Silica ‘spiky screws’ could enhance industrial coatings
25 June 2015
Research mimicking the spike-like structure of marine sponges might soon influence how industrial coatings and additively manufactured objects are produced.
A molecular process developed by researchers at Oak Ridge National Laboratory in the US, is paving the way for improved silica structure design by introducing microscopic, segmented screw-like spikes that can more effectively bond materials for commercial use.
The study, conducted by Jaswinder Sharma and his colleagues Panos Datskos and David Cullen, is published in the journal, Angewandte Chemie. The authors believe 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 and urban environments.
Created by emulsion droplets applied to a silica particle’s surface, the new, segmented spikes 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 development of a segmented spike comes as an enhanced version of previous research conducted by the team. Sharma says 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 sought to create from the particle seeds.
“If you try to use these linear ones, they will lie down like a pen does,” says Sharma. “They won’t stand. But if you have the segmented, spiky screws or smooth spiky screws, they will stand. They are the better shape.” The segmented spike’s most direct application rests on interface engineering and the ongoing advancements in additive manufacturing.
With the spikes’ new shape, materials for bonding layers can maintain a stronger internal structure, lasting longer than previously used approaches.
The researchers also experimented with a hybrid structure made from silica and oxide of titanium, confirming that the silica-based spike growth can work for other oxide materials as well.