羧甲基纤维素钠和甲基纤维素在ZrO_2微粉上的吸附作用及其对悬浮体稳定性的影响

研究了ZrO2微粉自水中对羧甲基纤维素钠（CMC）和甲基纤维素（MC）的吸附作用及对ZrO2水悬浮作稳定性的影响．结果表明：（1）CMC的吸附等温线为Langmuir型，CMC可能以较为舒展的方式单层吸附于ZrO2。表面，由于有电性吸引作用在pH3．4时的极限吸附量较pH7．0时的略大；（2）MC的极限吸附量远大于CMC的，MC分子可能以线团状吸附，吸附层厚度可达14～56nm；（3）难较大浓度时MC比CMC更易于使ZrO2悬浮作稳定．

ADSORPTION OF SODIUM CARBOXYMETHYL CELLULOSE AND METHYL CELLULOSE ONTO ZrO_2 POWDERS AND EFFECT ON THE STABILITY OF ZrO_2 SUSPENSION

The adsorption of sodium carboxymethyl cellulose (CMC) and methyl cellulose (MC)onto the ZrO2 powders in aqueous solutions and the effect of the adsorption on the stability ofZrO2 suspension have been studied. The results show that (1) the isotherms of CMC are ofLangmuir type. The adsorption CMC molecules have an extended configuration under thenegative charges carried on the segments of the CMC molecules. The limiting adsorbed amountof CMC at pH 3.4 is larger than that at pH 7.0 because the attraction between positively chargedZrOz surface and negative CMC ions. (2) The limiting adsorbed amount of MC is much larserthan that of CMC, The adsorbed MC molecules have a coiled conformation, with a thickness ofthe adsorbed layer of 14-56nm depending on different pH. (3) At higher concentration of CMCand MC, the stability of the ZrO2 suspension is increased, and MC is better than CMC inenhancing the stability of the ZrO2 suspension.