蒙脱石作为尿素缓释基质的试验研究

EXPERIMENTAL STUDY ON USING MONTMORILIONITE AS SLOW RELEASING MATRIX FOR UREA

采用一定的方法可使尿素进入蒙脱石层间，形成蒙脱石尿素夹层复合体。在一定范围内，随着尿素夹入量的增加，复合体的晶面间距（d001）逐渐增大。与钙基蒙脱石-尿素夹层复合体相比，钠基蒙脱石-尿素夹层复合体的尿素夹入量较大，并且置于土壤后尿素分子释放较快。蒙脱石-尿素夹层复合体在尿素的不断释放过程中，其出d001值逐渐减小并趋向于恢复到夹层作用前蒙脱石的d001值。蒙脱石可望在农业上作为尿素缓释基质。

In a certain way urea molecules can be made to enter into the crystal layers of montmoril-lonite to form montmorillonite-urea intercalati0n complex. With increasing urea, the d001 value ofthe montmorillonite-urea intercalation complex will increase gradually to some extent. In contrastto Ca-montmorillonite-urea intercalation complex, Na-montmorillonite-urea intercalation complexcontains a large quantity of urea(the maximum is about 3O% in weight)and urea molecules escapefrom the complex rapidly when it is buried in soil. The d001 value of the complex decreases gradual-ly and tends to be the original value when urea molecules release from the intercalation complex lit-tle by little. It is expected tbat montmorillonite can be used as urea for slow release n1atrix.