Application Of Composite Films Research Articles

Protein and Polysaccharide Recovery from Shrimp Wastes by Natural Deep Eutectic Solvent Mediated Subcritical Water Hydrolysis for Biodegradable Film.

Environmental pollution is a significant problem due to the improper disposal of plastics and shrimp shells outdoors. Therefore, the synthesis of biodegradable film from waste materials is highly important. The novelty of this research lies in the extraction of protein hydrolysates and chitosan from shrimp shells, as well as the fabrication of biodegradable film from these materials. In this study, the composite films were produced using the solution casting method. Moreover, the combined effect of ultrasound pretreatments (UPT) and natural deep eutectic solvents (NADES) was investigated as extraction media, to determine their potential impact on shrimp waste subcritical water hydrolysis (SWH). Shrimp shells were submitted to UPT in NADES solution, followed by SWH at different temperatures ranging from 150 to 230°C under 3MPa for 20min. Then, the physiochemical properties and bioactivities of the hydrolysates were assessed to determine their suitability for use in biodegradable packaging films. Additionally, the physiochemical properties and bioactivities of the resulting hydrolysates were also analyzed. The highest amount of protein (391.96 ± 0.48mg BSA/g) was obtained at 190°C/UPT/NADES, and the average molecular size of the protein molecules was less than 1000Da with different kinds of peptide. Overall, combined UPT and SWH treatments yielded higher antioxidant activity levels than individual treatments. Finally, the application of composite films was evaluated by wrapping fish samples and assessing their lipid oxidation. The use of higher concentrations of protein hydrolysates significantly delayed changes in the samples, thereby demonstrating the film's applicability.

Genipin cross-linked chitosan–PVA composite films: An investigation on the impact of cross-linking on accelerating wound healing

The applications of composite films in wound healing are immense, and the quest for suitable biomaterials drives research. Natural polymers lack mechanical strength; by cross-linking, their chemical nature can be changed through interlinking via intermolecular interactions rather than chemical bonds. This study explores the applications of cross-linked chitosan–polyvinyl alcohol–genipin films prepared using the solvent casting method. The cross-linked films were analyzed for their chemical structural changes, structural morphology, mechanical strength, and water retention capabilities. Comparative studies were performed with the un-crosslinked counterparts. Results indicated an increased tensile strength of 67.2% and improved water retention because of their compact structure. Further, Fourier-transform infrared spectroscopy confirmed that cross-linking occurred in the films, and scanning electron microscope micrographs showed that the films were uniform with a continuous morphology. Thereafter, an in vivo study was performed to assess the effectiveness of the films on wounds made on Albino Wistar rats. Histopathological analysis indicated quick fibroblast generation and angiogenesis using the cross-linked films, affirming their suitability for wound healing applications.

Flexible MXene/copper/cellulose nanofiber heat spreader films with enhanced thermal conductivity

Abstract To deal with the heat dissipation problem produced by a high integrated circuit, the preparation of heat spreaders with excellent heat transportation performance is increasing in demand. The Ti3C2 MXene sheets and copper particles were fully contacted with cellulose nanofibers by a high-speed mixer, and the composite film was prepared as a heat spreader under the action of the vacuum-assisted filtration. The MXene sheets are connected by the esterification of the carboxyl group in MXene and the hydroxyl group in cellulose nanofibers to form a chemical bond and consist of the main skeleton of the composite film. Due to the synergistic effects of MXene and copper particles, the in-plane and out-of-plane thermal conductivities of the composite film reach 24.96 and 2.46 W m−1 K−1, respectively. Compared with the pure cellulose nanofiber films, the thermal conductivity of composite films increased by 2819.2 and 187.6%, respectively. By designing two applications of composite films in the actual use process, the excellent heating conduction abilities in two directions have been proved. This measure to improve the thermal conductivities of composite films by MXene-copper binary fillers also provides ideas for the novel heat spreader.

Design and preparation of a novel colon-targeted tablet of hydrocortisone

ABSTRACT The objective of this research was to design a new colon-targeted drug delivery system based on chitosan. The properties of the films were studied to obtain useful information about the possible applications of composite films. The composite films were used in a bilayer system to investigate their feasibility as coating materials. Tensile strength, swelling degree, solubility, biodegradation degree, Fourier transform infrared spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), Scanning electron microscope (SEM) investigations showed that the composite film was formed when chitosan and gelatin were jointly reacted jointly. The results showed that a 6:4 blend ratio was the optimal chitosan/gelatin blend ratio. In vitro drug release results indicated that the Eudragit- and chitosan/gelatin-bilayer coating system prevented drug release in simulated intestinal fluid (SIF) and simulated gastric fluid (SGF). However, the drug release from a bilayer-coated tablet in SCF increased over time, and the drug was almost completely released after 24 h. Overall, colon-targeted drug delivery was achieved by using a chitosan/gelatin complex film and a multilayer coating system.

Fabrication of three-dimensional porous cobalt network-supported cobalt oxides nanoflake arrays for electrochemical energy storage

Smart combination of porous metal with metal oxides is important for the construction of high-performance electrochemical devices. Herein, we report three-dimensional Co network-supported Co3O4 nanoflake arrays by a facile electrodeposition and following hydrothermal process. 3D Co networks with porous branches and interconnected pores are well formed and used as the skeleton for the growth of porous Co3O4 nanoflake arrays. High porosity and integrated growth are combined in the composite electrode. As an anode material for lithium ion batteries, the Co network-supported Co3O4 nanoflake array electrode exhibits a high first discharge capacity (1164 mAh g−1 at 0.5 A g−1), good cycling stability (714 mAh g−1 after 100 cycles) and enhanced rate capability. The proposed method is useful for the construction of other porous metal/metal oxide composite films for application in electrochemical energy storage and catalysis.

Pyroelectric Properties of PVDF:MWCNT Nanocomposite Film for Uncooled Infrared Detectors and Medical Applications

The biocompatible and flexible polyvinylidene fluoride (PVDF) has a number of interesting pyroelectric and piezoelectric properties with fast, dynamic response for use in touch/tactile sensors, infrared detectors and thermal vidicon/imaging devices. Pyroelectric multi-walled carbon nano-tubes:polyvinylidene fluoride nano-composite films were fabricated via the solution casting technique. The dielectric, pyroelectric and piezoelectric characteristics of composite films were measured. Using foregoing parameters, figures-of-merit for infrared detectors, and thermal-vidicons were calculated. The results indicated figures-of-merit of the composite film that were higher than pristine polyvinylidene fluoride film. The potential applications of composite films in medical devices are also discussed.

Comparison of chitosan/starch composite film properties before and after cross-linking

Unmodified and cross-linked chitosan/starch composite films were prepared using the solvent evaporation method. The properties of the films were studied to obtain useful information about the possible applications of composite films. FT-IR, SEM, and swelling property investigations show that the cross-linking agent glutaraldehyde reacts in the chitosan and starch blend. The compatibility of chitosan and starch blends before and after cross-linking was studied by UV–vis spectroscopy. The compatibility of the blends deteriorated after cross-linking. This finding was confirmed by the results of mechanical properties. The films show improved water barrier performance after cross-linking. The use of trace concentrations of glutaraldehyde in chitosan/starch films allows for possible application in the biomedical field.

Magnetic nanocomposite thin films of BaFe 12O 19 and TiO 2 prepared by sol–gel method

The composite films with different weight ratio of barium ferrite to titanium dioxide are successfully prepared using sol–gel method for the first time. The morphology, crystal structure and magnetic properties of composite films are investigated with atomic force microscopy, X-ray diffraction and vibrating sample magnetometry. The results show that the composite films are uniform with no microcracks. The grain diameters are less than 100 nm. With the increase of barium ferrite, the grain diameter decreases. The composite films are composed of M-type hexagonal barium ferrite and rutile titanium dioxide. The composite films possess the excellent magnetic properties. The specific saturation magnetization and coercivity reach 18.3 emu/g and 3350 Oe, respectively. The application of composite films in magnetic recording and electromagnetic absorption fields is promising.