摘要 |
<p>Present proposals to use perfluorocarbons as a medium to suspend glass particles presents the problem of aggregation of the particles within the suspending medium. Overcoming this problem requires careful particle sizing and density matching techniques. An additional disadvantage of the large scale use of perfluorocarbons is their contribution to global warming. The inventor has realised that by replacing perfluorocarbons with the more environmentally friendly fluorinated ethers such as hydrofluoroethers or hydrofluoropolyethers a long lasting suspension of glass particles can be achieved without the need for such rigorous particle sizing or density matching processes.</p> |