| Carbon nanotubes (CNTs) are a kind of potential laser protecting materialowing to their good optical limiting effect. To make them work effectively, CNTsmust be homogeneously dispersed into some matrices. However, up to now, thematrices are used to be kinds of liquid solution which make it difficult for practicaluse. Inorganic glass matrix has excellent stability, good transparency, and high laserdamage threshold. Therefore, it could be an ideal matrix for encapsulating of CNTs.Fulfilling of this idea would be helpful for the realization of CNTs'optical limitingeffect. The structure, properties and optical limiting mechanism of CNTs, togetherwith its potential application in the field of laser protection and the problems thatwill be meet before practical use, are reviewed in this paper. CNTs were successfullyintroduced into inorganic matrix to produce composites with both durability andoptical limiting effect by sol-gel technique, which were carried out measurements ofspectral characterization, microscope and pore structure. The best composition andprocessing conditions are obtained. The thermal and laser stability of the compositeswere studied by means of tracing the evolution of change of its composition andstructure during the heat and laser bombard process. The optical limiting behaviorsof CNTs composites at both wavelength of 532nm and 1064nm were studied andcompared with its DMF solution. The results show that under the ideal sol-gel conditions CNTs could behomogeneously dispersed into silica xerogel matrix, and its structure will not be hurtin the process. Sol-gel technique is an useful and effective method of producingCNTs/silica composite. The encapsulated CNTs have good heat stability in thecomposite, but show poor stability under the strong laser irradiation. The results alsoshow CNTs have good optical limiting behavior in both silica xerogel matrix andDMF solution, and their optical limiting effect are improved after being introducinginto solid state matrix.
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