Probing intermolecular and surface interactions of smart polymers

聚合物在许多工程和生物医学应用中发挥着重要作用。许多涉及聚合物的工业过程和生物医学应用依赖于它们基本的分子间和界面相互作用。在过去的三十年里，人们在理解聚合物的粘附、摩擦和润滑以及开发功能聚合物方面做了大量的努力并取得了重大进展。然而，对刺激响应或所谓的“智能”聚合物的分子间力和表面力的定量理解，特别是在可变形表面上，在复杂流体中的气泡（例如，液滴），是相当有限的，这与加拿大自然资源工业中的许多化学过程和操作高度相关。（例如矿物浮选、沥青提取、油砂生产中的水力运输、尾矿水处理）。* 在这个拟议的计划中，将使用系统的方法来利用复杂环境条件下刺激响应聚合物的物理化学性质和基本分子相互作用机制，以阐明它们在分子，纳米和微米尺度上的结构-性质相关性。我们将使用几种最先进的和互补的纳米机械技术，包括表面力装置（SFA），原子力显微镜（AFM）与特殊的气泡/液滴探针技术和反射干涉法相结合，以及自制的四辊磨流体装置，作为主要的研究工具：（1）量化分子间力和表面力智能聚合物在可变形界面处的相互作用（例如疏水相互作用）（例如气泡、液滴），（2）采用生物激发的湿粘附策略，例如DOPA（3，4-二羟基苯基-L-丙氨酸）化学，阳离子-pi相互作用，和刺激敏感的官能团，开发具有可控本体和表面特性的新型粘合剂聚合物和智能自修复聚合物（例如粘附性、弹性和疏水性），并阐明它们的分子相互作用机制和性质-结构关系。对这些智能聚合物的性质和分子相互作用机制的基本和定量理解将为更先进的功能材料的设计原理和开发以及尖端技术提供重要见解，以更好地控制和有效调节许多工业操作（例如聚合物反应工程，矿石浮选）。

Polymers play important roles in numerous engineering and biomedical applications. Many industrial processes and biomedical applications where polymers are involved rely on their fundamental intermolecular and interfacial interactions. Over the past three decades, much effort and significant progress has been made in understanding the adhesion, friction and lubrication of polymers and development of functional polymers. Yet, the quantitative understanding of the intermolecular and surface forces of stimuli-responsive or so-called "smart" polymers, particularly at deformable surfaces (e.g. bubbles, liquid droplets) in complex fluids, is rather limited, which is highly related to many chemical processes and operations in the natural resources industries of Canada (e.g. mineral flotation, bitumen extraction, hydrotransport in oil sands production, tailings water treatment). ***In this proposed program, a systematic approach will be used to exploit the physicochemical properties and fundamental molecular interaction mechanisms of stimuli-responsive polymers in complex environmental conditions, to elucidate their structure-property correlations at the molecular, nano- and micro-scale. We will use several state-of-the-art and complementary nanomechanical techniques, including surface forces apparatus (SFA), atomic force microscope (AFM) coupled with a special bubble/drop probe technique and reflection interferometry, and a home-built 4-roll mill fluidic device, as the main research tools to: (1) quantify the intermolecular and surface forces (e.g. hydrophobic interactions) of smart polymers at deformable interfaces (e.g. bubbles, liquid droplets), (2) adopt bio-inspired wet adhesion strategies such as DOPA (3, 4-dihydroxyphenyl-L-alanine) chemistry, cation-pi interaction, and stimuli-sensitive function groups to develop novel adhesive polymers and smart self-healing polymers with controllable bulk and surface properties (e.g. adhesion, elasticity, and hydrophobicity), and elucidate their molecular interaction mechanisms and property-structure relationships. The fundamental and quantitative understanding of the properties and molecular interaction mechanisms of these smart polymers will provide significant insights into the design principles and development of more advanced functional materials as well as cutting-edge technologies for better control and effective modulation of many industrial operations (e.g. polymer reaction engineering, ore flotation).