Cu^(2+)与硅酸、硅胶表面硅羟基的反应及其平衡常数

REACTION OF Cu^(2+) WITH SILICIC ACID AND SURFACE SILANOL GROUPS AND THEIR EQUILIBRIUM CONSTANTS

本文用铜电极法研究 Cu2 +和硅酸、硅胶表面硅羟基的反应及其平衡常数 ,结果是 :Cu2 ++H3 Si O4-Cu H3 Si O+4 K1 =5.0× 1 0 3Cu2 ++2 H3 Si O4-Cu(H3 Si O4) 2 β2 =6.1× 1 0 8Cu2 ++Sis- OH Sis- OCu++H+ Ks1 =2 .0× 1 0 -6Cu2 ++2 Sis- OH ((Sis- O) 2 Cu+2 H+ βs2 =2 .5× 1 0 -1

The reaction of Cu2 +with silicic acid and surface silanol groups of silica gel was studied by use of copper- ion- selective electrode at 2 5℃ in the 0 .1mol· l-1 KNO3 solution.The re- sults were: Cu2 ++H3 Si O4-Cu H3 Si O+4 K1 =5 .0× 10 3 Cu2 ++2 H3 Si O4-Cu(H3 Si O4) 2 β2 =6 .1× 10 8 Cu2 ++Sis- OH Sis- OCu++H+ Ks1 =2 .0× 10 -6 Cu2 ++2 Sis- OH (Sis- O) 2 Cu+2 H+ βs2 =2 .5× 10 -1 2