Applications of melting gels

Abstract

Hybrid organic-inorganic gels and glasses have been studied for many years for a variety of applications. Using the sol–gel process, it is possible to prepare silica-based hybrid gels that are rigid at room temperature, but soften and flow around 110 °C. This softening behavior has been called melting, even though it is not melting in a thermodynamic sense. Instead, the ability to flow is an indication that the material is not entirely cross-linked. In fact, some melting gels show glass transition behavior at temperatures below 0 °C. However, once these so-called melting gels have been heated at around 160 °C for 24 h, they no longer show the ability to soften. With an interest in using these materials for sealing microelectronics, their physical properties have been measured. In addition, their hydrophobicity, adhesion and electrochemical response have been evaluated in corrosive environments. It is also found that melting gels have been imprinted with good fidelity, and that gold nanoparticles maintain their plasmonic resonance when dispersed in melting gels. Finally, melting gels have been deposited by electrospraying to produce a variety of textures.