Barium hydrogen phosphate/gelatin composites versus gelatin-free barium hydrogen phosphate: Synthesis and characterization of properties
| Autor: | Manuela Elena Stir, Mazeyar Parvinzadeh Gashti, Matthias Burgener, Jürg Hulliger |
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| Rok vydání: | 2014 |
| Předmět: |
Thermogravimetric analysis
food.ingredient Scanning electron microscope Barium Compounds Crystal growth Gelatin Surfaces Coatings and Films Electronic Optical and Magnetic Materials law.invention Biomaterials Colloid and Surface Chemistry food X-Ray Diffraction law Spectroscopy Fourier Transform Infrared Thermal stability Microscopy Electrochemical Scanning Crystallite Crystallization Composite material Fourier transform infrared spectroscopy |
| Zdroj: | Journal of Colloid and Interface Science. 431:149-156 |
| ISSN: | 0021-9797 |
| Popis: | Recently, attention has been spent on crystal growth of phosphate compounds in gels for studying the mechanism of in vitro crystallization processes. Here, we present a gel-based approach for the synthesis of barium hydrogen phosphate (BHP) crystals using single and double diffusion techniques in gelatin. The composite crystals were compared with analytical grade BHP powder, single and polycrystalline BHP materials using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), scanning pyroelectric microscopy (SPEM), optical microscopy (OM), thermal gravimetric analysis (TGA) and X-ray diffraction (XRD). FTIR spectra showed surface adsorption of gelatin molecules by using BHP stacked sheets due to CH2 stretching, CH2 bending and amide I vibrations are found in a gelatin content of about 2% determined by dissolution. SEM shows various crystal morphologies of the BHP/gelatin composites forming bundled micro-flakes to irregular bundled needles and spheres different from gel-free crystals. The variety in morphology depends on the ion concentration, pH of gel as well as the method of crystal growth. SPEM investigation of BHP/gelatin aggregates revealed polar domains showing alteration of the polarization. Moreover, BHP/gelatin composite crystals showed a higher thermal stability in comparison with analytical grade BHP or/and BHP single crystals due to strong interactions between gelatin and BHP. The XRD diffraction analysis demonstrated that the single and double diffusion techniques in gelatin led to the formation of orthorhombic BHP. This study demonstrates that gelatin is a useful high molecular weight biomacromolecule for controlling the crystallization of a composite material by producing a variety of morphological forms. |
| Databáze: | OpenAIRE |
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