Altering Physical Properties of Particles with Surface Roughness - Anomalous Properties of 'Hedgehog' Particles.

hedgehog particles;rough particles;anomalous dispersion;light scattering;EDLVO;Biomedical Engineering;Engineering;Biomedical Engineering

Bahng, Joong HwanVanEpps, J Scott ;

University of Michigan

关键词: hedgehog particles;    rough particles;    anomalous dispersion;    light scattering;    EDLVO;    Biomedical Engineering;    Engineering;    Biomedical Engineering;   

Others  :  https://deepblue.lib.umich.edu/bitstream/handle/2027.42/135736/joonghb_1.pdf?sequence=1&isAllowed=y

瑞士|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

Particles are ubiquitous and are integral components of modern technology. Sensitive to any alterations or even a small perturbation in its constitutive properties, sizes and shapes, particles have been utilized as a versatile means in a compact platform with which to manipulate, enhance or transform any physico-chemical properties in its environment. Amongst the variety, procedural and synthetic diversities and accompanying investigation of the physical and chemical properties of micron-scale particles having highly rough surfaces is barren in previous studies.Yet, most of the particles found in nature are ;;rough” particles. Therefore, a thorough surveythat maps the deviation in properties from what is expected of standard predictions from analytically ;;smooth” particles, accompanied by systematic analysis protocols, is expected bring a broad impact to multiple scientific and practical disciplines.In the early phase of the research as a precursor to the construction of ;;rough” particles, the focus was on the synthesis of smooth polymeric microspheres. As microspheres had been extensively characterized, the focus was on the development and streamlining of large-scale fabrication process based on microfluidics setup. The second phase of the research involved the synthesis and characterization of ;;rough” particles having orthogonal orientation of high aspect ratio ZnO nanospikes on polymeric microspheres, which we called the ;;hedgehog’ particles to reflect its morphology. In this phase, we studied the ;;hedgehog’ particles in a colloidal system and report an anomalous colloidal dispersion behavior Lastly, owing to unique geometrical and material configurations, the ;;hedgehog’ particles enabled us to study electromagnetic response of ;;rough” particles, where all of its photonic compartments are dielectric and lie within the Mie scattering regime. Here, we showed that the presence of surface roughness alters the electromagnetic responses from what would have been expected of typical micron-scale dielectric particles. These studies are only a small subset of synthetic and property diversities possible with ;;rough” particle configurations. We believe that continued investigation and further expansion in the knowledge of ;;rough”, as well as particles of other configurations, may enable us a spectrum of design possibilities for realizing high performance substrates and devices.