University of North Texas

Tong Cai

Zhibing Hu

Manuel Marquez

Arup Neogi

Ezekiel Walker

Jun Gao

Gang Huang

Jun Zhou

Bo Zhou

Shijun Tang

Xihua Lu

Tunable polymer-based sonic structures ('TuPSS') are made up of sonic structures and polymers. The TuPSS has three general requirements: a) The sonic structure is composed of one or materials engineered to behave as a lens, filter, cloak, or dampener; b) Stimulus sensitive polymer is incorporated into the sonic structure; and c) The actuation of the polymer tunes the acoustic behavior of the structure in a predictable manner. The tunable polymer-based sonic structures utilize stimuli-driven physical properties of the polymers in these acoustic structures to produce a stimulus driven, or tunable, sonic structure or device. The sonic structures actively modulate mechanical vibrations that propagate through the structures, but are passive in that they do not produce mechanical vibrations. The stimuli for the structures include electric, magnetic, electromagnetic, chemical, thermal, and shaking/orientation.

Tunable polymer-based sonic structures

The compositions of hydrogel colloidal crystals are made from mixing an aqueous suspension of poly-N-isopropylacrylamide ('PNIPAM')-co-allylamine microgels with dichloromethane, forming a PNIPAM-co-allylamine/dichloromethane mixture. The PNIPAM-co-allylamine/dichloromethane mixture is incubated for a period of time at a given temperature, forming the colloidal crystal material. The colloidal crystals can be stabilized by diffusing a glutaric dialdehyde solution into the colloidal crystal material. The concentration of polymer matrix microgels can determine the orientation of random or columnar crystals.

Synthesis of columnar hydrogel colloidal crystals in water-organic solvent mixture

A method is disclosed for creating hydrogels with ordered crystalline structures that exhibit a characteristic colored opalescence. In addition to the unique optical properties, these materials contain a large amount of water in their crosslinked networks. The manufacturing processes include synthesizing monodispersed hydrogel nanoparticles containing specific reactive functional groups, self-assembly of these particles to form a crystalline structure, and subsequent crosslinking neighboring spheres to stabilize the entire network. Polymerizing a hydrogel monomeric composition around the crystalline structure can enhance the mechanical strength. The resulting network is dimensionally and thermodynamically stabile under various pH and temperature conditions. The color and volume of these crystalline hydrogel networks can reversibly change in response to external stimuli such as temperature, pH and other environmental conditions. These new materials may lead to a variety of technological and artistic applications, ranging from sensors, displays, controlled drug delivery devices, jewelry and decorative consumer products.

Synthesis, uses and compositions of crystal hydrogels

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Denton, TX, United States of America

Tong Cai