Posted: Jun 24, 2015 |
Silica 'spiky screws' could enhance industrial coatings, additive manufacturing
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(Nanowerk News) It took marine sponges millions of years to perfect their spike-like structures, but research mimicking these formations may soon alter how industrial coatings and 3-D printed to additively manufactured objects are produced.
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A molecular process developed by researchers at the Department of Energy's Oak Ridge National Laboratory, paves the way for improved silica structure design by introducing microscopic, segmented screw-like spikes that can more effectively bond materials for commercial use.
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The study, conducted by Jaswinder Sharma and his colleagues Panos Datskos and David Cullen, has been published in Angewandte Chemie International Edition ("Step-by-Step Growth of Complex Oxide Microstructures"). Authors said 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.
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The screw-like spikes grown from a spherical silica particle depicted above may alter the internal strength of materials used in industrial coatings, 3-D printing and other additively manufactured objects. (Image: ORNL)
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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.
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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.
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The development of a segmented spike comes as 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.
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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.
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"If you try to use these linear ones, they will lie down like a pen does," Sharma said. "They won't stand. But if you have the segmented, spiky screws or smooth spiky screws, they will stand. They are the better shape."
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According to the authors, the segmented spike's most direct application rests on interface engineering and the ongoing advancements in additive manufacturing, another significant ORNL research area.
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With the spikes' new shape, materials for bonding layers can maintain a stronger internal structure, lasting longer than previously used approaches.
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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.
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While they noted the hybrid's use in future processes, the authors said the spectrum of possibilities remains wide open for future researchers to explore.
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"We actually developed a process to create new structures, but we didn't focus on one application when we did that," Sharma said. "We looked at a range of applications where this could fit, and we are now trying to explore all those directions."
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