Gamma irradiation effects on polycaprolactone/zinc oxide nanocomposite films

Preparation and application of irradiated polyvinyl alcohol/starch/pumice composites for adsorption of basic dye: Isotherm and kinetics study

Even at low concentrations, organic dye pollution entering water resources from the textile, paper, and pharmaceutical industry sectors poses a serious hazard to human and aquatic life. One of the most significant remediation methods is the adsorption method. In the present study, the uptake of basic violet 7 (BV7) synthetic dye was investigated utilizing Poly (vinyl alcohol)/starch/Pumice [poly (PVA/St/Pu)] composite films prepared by a simple casting of both PVA and St with Pu and then irradiated by electron beam (EB) source to prompt curing. Numerous characterization methods, such as SEM, FTIR, X-ray diffraction (XRD, and other measurements, were examined on the prepared sample. The tensile strength (TS) of all composites was increased by increasing the radiation dose up to 10 kGy. TS was increased by 3 php of Pu, and an overload of Pu led to a decrease in TS values. The elongation at break (Eb) of the prepared composite increased at 3 Pu, then decreased as the quantity of the pumice increased, while the Eb was decreased by irradiation. The effects of the produced polymeric films' composition and irradiation dose on the basic violet 7 (BV 7) dye adsorption were studied. It was found that the adsorption capacity of poly (PVA/St/9 php Pu-10 kGy) toward the BV 7 dye was 64.9 mg/g at the optimal conditions: pH = 11, contact time = 480 min., adsorbent dosage = 0.2 g., concentration = 150 mg/l, and temperature = 298 K. The adsorption process fitted with the pseudo-second-order model, Freundlich adsorption isotherms were found to be spontaneous and endothermic.

Gamma radiation effect on the chemical, mechanical and thermal properties of PCL/MCM-48-PVA nanocomposite films

In this work, poly (vinyl alcohol) (PVA) was employed to produce a Mesoporous Composition of Matter-48 Modified (MCM-48-M or MCM-48-PVA). After surface modification, MCM-48-M was used to produce nanocomposite (NC) films with polycaprolactone (PCL) as a matrix at room temperature. PCL and MCM-48 nanoparticles (NPs) were chosen due to their great biocompatibility and low toxicity. However, MCM-48-M is more compatible with PCL than MCM-48. NC films were sterilized by gamma radiation with a dose of 25 kGy and characterized by experimental techniques to investigate their chemical, mechanical (tensile) and thermal properties. Scanning electron microscopy (SEM) and transmission electronic microscopy (TEM) results indicated that MCM-48-M exhibited a random distribution in the PCL matrix. The PCL chemical structure was preserved in NC films as described by Fourier transform infrared (FT-IR) spectroscopy as well as the tensile and thermal properties of NC films. FT-IR and thermogravimetric analysis (TGA) results showed surface modification. X-ray diffraction (XRD) and differential scanning calorimetry (DSC) showed that crystalline symmetries were preserved and the crystallinity of NC films had small variations in all samples before and after irradiation, respectively. But, our results did not indicate major changes showing that this method is successful for the sterilization of PCL/MCM-48-PVA NC films.

Effect of high γ-irradiation dosage on physico-chemical, functional and emulsion properties of almond gum powder

Almond gum is a natural biopolymer produced by Almond tree that is non-toxic, biodegradable, and biocompatible. These features make it suitable for applications in the food, cosmetic, biomedical, and packaging industries. To ensure its wide application in these fields, green modification process is necessary. Gamma irradiation is often used as a sterilisation and modification technique, due to its high penetration power. Thus, evaluating its effects on the physicochemical and functional properties of gum after exposure is important. To date, limited studies have reported the use of high dose of γ-irradiation on the biopolymer. Therefore, the present study demonstrated the effect of a high dose of γ-irradiation (0, 24, 48, and 72 kGy) on the functional and phytochemical properties of almond gum powder. The irradiated powder was studied for its color, packing, functional, and bioactive properties. The results revealed a significant increase in water absorption capacity, oil absorption capacity, and solubility index. However, a decreasing trend was observed in the foaming index, L value, pH, and emulsion stability with the radiation dose. Besides, sizable effects were observed in the IR spectra of irradiated gum. Phytochemical properties were significantly improved with an increase in dose. The emulsion was prepared from irradiated gum powder, where the highest creaming index was observed at 72 kGy and a decreasing trend in zeta potential. These results suggested that γ-irradiation treatment is a successful method to generate desirable cavity, pore sizes, functional properties, and bioactive compounds. This emerging approach could modify the natural additive with distinct internal structure for specific uses in wide range of food, pharmaceutical and other industrial applications.

Designing Nanofibrous Poly(ε-caprolactone)/Hydroxypropyl Cellulose/Zinc Oxide/Melilotus Officinalis Wound Dressings Using Response Surface Methodology

Nanofibrous wound dressing is one of the most prominent stratagems for wound caring/management. This research is an approach for designing an electrospun wound dressing based on poly(ε-caprolactone)/hydroxypropyl cellulose/zinc oxide nanoparticles (PCL/HPC/n-ZnO), in which response surface methodology (RSM) was utilized to ascertain the optimum sample. It was observed that the addition of n-ZnO and Melilotus Officinalis (MO) extract could increase the fibers mean diameter, pore size, and crystallinity of mats. The mentioned quantities for a sample with the highest MO content (PHZM10) were equal to 469±105 nm, 544±370 nm, and 49.67%, respectively. Moreover, enhancing the amount of MO led to an increase in mechanical properties. In this respect, the PHZM10 sample had the modulus, strength, and toughness of 82.41±0.61, 20.45±0.30 MPa, and 4194.86 mJ, respectively. Also, according to the MTT assay, no cytotoxicity was reported from any of the manufactured samples. Besides, it was concluded that the antibacterial activity and nanofibrous structure of mats, and also their potential for release of MO extract could accelerate the wound healing. Hence, the wound closure index for the PHZM10 group was 99.3±1.1%. Based on all noted results, the PCL/HPC/n-ZnO/MO electrospun mats can be proposed as reassuring wound dressing candidates.

Evaluation of Biomechanical and Chemical Properties of Gamma-Irradiated Polycaprolactone Microfilaments for Musculoskeletal Tissue Engineering Applications

An appropriate and reliable sterilization technique is crucial for tissue engineering scaffolds. Skeletal muscle scaffolds are often fabricated using microfilaments of a wide variety of polymers. One method for sterilization is 25 kGy of gamma irradiation. In addition, sterilization through irradiation should administer a dose within a specific range. Radiation directly affects the chemical and mechanical properties of scaffolds. The accuracy and effects of irradiation are often not considered during sterilization procedures; however, these are important since they provide insight on whether the sterilization procedure is reliable and reproducible. This study focused on the chemical and mechanical characterization of 25 kGy gamma-irradiated scaffold. The accuracy and uncertainty of the irradiation procedure were also obtained. X-ray diffraction (XRD) and differential scanning calorimetry (DSC) analyses were performed to determine whether the crystallinity of the polymer changed after irradiation and whether gamma rays influenced its thermal properties. The tensile parameters of the microfilaments were analyzed by comparing irradiated and nonirradiated scaffolds to determine whether gamma radiation changed their elastic behavior. Dose distribution and uncertainty were recorded with several dosimeters. The results showed that the irradiation process slightly affected the mechanical parameters of the scaffold; however, it did not modify its crystallinity or thermal properties. The irradiation was uniform, since the measured uncertainty was low. The scaffold was pathogen-free after 7 days; this meant sterilization was achieved. These results indicated that gamma-sterilized scaffolds were a promising material for use as a skeletal muscle analog material for tissue-engineering applications because they can be sterilized with gamma rays without changing their chemical structure and mechanical properties. This study provided the dose distribution measurement and uncertainty calculations for the sterilization procedure.

Gamma irradiation influence on mechanical, thermal and conductivity properties of hybrid carbon nanotubes/montmorillonite nanocomposites

A thermoplastic elastomer (TPE) based nanocomposite with the same weight ratio of hybrid nanofillers composed of carbon nanotubes (CNTs) and montmorillonite nanoclay (DK4) was prepared using a melt blending technique with an internal mixer. The TPE composite was blended from polylactic acid (PLA), liquid natural rubber (LNR) as a compatibilizer and natural rubber (NR) in a volume ratio of 70:10:20, respectively. The weight ratio of CNTs and DK4 was 2.5 wt%. The prepared samples were exposed to gamma radiation at range of 0–250 kGy. After exposure to gamma radiation, the mechanical, thermo-mechanical, thermal and electrical conductivity properties of the composites were significantly higher than unirradiated TPE composites as the irradiation doses increased up to 150 kGy. Transmission electron microscopy (TEM) micrographs revealed the good distribution and interaction between the nano-fillers and the matrix in the prepared TPE hybrid nanocomposites. In summary, the findings from this work definite that gamma irradiation might be a viable treatment to improve the properties of TPE nanocomposite for electronic packaging applications.

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Carbon nanotubes/montmorillonite nanocomposite was prepared via a melt blending.

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Gamma irradiation improved the interaction and dispersion of nanofillers in matrix.

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At 150 kGy, the thermo-mechanical properties and conductivities improved.