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Published byMarianna Parker Modified over 8 years ago
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Saratov State University named after N.G. Chernyshevsky D.A. Rudenko and A.B. Shipovskaya
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BRIEF ANNOTATION The optical activity of chitosan films in the form of polysalt (chitosan acetate) and polybase was studied. The specific optical rotation [ α ] of all our films was negative. The absolute values of [ α ] of polybasic chitosan films was by an order of magnitude higher than that for polysaltic films. A dependence of [ α ] on the orientation angle of the sample relative to the direction of the polarization vector of the incident light beam in the plane perpendicular to this beam was established. Specific optical rotationindicatrices of the chitosan films of both chemical forms were plotted.
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Structural formula of chitosan Properties Biocompatibility with human tissues Biological and optical activity biodegradability Digestibility of the body, the properties of autologous Annually renewable raw material base
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Objects of research: We used a thin film of chitosan in saline (C-) and the main (O-) forms The reagent is a chemical reaction C- → O-form of chitosan: 1Н NaOH С-form О-form The solvent used was 2% aqueous acetic acid
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Research methods The optical activity was recorded on two automatic spectropolarimeters: PolAAr 3001 (Optical Activity Ltd, England), within the wavelength range of = 300–600 nm, T = 22±2ºС. The experimental conditions were standard, and the measurement error of the rotation angles did not exceed 0.002 o. The specific optical rotation [ ] (deg ml dm -1 g -1 ) was calculated by the following formula:, where α is the measured angle of optical rotation of the film sample, in degrees; is the optical path length, dm; and is the density of the film material, g/cm-3
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Curves ORD films of chitosan in the C- and O-forms Figure 1. ORD curves for CTS films in salt (1) and basic (2) form. The moisture content of the film samples was 22 2 (1) and 12 1 wt.% (2). Vertical bars show the variation range of [ ] values for different orientation angles of the film sample. С-form O-form
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Taking into account the fact that chitosan film and on the basis thereof characterized by structural and compositional heterogeneity amount measuring α performed over the entire surface of the film sample. The above discussed experiments varying range of values [α] at different orientation angles film sample shows vertical bars. Angular dependence (indicatrix) specific optical rotation film СTS the orientation angle of the sample relative to the direction of the polarization vector of the incident light beam in a plane perpendicular to the given beam in polar and Cartesian coordinates are shown below.
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Polar coordinates Cartesian coordinates Figure 2. The dependence of the specific optical rotation [α] the angle of rotation of the sample polar (a, b) and Cartesian coordinates (c, d) films CTS in the form of polisoli (acetate) (a, b), poliosnovaniya (in g) at α = 365 (1) 405 (2) 436 (3), 546 (4) and 589 nm (5). (а) (d)(d) (b)(b) (c)(c) Indicatrices specific optical rotation С-form O-form
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