Silica ‘spiky screws’ could enhance industrial coatings additive manufacturing

The screw-like spikes grown from a spherical silica particle depicted above may alter the internal strength of materials used in industrial coatings, 3D printing and other additively manufactured objects.

Researchers at the Department of Energy’s Oak Ridge National Laboratory developed a molecular process to improve silica structure’s design by introducing microscopic, segmented screw-like spikes that can more effectively bond materials.

The study, conducted by Jaswinder Sharma and his colleagues Panos Datskos and David Cullen, has been published in the international edition of ‘Angewandte Chemie’ (applied chemistry). The authors state that other applications of the screw-like spikes could include coatings for eyeglasses, television screens, commercial transportation and even self-cleaning windows and roofs in rural as well as urban environments.

The new, segmented spikes, created by emulsion droplets applied to a silica particle’s surface, offer an alternative tool for material scientists and engineers that can better maintain and fuse bonds within a variety of microstructures. Combined with tetraethyl orthosilicate, an additive molecule, the emulsion droplets begin to produce rod-like spikes whose growth can be controlled for silica structures and configured into new materials.

The segmented spike’s development is an enhanced version of previous research conducted by the team. Sharma explained that the screw-like shape of these spikes was achieved when temperature control was incorporated with the spike growth on preformed particles. In previous experiments, the spikes appeared in a rod-like, linear shape, preventing the silica from bending into the diverse shapes Sharma’s team wanted to create from the particle seeds.

“If you try to use these linear ones, they will lie down like a pen does,” Sharma explains. “They won’t stand, but if you have the segmented, spiky screws or smooth spiky screws, they will stand. They are the better shape.”

According to the authors, the spike’s most direct application rests on interface engineering and the ongoing advancements in additive manufacturing, ORNL’s another significant research area.

Authors also experimented with a hybrid structure made from silica and titania, confirming that the silica-based spike growth can work for other oxide materials as well.