Abstract: Biologically active agents to be encapsulated are continuously blended with a starchy material and water, subjected to high-shear mechanical action at a temperature above the gelatinization temperature of starch, and continuously recovered as an insolubilized matrix of starch that entraps discontinuous domains of the agent. Alternatively, the core material to be encapsulated is added and blended with the aqueous dispersion of starch after the starch and water have been subjected to an elevated temperature sufficient to gelatinize the starch. Rate of release of agents to the environment can be controlled by preselecting a set of conditions related to various processing parameters. Encapsulation of biologically active compositons provides protection against degradative environmental conditions, improves safety in handling, and slows the release of such compounds to the surrounding medium.

Abstract: Chemical biological agents to be encapsulated are blended into an aqueous dispersion of an unmodified starch comprising about 5% to about 25% by weight amylose. The dispersion, having an initial starch solids content of about 20% by weight, is characterized by completely disrupted starch granules and completely disassociated amylose molecules that are not significantly depolymerized. Subsequent drying is accomplished by reassociation of the amylose molecules which converts the dispersion into a protective matrix and binds the agents within the interstices of the reassociating starch chains. Rate of release of agents to the environment can be altered by varying the proportion of amylose in the starch. Encapsulation of biologically active compositions provides protection against degradative environmental conditions, improves safety in handling, and slows the release of such compounds to the surrounding medium.

Abstract: Crosslinked starch is reacted with an epihalohydrin in the presence of a strong acid catalyst to produce the 3-halo-2-hydroxypropyl ether. Substitution of the halogen with nitrogen-containing compounds enables the preparation of novel water-insoluble cationic, anionic, and chelating starch ethers, as well as starch ethers having degrees of substitution heretofore unattainable in the prior art.

Abstract: An insoluble alkali metal-magnesium starch-xanthate composition is prepared which is capable of removing most heavy metal ions from aqueous solutions. Concentrations of heavy metal ions obtained in several industrial effluents were reduced to below the most stringent aqueous discharge limits.

Abstract: An insoluble alkali metal-magnesium starch-xanthate composition is prepared which is capable of removing most heavy metal ions from aqueous solutions. Concentrations of heavy metal ions contained in several industrial effluents were reduced to below the most stringent aqueous discharge limits.

Abstract: An insoluble-starch-xanthate composition is prepared which is capable of removing most heavy metal ions from aqueous solutions. Concentrations of heavy metal ions contained in several industrial effluents were reduced to below the most stringent aqueous discharge limits.

Abstract: Concentrations of undesirable heavy metals in industrial wastewater are reduced to below or very close to the most stringent aqueous discharge limits. This is accomplished by forming an insoluble metal-polyelectrolyte complex which can be easily and economically removed from the effluent.