| 摘要 |
Controlled release compositions are made by a distillation method to include chemical impregnants (such as animal repellants, pesticides, herbicides, fungicides, plant growth stimulants, perfumes and deodorizers, fertilizers, and drugs) in biodegradable, microporous structures. Each microporous structure collapses upon drying but swells upon rewetting to allow the impregnant entrapped in it to diffuse from the structure. Never-dried wood pulp is a particularly desirable microporous structure because it has large pores initially, a large surface area initially, and demonstrated swelling capability. The method is particularly useful when the impregnant is insoluble in the fluid initially within the microporous structure and when the solvent for the impregnant is immiscible with that fluid.
|
