Novel Thermally Switchable Smart Polymer Films

这笔赠款为一种新型的接枝混合臂三元共聚体系的综合研究提供了资金，该体系显示了它们表面组成的热响应变化。将开发合成路线，以生产具有不同嵌段臂长度的混合臂三元聚合物，并将其嫁接到刚性和柔性底物上。这些接枝共聚物薄膜的热行为将使用先进的实验技术和计算模型进行评估。这些接枝的三元共聚物的行为将首先使用嵌段进行研究，这将导致亲水或疏水表面之间的可逆切换。预计三元共聚物的复杂相行为既受热力学控制，又受动力学控制，因此将研究这些接枝三元共聚体系的相行为，并建立作为相对臂分子量函数的相图。链动力学对平衡和非平衡相行为的影响将被研究，因此对可预测地调节表面能并因此对表面润湿进行评价的能力是关键的。我们将研究温度梯度和局部退火热处理对控制三元共聚物表面侧向润湿行为的影响。该项目的第二阶段将研究三元共聚物相对臂长的不对称对表面曲率和曲率反转的影响。该项目的成功可能会在许多技术应用中产生非常广泛的影响，这些应用中表面行为的控制是重要的，包括表面润湿和粘合以及相反转系统，如乳状液或囊泡。对于不对称三元共聚体系，预计将发生的表面曲率反转将具有明确的随时间变化的动态反转行为，该行为受温度控制。这可能会对智能表面应用产生重要影响，例如药物输送平台，这可能会开辟智能表面行为的新前沿。

This grant provides funding for a comprehensive study of a novel type of grafted miktoarm terpolymer system, which displays thermally responsive changes in their surface composition. Synthetic routes will be developed to produce miktoarm terpolymers with varying block arm lengths grafted onto both rigid and flexible substrates. The thermal behavior of these grafted terpolymer films will be evaluated using advanced experimental techniques and computational modeling. The behavior of these grafted terpolymers will be studied initially using blocks which would lead to reversible switching between hydrophilic or hydrophobic surfaces. The complex phase behaviour of the terpolymer is predicted to be both thermodynamically and kinetically controlled, consequently the phase behavior of these grafted terpolymer systems will be investigated and phase diagrams established as a function of relative arm molecular weights. The influence of chain dynamics on the equilibrium and non-equilibrium phase behavior will be investigated and hence the ability to predictably tune surface energies and therefore surface wetting critically evaluated. The effects of thermal gradients as well as localized annealing to control lateral wetting behavior of the terpolymer surface will be investigated. The effect of asymmetry of the relative arm lengths of the terpolymer on surface curvature and curvature inversion during temperature cycling will be studied in the second phase of the project.Success within the project could have very wide implications in numerous technological applications where control of surface behaviour is important, including surface wetting and adhesion as well as phase inversion systems such as emulsions or vesicles. Surface curvature inversion that is predicted to occur for asymmetric terpolymers systems would have a defined time-dependent dynamic inversion behaviour which is controlled by the temperature. This could have important implications for smart surface applications such as drug delivery platforms, which could open up a new frontier of smart surface behavior.