polymers are generally unsuited to adhere soft materials, because hard polymers constrain the deformation of soft materials. This paper describes a design principle to use hard polymers to adhere soft materials, such that adhesion remains tough after the adhered soft materials are subject to many cycles of large stretches in the plane of their interface. The two soft materials have stretchable polymer networks, but need not have functional groups for adhesion. The two soft materials are adhered by forming, in situ at their interface, islands of a hard polymer. The adhesion is tough if the islands themselves are strong, and the polymers of the islands are in topological entanglement with the polymer networks of the soft materials. The adhesion is stretchable if the islands are smaller than the flaw sensitivity length. Several methods of forming the hard polymer islands are demonstrated, and the mechanics and chemistry of adhesion are studied. The design principle will enable many hard polymers to form tough and stretchable adhesion between soft materials.
软物质-生物组织、凝胶和弹性体的整合是当前快速发展的技术。自古以来，硬材料都是通过硬聚合物的粘合剂来粘结的，而这些硬聚合物通常不适合粘结软物质，因为硬聚合物限制了软物质的变形。本文描述了一种使用硬聚合物粘结软物质的设计原理，使得在粘结的软物质在其界面的平面上经历多次大拉伸循环后，粘结仍然具有韧性。这两种软物质都具有可拉伸的聚合物网络，但不需要具有用于粘结的官能团。通过在它们的界面处原位形成硬聚合物的岛来实现粘结。如果岛本身很强，并且岛中的聚合物与软物质的聚合物网络具有拓扑缠结，则粘结具有韧性。如果岛小于缺陷敏感长度，则粘结具有可拉伸性。展示了几种形成硬聚合物岛的方法，并研究了粘结的力学和化学性质。该设计原理将使许多硬聚合物能够在软物质之间形成坚韧且具有拉伸性的粘结。
