| 摘要 |
<p>Test materials for determining the density or osmolarity of a liq. sample comprises dye-filled microcapsules whose walls consist of an osmotically rupturable semipermeable polymer membrane. The dye-filled microcapsules are pref. polyamide capsules produced by interfacial polycondensation of a polyamine with a polyfunctional acyl halide in a soln. contg. the dye (esp Evans blue.) The density of the encapsulated soln. should be greater than that of the liq. to be tested. The materials can be used, e.g., in brewing, urine analysis and water purification. The microcapsules release the dye when immersed in the test liq., and the extent to which the dye is release is a function of the osmolarity of the liq. The results can be read off simply by comparison with a colour chart or by photometry.</p> |
