Rani, Joseph(Department of Polymer Science and Rubber Technology, November 8, 2006)
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Abstract:
Copper doped methylene blue sensitized poly(vinyl alcohol) (MBPVA)–acrylamide films were fabricated to improve the
storage life of recorded gratings. The films were fabricated using gravity settling method and the copper chloride
concentration was optimized as 3:18 10 3 mol/l for a dye concentration of 6:2 10 4 mol/l. The gratings recorded on the
optimized film constitution could be stored for months with stable diffraction efficiency (24%) without any chemical or
thermal fixing techniques. The resolution of the material is found to be unaffected with the addition of copper chloride.
Sudha Kartha, C; Nimmi, K P; Sreekumar, K; Rani, Joseph; Pramitha, V(Wiley Online Library, January 7, 2012)
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Abstract:
Holographic grating with good storage
life in poly(vinyl alcohol) based photopolymer film, prepared
by gravity settling method, with reduced concentration
of the dye was found to give good diffraction
efficiency without crosslinking. The material was found
to show good diffraction efficiency and sensitivity (75%
diffraction efficiency at exposure energy of 80 mJ/cm2).
The shelf life of the photopolymer solution could be
improved by storage at a temperature 4 C in refrigerator
Description:
Journal of Applied Polymer Science, Vol. 125, 1238–1243 (2012)
Rani, Joseph(Indian Academy of Sciences, February 24, 2003)
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Abstract:
Significant results of our experimental investigations on the dependence of pH on real time
transmission characteristics on recording media fabricated by doping PVC with complexed methylene blue
are presented. The optimum pH value for faster bleaching was found to be 4 . 5. In typical applications, the
illumination from one side, normal to the surface of this material, initiates a chemical sequence that records
the incident light pattern in the polymer. Thus direct imaging can be successfully done on this sample. The
recorded letters were very legible with good contrast and no scattering centres. Diffraction efficiency
measurements were also carried out on this material.