TiO_2纳米粉末显现潜在指纹研究

Studies on development of latent fingerprint using TiO_2 nano-powder

目的建立并比较了TiO2纳米粉末与常规粉末的显现效果。方法使用配粉、色素、疏水性物质对TiO2纳米粉末进行改性,并通过正交实验设计法对综合改性条件进行优化。结果与普通粉末相比,TiO2纳米粉末由于粒度上的优势,具有显现细节特征多、背景表面无粘粉、显现陈旧指纹能力强等优点;通过添加配粉、色素、疏水性物质等改性剂,可以增加TiO2纳米粉末的流散性、扩大粉末与客体背景的反差并提高了其显现潮湿客体的能力。最佳改性方案为使用20%的色素、5∶2的配粉比例以及十六胺做疏水性物质。结论TiO2纳米粉末能更有效显现非渗透性客体表面上的潜指纹。

Objective To improve the technique of powder method for detecting of latent fingerprint. Method TiO2 nano-powder was compared to conventional powders, and improved by adding pigment, hydrophobic materials or mixed with other powder. Result The improving method was optimized through orthogonal design optimization method. TiO2 nano-powder can develop more details, produce less background and be better with the old fingerprints, because of its good granularity. When combined with pigment, hydrophobic materials or mixed with other powders, it will result in good fluidity, better contrast and high ability in developing latent fingerprints on moist surface. The optimum TiO2 nano-powder could be obtained with 20% pigment, 5 ： 2 assistant powder and 1-hexadecylamine as a hydrophobic agent. Conclusion TiO2 nano-powder is effective reagent for the development of latent fingerprints on the non-porous surface.