Fubini B, Bolis V, Cavenago A, Volante M
Department of Inorganic, Physical and Material Chemistry, Faculty of Pharmacy, University of Turin, Italy.
Scand J Work Environ Health. 1995;21 Suppl 2:9-14.
The effect of grinding, heating, and etching was investigated on polymorphs of silicon dioxide exhibiting different biological responses. Diatomaceous earths were converted into cristobalite at 1000 degrees C. Dusts obtained by grinding crystalline minerals exhibited different micromorphology and a propensity to originate surface radicals which decrease in the sequence cristobalite --> quartz --> coesite --> stishovite. The production of surface radicals was suppressed by grinding in the presence of water. Thermal treatments selectively quenched the radicals and decreased surface hydrophilicity. Quartz treated with aluminum lactate exhibited higher surface acidity when compared with pure quartz, with a reduction in fibrogenicity. Etching by hydrofluoric acid smoothed the particles with loss of specific surface. Adsorption of water on three cristobalite dusts of different origin (ground mineral, ex-diatomite, heated quartz) indicated a loss in heated quartz (1300 degrees C) that was relatable to the corresponding reduction in fibrogenicity.
研究了研磨、加热和蚀刻对表现出不同生物学反应的二氧化硅多晶型物的影响。硅藻土在1000℃时转变为方石英。通过研磨结晶矿物获得的粉尘呈现出不同的微观形态，并且有产生表面自由基的倾向，其产生顺序为方石英>石英>柯石英>斯石英。在有水存在的情况下研磨可抑制表面自由基的产生。热处理可选择性地淬灭自由基并降低表面亲水性。与纯石英相比，用乳酸铝处理的石英表现出更高的表面酸度，同时纤维化能力降低。用氢氟酸蚀刻使颗粒表面光滑，比表面积减小。不同来源（研磨矿物、硅藻土、加热石英）的三种方石英粉尘对水的吸附表明，加热石英（1300℃）中的吸附损失与相应的纤维化能力降低有关。
