Spectrophotometers, X-ray

Microanalytical Service Ltd., Vancouver. The total Ca, Mg, P, Na, K, and Fe were determined by Dr. Carmen Mazuelos (Centro de Edafologia, CSIC, Sevilla, Spain) with a Perkin-Elmer Model 703 absorption spectrophotometer. The infrared spectrum of the lyophilized material was taken on KBr pellets (1 mg sample in 200 mg KBr) with a Perkin-Elmer Model 337 infrared spectrophotometer. X-ray diffraction analysis was carried out by Dr. Carmen Hermosin, Centro de Edafologia, in a Philips PW 1010 diffractometer using Ni-filtered, CuKoc, radiation operated at 30 kV and 20 mA, scanning speed of l°/min, time constant 2, and range of diffraction angles from 2 to 60°. 

Intrinsic viscosities of polyamic acid solutions were measured in DMF at 30 . Infared spectra of polyamic acid and polyimide were recorded on a Perkin-Elmer Model 137 Spectrophotometer. X-ray diffractograms were obtained using a Debye-Scherrer powder diffractometer with Ni-filtered copper K radiation(l.54) at 33CV. 

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