Biophysical studies of modified PVC sheet based on sunflower oil for antistatic and blood bags applications.

In this work, the surface of polyvinyl chloride PVC sheet was modified by blending it with sunflower seed oil SSO to obtain PVC sheet/SSO films of ratios 100/0, 90/10, 80/20, 70/30, 60/40, and 50/50 (v/v)% using the solution casting method. Various techniques were used to characterize the prepared films, besides the use of hemolysis assays and blood clot formation tests. FTIR spectra revealed that there was a good interaction between the PVC sheet and the oil. The dielectric measurement indicated that SSO addition enhanced the dielectric properties of the sheet. The study of dielectric relaxation times confirmed the interaction between SSO and the sheet. DC conductivity increased to 6 × 10-6 S/m, so it could be applied in antistatic applications. Also, SSO addition increased the value of the thermal stability. According to SEM micrographs, the film was roughened at a ratio of 60/40 and smoothed out at 50/50. This behavior was confirmed with roughness and contact angle measurement results, in which the film of ratio 60/40 had the highest value equal to (72.03°) and then decreased at 50/50 to (59.62°). These results were confirmed by XRD measurement as the crystallinity increased at the film ratio of 60/40 and decreased again at 50/50. Also, the ratio of 60/40 demonstrated a large decrease in thrombus weights along with a slight increase in hemolysis, which is within the acceptable range and has a high degree of biocompatibility, so this concentration is recommended to be used in blood bags applications.

Fabrication of green anti-microbial and anti-static cement building bricks.

The design cement mix of grade 350 was created in accordance with Egyptian Standards by partially substituting the fine aggregate with WPVC waste in various weight percentages (10, 20, 30, 40, 50, 75, and 100%). A control mix with 0% replacement was also prepared. The W/C ratio was about 0.5 for all mixes. Compressive, flexure strength, bulk density, and absorption tests were studied. For WPVC replacement, until 30%, compressive strength and flexure strength are acceptable with respect to standerds. Thermal treatment at 200 °C improves the compressive strength, flexure strength and water absorption for 20% WPVC only. The dielectric properties of all cement paste mixes before and after heat treatment, over a frequency range (0.1-106 Hz), were measured as a function of frequency. For dielectric properties and conductivity, an improvement was obtained until 30% WPVC. After this percentage, the dielectric properties and the conductivity got worse. So, cement paste with 30% WPVC as replacement of sand is the optimum ratio with conductivity in range of 10-12 S/cm, which is a good choice for antistatic cement paste applications (10-10-10-12 S/cm). The antimicrobial efficacy of the prepared cement samples of WPVC concentrations (0, 20 and 30) % were studied, the number of grown microbial colonies decreased for all the samples compared to control tap water and decreased by introducing WPVC into the cement paste sample. So, it is recommended to use these samples in places that should be carefully shielded from bacterial infections and static electric charge dangers.

Effect of apricot kernel seed extract on biophysical properties of chitosan film for packaging applications.

Chitosan is a natural biodegradable biopolymer that has drawbacks in mechanical and antibacterial properties, limiting its usage in biological and medicinal fields. Chitosan is combined with other naturally occurring substances possessing biological antibacterial qualities in order to broaden its application. Ethanolic apricot kernel seed extract was prepared, analyzed, and incorporated into chitosan film with different concentrations (0.25, 0.5, and 0.75 wt%). Furthermore, the effect of AKSE and γ-radiation (20 Gy and 20 kGy) on the physical properties of the film was studied. The prepared films were characterized by Fourier transform infrared spectroscopy (FTIR), which revealed that AKSE did not cause any change in the molecular structure, whereas the γ-irradiation dose caused a decrease in the peak intensity of all concentrations except 0.75 wt%, which was the most resistant. In addition, their dielectric, optical, and antimicrobial properties were studied. Also, AKSE-enhanced optical qualities, allowed them to fully block light transmission at wavelengths of 450-600 nm. The dielectric properties, i.e., permittivity (ε'), dielectric loss (ε''), and electrical conductivity (σ), increased with increasing AKSE concentration and film irradiation. The antimicrobial studies revealed that the antimicrobial activity against Escherichia coli and Canodida albicans increased with AKSE incorporation.