On November 26th 2019, Dr. Hanfeng Liang from King Abdullah University of Science & Technology (KAUST), Dr. Hiroya Nishikawa from RIKEN CEMS, Dr. Aijie Liu from Uppsala University were invited to participate the Soft Matter Sub-forum, and shared the research on their field.

Screw Dislocation-Driven Growth of 1D and 2D Nanomaterials and Their Electrochemical Applications

 Dr. Hanfeng Liang from King Abdullah University of Science & Technology (KAUST)

Dr. Liang shared that o0ne-dimensional (1D) and two-dimensional (2D) nanostructures have exhibited unique fundamental physical properties and demonstrated promising applications in energy storage and conversion. The challenge in growing anisotropic nanostructures is to break the symmetry of crystal growth to promote the formation of highly anisotropic instead of polyhedral crystals. In this talk, Dr. LiangI will discussed a “new” growth mechanism that is fundamentally different from the commonly used metal catalysts-driven growth (such as vapor-liquid-solid, VLS), in which screw dislocations provide the self-perpetuating steps to enable 1D or 2D crystal growth. Dr. Liang I will further discussed the generality and significance of this growth mechanism as well as the electrochemical 

Ferroelectric Fluid showing gigantic polarization properties

Dr. Hiroya Nishikawa from RIKEN CEMS

Dr. Nishikawa shared that a liquid crystal (LC) compound bearing a 1,3-dioxane unit in the mesogenic core (DIO) exhibits an anomalously large dielectric permittivity of ca. 104 in a polar nematic phase (NP) with high fluidity unlike conventional LC. In this temperature range of NP phase, no sharp X-ray diffraction peak is observed at any Bragg angles, similar to that for a nematic phase; however, an inhomogeneous sandy texture is observed through a polarizing optical microscopy, unlike that for a conventional nematic phase. Besides, NP phase exhibits polarization switching with a large polarization value, i.e., P = 4.4 μC cm−2, and a parallelogram-shaped polarization–electric field hysteresis loop, which is also observed in ferroelectrics. The heterogeneously aligned DIO molecules in the ground state shows the tendency of a uniform orientation along the applied electric field, a field-induced polarization switching occurs at the same time. Sufficiently larger second-harmonic generation (SHG) activity is also observed in NP phase. Furthermore, SHG interferometry clearly shows the polarization inversion by reversing the applied electric field in NP phase. These results suggest that a unidirectional, ferroelectric-like parallel polar arrangement of the molecules would be generated along the director in NP phase. For a possible model for large polarization behavior in NP phase, we would like to talk on the day of presentation.

Virus Protein Cages as Building Blocks for Functional Materials

 Dr. Aijie Liu from Uppsala University

Dr. Liu shared that the use of protein architectures for bio-nanotechnology applications is a rapidly emerging field. Protein cages have been widely used as nano-carriers and nano-templates. By mimicking nature, protein cages haves provide a platform to mimic and understand enzymatic activity through integration of reaction reagents in the confinement. However, considering the intrinsic properties of virus protein cages, e.g., dynamic structures, surface charge distributions and limited pores etc., the use of protein cage architectures in functional materials has not fully explored yet. In this work, I will introduce plant virus, Cowpea Chlorotic Mottle Virus (CCMV) as building block to construct multifunctional materials. Where the focus is on gold as a catalyst, to further explore its application as a nanoreactor, but also as the construction material for functional films by either cross-linking the protein cages or using them as a template for silica synthesis.