Pyramidal assemblies of colloidal particles by micromolding underneath top-gathering pillar arrays

Effects of particle sizes and dispersion media on micromolding of colloidal silica particles underneath top-gathering pillar patterns

“…In our previous work, from the investigation of the in situ observation of the molding process of the particles dispersed in water, it was inferred that the molding of the particles underneath the top-gathering pillars were caused by the effect of both the convective force and the capillary force among the particles [23]. In this work, it was clarified that the packing density of the assemblies and the number of particles remained on the substrate without being molded depended on the particle size and dispersion media.…”

“…Compared with the drying processes of colloid particles in water [23] and in ethanol as shown in Fig. 5, the molding process, in which the particles moved to from one top-gathering unit to the neighboring unit, were similar, and did not depend on the types of dispersion media.…”

“…Photosensitive organic-inorganic hybrid films were prepared for top-gathering pillar array [22,23]. The material was fabricated from methacryloxypropyl trimethoxysilane (MAPTMS) and methacrylic acid (MA), both of which had photopolymerizable C C double bond groups, and zirconium n-propoxide (Zr(OPr) 4 ) as an inorganic network former by the sol-gel method.…”

“…When patterns of colloidal particles are formed using templates, it is important to control several forces, such as the capillary force between the colloid and template [12,14,15] and the force among the colloidal particles themselves [2,18,19], the convective force [20], and other intermolecular interactions (e.g., van der Waals's force, electrostatic interactions, and hydrogen bonding) [21]. In our recent works, periodic patterns of pyramidal shaped assemblies of monodispersed SiO 2 particles and ZnO powders have been formed successfully by micromolding in top-gathering pillar arrays as a template [22,23].…”

Pyramid-shaped assembly of colloidal particles underneath top-gathering pillars

“…In our recent works, periodic patterns of pyramid-shaped assemblies of monodispersed SiO 2 particles and ZnO powders have been formed successfully by micromolding in top-gathering pillar arrays as a template [20][21][22]. The top-gathering pillar arrays were fabricated by photolithography and by controlling the capillary force during the drying of the development or rinse liquid [23][24][25].…”