Adsorption, Aggregation and Structure Formation in Systems of Charged Particles, 2014
From Colloidal to Supracolloidal Assembly
Springer Theses Series

This thesis presents studies on the interaction of soft materials like surfactants and proteins with hard silica nanomaterials. Due to its interdisciplinary nature it combines concepts from the fields of physical chemistry, nanoscience and materials science, yielding to fundamental insights into the structure-directing forces operating at the nano-scale. It is shown that the morphology of surfactant micellar aggregates adsorbed at the surface of nanoparticles and inside tubular nanopores can be tuned on demand by the co-adsorption of a surface modifier. The interaction of globular proteins with silica nanoparticles is dominated by electrostatic interactions and can be controlled by pH and ionic strength, while the bridging of nanoparticles by adsorbed protein molecules leads to large-scale hybrid aggregates of protein with the nanoparticles. Concepts emerging from the role of electrostatic interactions in the hetero-aggregation of nanoparticles with protein molecules are used for the co-assembly of charged microbeads into linear clusters and chains of controllable length.

Introduction.- Methods.- Theory and Modeling.- Surfactant Adsorption and Aggregate Structure at Silica Nanoparticles.- Formation of Cylindrical Micelles in Tubular Nanopores.- Aggregation of Silica Nanoparticles Directed by Adsorption of Lysozyme.- Effect of pH and Salinity on Silica-Lysozyme Hetero-Aggregation.- Protein–Specific Effects of Binding to Silica Nanoparticles.- Permanent Supracolloidal Biparticle Assembly Initiated by An Electric Field.- Summary and Outlook.- Appendix.

My research field is Colloid and Interface science, and more specifically the soft-to-hard matter interactions. I am interested in understanding the interactions of globular proteins, surfactants and lipids (soft matter) with magnetic and nonmagnetic hard nanomaterials. I’ve addressed some fundamental questions about factors governing self-assembly of soft-hard nanocomposite structures. Recently, I’ve extended my research to the field of materials science where I focused on directed self-assembly of isotropic and anisotropic colloidal particles into ordered multi responsive structures using external electric and/or magnetic field. My goal is to continue to work and contribute to the field of colloids and nanoscience.