Groundbreaking new reusable adhesive works underwater
by Staff Writers
Chicago IL (SPX) Jan 29, 2019
Illinois researchers have introduced a new cutting-edge reusable adhesive that activates in seconds, works underwater, and is strong enough to deadlift 11 pounds: shape memory polymers (SMPs).
The team - associate professor in mechanical science and engineering Seok Kim, graduate student Jun Kyu Park, and former graduate student Jeffrey D. Eisenhaure (PhD ME '17, now with Northrop Grumman) - has proved that SMPs can retain dry adhesion properties while submerged. Their study, "Reversible underwater dry adhesion of a shape memory polymer," was recently published by the scientific journal Advanced Materials Interfaces(Wiley-VCH).
Classified as a smart material, SMPs have the ability to manually transition between their original state and a deformed state. By manipulating the state of their SMPs, Kim and his team achieved successful adhesion to surfaces submerged in water as well as other liquid media such as oil.
"Dry adhesives, such as those inspired by gecko feet, are believed to be inadequate to achieve high adhesion to a wet or submerged surface," Kim said. "However, this belief has been nullified because of our SMP reversible dry adhesives."
By applying pressure to the submerged SMP in its original rubbery state, liquid can be squeezed out from the contact interface. Under sufficient pressure, the SMP then transitions to a glassy state, essentially creating a hermetic contact condition that maintains highly strong dry adhesion.
However, this state is not permanent; the SMP's shape recovery properties allow for reversal of the adhesion. Furthermore, because the SMP can transition fluently between both states, its adhesion is reusable.
The researchers found that the maximum adhesion strength of the SMP while submerged in a freshwater condition was 18 atm, which is at least 18 times larger than that of vacuum suction cups.
Similar results were achieved for submersion in saltwater and oil. They performed various experiments to explore the applications of their SMPs - for example, they used the adhesive to attach a hook to a wet wall. Once the SMP had adhered, they were able to hang a loaded backpack on the hook without experiencing any weakness in the adhesion.
"These findings will result in reusable high-strength adhesive fasteners for wet or submerged wall mounting," said Kim, who plans to commercialize his results through a start-up.
"The next step for this technology will be to further explore SMP adhesive systems to enable reversible adhesive grippers."
Research Report: Reversible underwater dry adhesion of a shape memory polymer
UH researchers report new class of polyethylene catalyst
Houston TX (SPX) Jan 28, 2019
A team of chemists from the University of Houston has reported the discovery of a new class of catalyst to produce ultra-high-weight polyethylene, a potential new source of high-strength, abrasion-resistant plastic used for products ranging from bulletproof vests to artificial joints. The nickel-based catalyst is described in a paper published Friday, Jan. 25, in Nature Communications. "This is a completely new class of catalysts that can produce ultra-high-weight polyethylene," said co-auth ... read more
|The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us.