Particle-surface adhesive forces and their role in resuspension phenomena

受益于巴斯大学和布里斯托尔大学在胶体科学和气溶胶方面的互补专业知识，学生将应用各种技术来探索控制初级粒子从表面重新悬浮的物理化学因素。该项目将通过逐步增加实验的复杂性以及机械模型的开发和验证，探索不同类型和形态的表面，包括基质和颗粒。具体目标将包括：1.使用3D打印和薄膜涂层等技术组合，开发一系列具有可控形态、疏水性和表面能量的模型表面。使用胶体探针原子力显微镜(AFM)测量这些表面与控制形态的盐和糖颗粒之间的粘附力分布。研究环境湿度对粘附力分布的影响。将测得的粘附力分布应用到机械自适应Biasi摇滚乐模型中。评估再悬浮风洞中已识别的表面和粒子的子集。这将验证方法，并将AFM研究的单粒子相互作用与风洞再悬浮的复杂性联系起来。如果模型表面和粒子的初始工作成功，该方法将扩展到包括一系列感兴趣的真实表面和粒子(例如混凝土、细菌介质)。

Benefitting from complementary expertise in colloid science and aerosols at the universities of Bath and Bristol, the student will apply a variety of techniques to explore the physicochemical factors controlling resuspension of primary particles from surfaces. The project will progress through stepwise increases in experimental complexity coupled with mechanistic model development and validation, exploring different types and morphology of surface, both substrate and particle.Specific objectives will include:1. Develop a range of model surfaces with controlled morphology, hydrophobicity and surface energy, using a combination of techniques such as 3D printing and thin film coating.2. Measure adhesive force distributions between these surfaces and salt and sugar particles of controlled morphology using colloidal probe atomic force microscopy (AFM).3. Investigate the effect of environmental humidity on these adhesive force distributions.4. Implement the measured adhesive force distributions into the mechanistic Adaptive Biasi Rock-and-Roll Model.5. Assess a subset of identified surfaces and particles in the resuspension wind tunnel. This will validate approaches and relate the single particle interactions investigated by AFM to the complexities of wind tunnel resuspension.If initial work with model surfaces and particles is successful, the approach will be extended to include a range of realistic surfaces and particles of interest (e.g. concrete, bacteriological media).