Synthesis and characterization of triad based rigid mesogenic diols derived from hydroquinone and 4-hydroxybenzoic acid

591-596Triad based rigid mesogenic diols have been synthesized by four step synthesis method using protection-deprotection method. Hydroquinone and 4-hydroxy benzoic acid have been used as starting materials. Synthesized diols have been characterized by IR, 1H and 13C NMR, and mass spectroscopic methods. Thermal properties have been determined by thermo gravimetric analysis method and degree of crystallinity have been measured by wide angle X-ray technique. Substituted hydroquinones (methyl and chloro) have been used to study the effect of substitution on physical and thermal properties. Synthesis of rigid mesogenic diol monomer using p-hydroxy benzoic acid and hydroquinone is reported, which is a facile route. Hydrolysis of diacetate derivatives of rigid mesogenic diols is performed in good yields, even though two types of ester groups present in the same moiety, aromatic and aliphatic. The experimental results reveal that hydroquinone based rigid triad mesogenic diol have high thermal stability and degree of crystallinity as compared to methyl-and chloro-substituted rigid triad mesogenic diols

Synthesis and characterization of azoxy based mesogenic diols

359-362  Azoxy based rigid mesogenic diols have been synthesized using two steps. Phenol/cresol is used as starting material. Synthesized diols are characterized by IR, 1H and 13C NMR, and mass spectroscopic methods. Thermal properties have been determined by thermo gravimetric analysis method and crystallinity patterns have been obtained by wide angle X-ray diffractogram. Substituted phenol (methyl) is used to study the effect of substitution on physical and thermal properties of rigid azoxy mesogenic diol. The detailed characterization of azoxy based rigid diols is reported in this communication, which is highly useful for fundamental and applied research, particularly in liquid crystals and liquid crystalline polymers. The experimental results reveal that phenol based rigid mesogenic diols have high thermal stability and degree of crystallinity than methyl substituted rigid mesogenic diols

Chitosan-based bionanocomposites for biomedical application

Natural polymers have greatly impacted the advancement of modern medicine. Natural polymer-based biomaterials are biodegradable. A significant advantage of natural polymers is that they can be broken down and removed from the body after they have served their function. A wide range of novel biomaterials from natural polymers has been investigated to meet new challenges in medical science. Chitosan is one of the natural polymers which have been widely used in the biomedical field. Nanotechnology is one of the most popular areas of current research. In the area of nanotechnology, polymer and metal/metal oxide nanoparticle matrix-based nanocomposites have generated a significant amount of attention in the recent literature. These bionanocomposites have wide-ranging applications in drug delivery and tissue engineering. This paper discusses polymer-metal/metal oxide nanoparticle matrix-based nanocomposite biomaterials and their applications in the biomedical field-that is, drug delivery and tissue engineering applications

Characterization of a Novel Nanocomposite Film Based on Functionalized Chitosan–Pt–Fe3O4 Hybrid Nanoparticles

The development of organic—inorganic hybrids or nanocomposite films is increasingly becoming attractive in light of their emerging applications. This research focuses on the formation of a unique nanocomposite film with enhanced elasticity suitable for many biomedical applications. The physical property measurement system and transmission electron microscopy were used to analyze Pt–Fe3O4 hybrid nanoparticles. These nanohybrids exhibited magnetic effects. They were further exploited to prepare the nanocomposite films in conjunction with a chitosan-g–glycolic acid organic fraction. The nanocomposite films were then examined using standard techniques: thermogravimetric analysis, X-ray diffraction, Fourier transform infrared spectroscopy, and atomic force microscopy. Tensile strength testing demonstrated a significantly greater elastic strength of these nanocomposite films than pure chitosan films. The water absorption behavior of the nanocomposites was evaluated by measuring swelling degree. These nanocomposites were observed to have substantially improved physical properties. Such novel nanocomposites can be extended to various biomedical applications, which include drug delivery and tissue engineering