采用胶体化学法制得稳定的SnO_2纳米粒子水溶胶．在LB膜槽内，用膜天平考察了溶胶在陈化和匀速压缩过程中，气—液界面表面压力的变化情况，并用布儒斯特角显微镜（BAM），直接观察了陈化过程中界面胶体粒子的自由密堆积成膜过程，和匀速压缩过程中界面胶体粒子的压缩成膜过程，结果发现，新制（或刮净后）的溶胶表面处于亚稳态，而久置的溶胶表面处于稳定状态，并且溶胶气—液界面的纳米波粒，可通过陈化和压缩，密堆积成固态和类固态膜． The colloidal chemistry was used to prepare stable SnO_2 nanoparticle hydrosol. In the LB membrane tank, the surface pressure of the gas-liquid interface during the aging and uniform compression of the sol was examined by using a film balance. Using a Brewster angle microscope (BAM), the interface of the aging process was directly observed It is found that the sol surface of the new (or scraped) sol is in a metastable state and the surface of the long sol is stable State, and sol gas-liquid interface of nano-particles, through aging and compression, closely packed into solid and solid-like film.