Guar gum improved electrolyte compatibility. These changes in properties result in increased use in different fields, like textile printing, explosives, and oil-water fracturing applications. Guar molecules have a tendency to aggregate during the hydraulic fracturing process, mainly due to intermolecular hydrogen bonding. These aggregates are detrimental to oil recovery because they clog the fractures, restricting the flow of oil. Cross-linking guar polymer chains prevents aggregation by forming metal – hydroxyl complexes. The first crosslinked guar gels were developed in the late ‘60’s. Several metal additives have been used for crosslinking, among them are chromium, aluminum, antimony, zirconium, and the more commonly used,
Sol–gel process for a variety of medical applications. A sol–gel processed alumina can be used as a carrier for the sustained delivery of drugs and as an established wound healer. A marked decrease in scar size was observed because of the wound healing composite including sol–gel processed alumina. A novel approach to thrombolysis treatment is possible by developing a new family of injectable composites: plasminogen activator entrapped within alumina. Sol–gel process In materials science, the sol–gel process is a method for producing solid materials from small molecules. The method is used for the fabrication of metal oxides, especially the oxides of silicon