science lives shares a report from Science Magazine: The production of glass – one of the oldest materials of mankind – gets a makeover in the 21st century. A new approach to glassmaking treats the material like plastic, allowing scientists to injection mold vaccine vials, meandering channels for lab chemistry, and other complex shapes.
Scientists created a printable powder by mixing silica nanoparticles with a polymer that could be cured with ultraviolet (UV) light. After printing the shapes they wanted, they cured the polymer with UV light to keep its shape. They then fired the mixture in an oven to burn off the polymer and fuse the silica particles into a continuous glass structure. The approach worked, making it possible to create shapes like tiny pretzels and replicas of castle doors. The work has sparked interest from companies wishing to manufacture tiny lenses and other complex transparent optical components for telecommunications equipment. But the process was slow, turning the components one by one, rather than an entirely industrial approach to mass-producing parts, as is the case with plastic.
To speed things up, [the researchers] have now extended their nanocomposite approach to work with injection molding, a process used to mass produce plastic parts like toys and car bumpers by the ton. The researchers started again with tiny particles of silica. The team then mixed the silica with two polymers, polyethylene glycol (PEG) and polyvinylbutyral (PVB). The mixture created a dry powder with the consistency of toothpaste. The team fed the dough into an extruder which pressed it into a preformed mold with shapes such as a disc or a small gear. To harden them, the researchers used water to remove the PEG. They then fired the remaining material in two stages: first at 600 ° C to burn off the PVB, and then at 1300 ° C to fuse the silica particles into the final part. Outside the mold, parts retain their shape as a myriad of weak attractive bonds, called van der Waals interactions, form between neighboring silica particles. But the pieces are still fragile. The report was published in the journal Science.
Molded glass like plastic could usher in a new era of complex glass shapes
Source link Molded glass like plastic could usher in a new era of complex glass shapes