Development and Characterization of Calcium Based Biocomposites Using Waste Material (Calcite Stones) for Biomedical Applications

Calcium-based biocomposite materials have a pivotal role in the biomedical field with their diverse properties and applications in combating challenging medical problems. The study states the development and characterization of Calcium-based biocomposites: Hydroxyapatite (HAP), and PVA-Gelatin-HAP films. For the preparation of Calcium-based biocomposites, an unconventional source, the waste material calcite stone, was used as calcium raw material, and by the process of calcination, calcium oxide was synthesized. From calcium oxide, HAP was prepared by chemical precipitation method, which was later added in different proportions to PVA-Gelatin solution and finally dried to form biocomposite films. Then the different properties of PVA/Gelatin/HAP composite, for instance, chemical, mechanical, thermal, and swelling properties due to the incorporation of various proportions of HAP in PVA-Gelatin solution, were investigated. The characterization of the HAP was conducted by X-ray Diffraction Analysis, and the characterization of HAP-PVA-Gelatin composites was done by Fourier Transform Infrared Spectroscopy, Thermomechanical Analysis, Tensile test, Thermogravimetric Differential Thermal Analysis, and Swelling Test. The produced biocomposite films might have applications in orthopedic implants, drug delivery, bone tissue engineering, and wound healing.

Reclamation of Lithium Cobalt Oxide from Waste Lithium Ion Batteries to Be Used as Recycled Active Cathode Materials

Waste laptop batteries (Type-Lithium ion) have been collected and manually dismantled in the current work. Active electrode materials were scraped off from the copper current collector and polyethylene separators. The aluminum current collectors were found to be severely damaged and attached with the electrode material. It was treated with NaOH later to be recovered as Al2O3. The leaching of LiCoO2 was done by 3 M HCl aided by 5% H2O2 at 60°C from the scraped active electrode materials (LiCoO2 and graphite) leaving the graphite completely. Co was precipitated as hydroxide by the addition of NaOH and later converted to Co3O4. The remaining solution was treated with saturated Na2CO3 to acquire Li2CO3 as crystalline precipitate with high purity. The recovery of Co and Li was 99% and 30%, respectively. Co3O4 and Li2CO3were mixed in stoichiometric proportions and calcined around 950°C with air supply to achieve LiCoO2 successfully.

Synthesis and Characterization of Copper-Zinc-Tin-Sulfide(CZTS)Thin Film Absorber Layer for Solar Cell Application

Copper zinc tin sulfide(CZTS)thin film was synthesized on soda lime glass substrate by using spin coating method.The synthesized CZTS thin film showed maximum absorption coefficient of 0.193×104 cm-1 and maximum extinction coefficient of 0.011.The direct optical band gap,Urbach energy and steepness parameter of the synthesized CZTS thin film were 1.52 eV,0.52 eV and 0.05 respectively.The CZTS thin film was found to be polycrystalline tetragonal in nature.The scanning electron microscopy(SEM)revealed that the texture structure was formed for the CZTS thin film.

Determination of Bed Void Fraction from Fixed Bed Breakthrough Curve

Accurate physical and chemical properties of adsorbents are required for the efficient design of fixed bed adsorbers. The bed void and particle void are significant physical properties. One of the experimentally determination technique for the bed void is a breakthrough curve method. In the present paper, experimental conditions for determining the bed void from breakthrough curve were investigated because complex conditions are required. The values of bed void were determined from theoretical elution curve at the point of c/c0 = 0.5 under the condition of negligible amount adsorbed. The bed void value determined from elution curve was clearly affected by particle void and fluid velocity, and regarded as ＂apparent＂ bed void values. For large porosity particles, it was difficult to determine the true bed void value due to the effect of penetration into macro pores. Then, the bed void fraction can be determined safely from breakthrough curve when particles possessing small particle void are used.

Isolation of Bulk Amount of Piperine as Active Pharmaceutical Ingredient (API) from Black Pepper and White Pepper (<i>Piper nigrum</i>L.)

In the pharmaceutical world the majority of the active pharmaceutical ingredients (API) have been obtained from the natural products. Piperine is such naturally occurring alkaloid which can be considered as major bioactive phytochemical having broad spectrum of pharmacological activities. It is obtained from the most valuable ethnomedicinal spices peppercorns i.e. black pepper and white pepper, which are the fruits of the Asian vine Piper nigrum L. Because of the widespread traditional uses of this medicinal compound, present article reveals a simple and effective isolation method of bulk piperine. The novelty of this investigation is to provide an idea for utilizing such natural method of large scale commercial piperine production as API drug in spite of chemical synthesis. Piperine was isolated in a pure crystal form and characterized by its melting point, X-Ray diffraction (XRD) studies and spectral data, including two-dimensional nuclear magnetic resonance (2D-NMR) spectroscopy. Chromatographic techniques like Thin Layer Chromatography (TLC) and High Performance Liquid Chromatography (HPLC) were applied to determine the purity of the yielded piperine. It was found that piperine yield from black pepper was within 2.5% - 3.0% and from white pepper within 4.0% - 4.5% and the purity of the yielded piperine was found to be up to 98.5% for black pepper and 98.2% for white pepper. Considering this yield value and purity it is indicated that, such effective isolation method can be successfully utilized for industrial large-scale production commercially. According to the result, it can be claimed that, as a natural product the isolated piperine can also be utilized as API drug like other expensive chemically synthesized piperine in different drug formulation.

Preparation and Characterization of Raw and Chemically Modified Sponge-Gourd Fiber Reinforced Polylactic Acid Biocomposites

This research work has been undertaken to fabricate environmentally friendly biocomposites for biomedical and household applications. Sponge-gourd fibers (SGF) obtained from Luffa cylindrica plant were chemically treated separately using 5 and 10 wt% NaOH, acetic anhydride and benzoyl chloride solutions. SGF reinforced polylactic acid (PLA) biocomposites were fabricated using melt compounding technique. Surface morphological, structural, mechanical and thermal properties, as well as antibacterial activities of raw and chemically modified SGF reinforced PLA (SGF-PLA) composites were characterized by field emission scanning electron microscopy, Fourier transform infrared spectrometry, X-ray diffractometry, universal testing method, thermogravimetry, and Kirby-Bauer agar diffusion method, respectively. Surface morphology indicates that after treatment of fibers, the interfacial adhesion between PLA and fibers is improved. X-ray diffractometry result shows that chemical treatment of fibers improves the crystallinity and exhibits new chemical bond formation in the composites. After chemical treatment, compressive strength of the composites is found to increase by 10% - 35%. The thermal stability of the treated fiber reinforced composites is also found to increase significantly. The composites have no antibacterial activities and no cytotoxic effect on non-cancer cell line. Soil burial test has confirmed that the composites are biodegradable. Benzoyl chloride treatment of fibers shows superior mechanical properties and enhances thermal stability among the composites.