【摘要】 利用红外光谱、透射电镜和粒度分析等研究了聚乙二醇 (PEG)对纳米SiO2 表面性能及分散性的改进效果。通过砂芯拉伸强度的测定研究了纳米SiO2 的种类及用量对酯固化酚醛树脂粘结剂粘结强度的影响。结果表明 :经过PEG改性后的纳米SiO2 的表面羟基减少 ,粒子的分散程度提高 ;随着PEG浓度的增大 ,粒子的平均粒径先减小 ,后增大 ,在浓度为 0 .6 %时出现最小值。多孔形纳米SiO2 比球形的增强效果要好 ;随着纳米SiO2 用量的增加 ,砂芯的粘结强度先增大 ,后减小 ,在加入量为 0 .5 %左右时 ,出现峰值 ,强度增加 4 5 %。更多还原

【Abstract】 In this paper,the surface modification and dispersion of nano SiO 2 particles with PEG were studied by means of IR,TEM,and particle size analysis.The effect of the category and amount of nano SiO 2 particle on binding strength of the ester cured nano SiO 2/phenolic resin binder was also studied by means of the measurement of sand core tensile strength.The result showed that the hydroxy amount on the modified nano SiO 2 particle surface was reduced,and the particle dispersion was improved.With increasing of PEG concentration,the mean diameter of nano SiO 2 was first decreased,then increased.And with the 0.5% PEG the value reached a minimum.The result also showed the effect of porous nano SiO 2 is better than that of spherical nano SiO 2,with increasing of nano SiO 2 amount,the binding strength of sand core was first increased,then decreased, when the content of nano SiO 2 was about 0.5%,the binding strength of sand core was increased by 45%.更多还原