Photothermal imaging

The manipulator is precise enough to position the photothermal camera over each 100x100 mm zone of the tubesheet. The photothermal image of the entire zone is generated directly by the inspection head. 

Figure 1 (A) Spatial dependence of a single-frequency (harmonically driven) thermal wave. Frequency 20.0 Hz, diffusivity 1 X lO m s L (B) Spatial dependence of the thermal wave observed at various times after application of a heat pulse. Diffusivity 1 xIO m s L The instantaneous phase (j> — cot. (Reprinted from Power JF (1993) Scanning probes III Photoacoustic and photothermal imaging. In Morris MD (ed.) Microscopic and Spectroscopic Imaging of the Chemicai State, pp. 255-302. New York Dekker, courtesy of Marcel Dekker, Inc.)...

Anisotropy in thermal diffusivity provides the basis for a novel and interesting photothermal imaging method. Fibrous materials and crystals, for example, may have a preferred axis for heat conduction. In materials that have been subjected to tensile loading, an enhanced thermal conductivity may lie along the stretch axis. 

Microstructural changes produced in mechanically deformed metals produce significant variations in their thermal properties, which can be detected using photothermal imaging. 

Photothermal imaging has also found applications in the study of practical industrial materials, including fibers, ceramics, and composites, where the depth dependence of the recovered image may be useful in identifying surface features due to mechanical or oxidative processes, or subsurface defects and delamination. 

Koulikov, S. G., and Dlott, D. D. (2000). Effects of Energetic polymers on laser photothermal imaging materials. J. Imaging Sci. Technol. 44, 111-119. 

Brusiuchkin, A. V. Nedosekin, D. A. Galanzha, E. I. Vladimirov, Y. A. Shevtsova, E. F Proskumin, M. A. Zharov, V. P Ultrasensitive label-free photothermal imaging, spectral identification, and quantification of cytochrome c in mitochondria, live cells, and solutions. J. Biophotonics 2010, 3, 791-806. 

Figure 7 New photothermal camera versus penetrant testing on a crack (width 5 pm) at the surface of Fig 4. part The large arrow shows that the PT indication almost extinguishes at thinner width (approx. I pm) locations along the crack the photothermal signal does not. The bottom little arrow indicates a place where the crack splits in two, which is not revealed on the PT image because of the spreading of the penetrant liquuid.

Water soluble starch capped nanoparticles proved to be efficient non-cytotoxic bactericidal agents at nanomolar concentrations. The investigation also suggested that starch capped CuNPs have great potential for use in biomedical applications such as cellular imaging or photothermal therapy. 

Huang, X., El-Sayed, I.H., Qian, W. and El-Sayed, M.A. (2006) Cancer cell imaging and photothermal therapy in the near-irrfrared region by using gold nanorods. Journal of the American Chemical Society, 128, 2115-2120. 

Photothermal Spectroscopy Methods for Chemical Analysis. By Stephen E. Bialkowski Element Speclatlon in Bioinorganic Chemistry. Edited by Sergio Caroli Laser-Enhanced Ionization Spectrometry. Edited by John C. Travis and Gregory C. Turk Fluorescence Imaging Spectroscopy and Microscopy. Edited by Xue Feng Wang and Brian Herman... 

Combinatorial methods were also applied in the discovery of new catalysts for the low-temperature oxidation213 and oxidative dehydrogenation of propane.214 A 144-member catalyst library was screened by photothermal deflection spectroscopy and mass spectrometry to find the most active compositions of V-Al-Nb and Cr-Al-Nb oxides for the oxidative dehydrogenation of ethane.215 The ternary combination V(45)-Sn(45)-Mo(10)-O selected by laser-induced fluorescence imaging gave much higher yield than did V205 in the selective oxidation of naphthalene to naphthoquinone.216... 

The ammonia or amine photothermally liberated from a cobalt(III) complex can be used to crosslink a carbonyl-containing polymer. One such complex is (120), which can be used in a photoresist composition where the non-crosslinked polymer is dissolved away, leaving a negative image in hardened polymer.246... 

Prashant KJ, Huang X, El-Sayed IH, El-Sayed MA. Noble metals on the nanoscale Optical and photothermal properties and some applications in imaging, sensing, biology and medicine. Acc Chem Res 2008 in press. 

Larson TA, Bankson J, Aaron J, Sokolov K. Hybrid plasmonic magnetic nanoparticles as molecular specific agents for MIRI/optical imaging and photothermal therapy of cancer cells. Nanotechnology 2007 18 325101-9. 

Photoablation of Copolymers, Other workers have also investigated the phenomenon of polysilane self-development. Zeigler and co-workers (13) have studied the self-development of a number of polysilane homo- and copolymers and found that self-development eflSciencies increase with the size of substituents. They also suggested that the material removal process for alkyl-substituted poly silanes at low fluences (<50 mj/cm per pulse) is predominantly photochemical rather than photothermal. By using a 1 1 copolymer, poly(methyl-n-propylsilane-co-isopropylmethylsilane), images were generated by excimer laser exposure at 248 nm. 

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