首页 | 本学科首页   官方微博 | 高级检索  
     检索      


The Effects of Polymer Pigmentation on Fingermark Development Techniques
Authors:Simon R Bacon MPhil  Jesus J Ojeda PhD  Rory Downham BSc  Vaughn G Sears BSc  Benjamin J Jones PhD  CPhys
Institution:1. Experimental Techniques Centre (ETCbrunel), Brunel University, , Uxbridge, Middlesex, UB8 3PH U.K;2. Chemistry, Home Office Science ‐ Centre for Applied Science and Technology (CAST) Home Office, Woodcock Hill, , Sandridge, St. Albans, AL4 9HQ U.K
Abstract:The effectiveness of latent fingerprint development techniques is heavily influenced by the physical and chemical properties of the deposition surface. The use of powder suspensions is increasing for development of prints on a range of surfaces. We demonstrate that carbon powder suspension development on polymers is detrimentally affected by the presence of common white pigment, titanium dioxide. Scanning electron microscopy demonstrates that patches of the compound are clearly associated with increased levels of powder adhesion. Substrates with nonlocalized titanium dioxide content also exhibit increased levels of carbon powder staining on a surface‐wide basis. Secondary ion mass spectrometry and complementary techniques demonstrate the importance of levels of the pigment within the top 30 nm. The association is independent of fingermark deposition and may be related to surface energy variation. The detrimental effect of the pigment is not observed with small‐particle reagent (MoS2 SPR) or cyanoacrylate (superglue) fuming techniques that exploit different development mechanisms.
Keywords:forensic science  latent fingerprints  polymers  powder suspension  surface chemistry  carbon
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号