Effect of Kaolin clay and Ficus carica mediated silver nanoparticles on chitosan food packaging film for fresh apple slice preservation.

In this work, a novel antioxidant, antibacterial, and biodegradable food packaging film was elaborated, by incorporating natural kaolin clay (KC) and Ficus carica mediated silver nanoparticles (AgNPs) into Chitosan (Cht). A comparison of the physico-chemical and functional characteristics of the Cht/KC/AgNPs film was performed with those of Cht, Cht/KC, and Cht/AgNPs. SEM analysis showed a rough surface in the composite films containing KC particles because of their large diameter (50-120 µm) compared to AgNPs (20-80 nm). The FTIR analysis suggested that the interactions between Cht and AgNPs were stronger than those between Cht and KC. The tensile strength of Cht film increased from 16 MPa to ∼24 MPa in Cht/KC/AgNPs film. The introduction of KC and/or AgNPs considerably improved the light and moisture barrier capacity of the Cht film. The UV light transmittance decreased by 50 % for Cht film when incorporated by KC and AgNPs. Moreover, Cht/AgNPs was better in terms of antioxidant, antibacterial, and mechanical compared to Cht/KC, which was superior in biodegradability and water vapor barrier capacity. In particular, the Cht/KC/AgNPs film presented good barrier, antioxidants, antibacterial, mechanical, and biodegradable properties, owing to the synergistic effect between KC and AgNPs. For the packaging properties, all the films were tested for their ability to keep the freshness of apple slices as wrapping material. The films exhibited good results, and the Cht/KC/AgNPs showed promising performance regarding the moisture loss, browning index, total phenolic compound, and antioxidant activity of the apple slices. Moreover, the Cht/KC/AgNPs film exhibited a migration of silver meeting the standards set by EFSA and ECHA, which makes this film safe for food packaging.

Experimental and Theoretical Tests on the Corrosion Protection of Mild Steel in Hydrochloric Acid Environment by the Use of Pyrazole Derivative.

In this study, 1,5-diallyl-1H-pyrazolo [3,4-d] pyrimidin-4 (5H)-one (PPD) was evaluated as an anticorrosion agent for mild steel (MS) in 1 M HCl. The analysis was performed by weight loss (WL), potentiodynamic polarization measurement, and electrochemical impedance spectroscopy (EIS). The Tafel polarization showed that PPD is a mixed-type inhibitor and reaches 94% of the protective efficiency at 10-3 M. EIS results indicated that the resistance to charge transfer increases with increasing inhibitor concentration and the corrosion of MS is controlled by a charge transfer process. The inhibitor adsorption on the MS surface obeyed the Langmuir's adsorption isotherm. Thermodynamic parameters were calculated to elaborate the corrosion inhibition mechanism. The micrographic analysis revealed the existence of a barrier layer on the electrode surface with the presence of PPD. Theoretical examinations performed by electronic/atomic computer simulations confirmed that the obtained results were found to be consistent with experimental findings.

Food packaging composite film based on chitosan, natural kaolinite clay, and Ficus. carica leaves extract for fresh-cut apple slices preservation.

The problem of environmental plastic contamination is one of the most serious issues facing our world today. The majority of the packaging materials used to preserve food are made of plastic which is considered an environmental issue. Natural kaolinite clay (KC) and Ficus leaf extract (FLE) were combined with chitosan in this work to create a novel antioxidant and biodegradable food packaging film. Chitosan/KC/FLE film was compared to chitosan film, Chitosan/KC, and Chitosan/FLE films in terms of structural, physical, and functional aspects. The addition of FLE and/or KC significantly improved the light and moisture barrier characteristics, mechanical properties, and antioxidant capabilities of chitosan film. Moreover, KC addition had a remarkable impact on the water vapor permeability and the biodegradability of the chitosan film. Because of the synergistic action of FLE and KC, the Chitosan/KC/FLE film delivered strong barrier and antioxidant capabilities. Furthermore, Chitosan/KC/FLE film was tested as packaging material on fresh-cut apple slices and demonstrated good food preservation regarding the weight loss, browning index, and total phenolic content of the fruit. According to our findings, Chitosan/KC/FLE film might be employed as a possible food packaging material in the food industry.

Chitosan-kaolinite clay composite as durable coating material for slow release NPK fertilizer.

Durable chitosan-based coating material used as a barrier for slow-release fertilizers in the agricultural soil. This approach decreases the intense usage of fertilizer and works on their accessibility for the plants' necessities. In present paper, the proposed coating material was prepared on the basis of chitosan-kaolinite composite (CS-Gl-K). Fourier transform infrared spectroscopy analysis (FTIR), Scanning Electron Microscopy (SEM), thermogravimetric analysis (ATG), XRD, swelling degree and biodegradability studies were used to analyze the influence of the kaolinite clay incorporation in chitosan film properties. The characterization of the chitosan composites has been thoroughly studied. The NPK mineral fertilizer was coated according to the dip-immersing process of chitosan-kaolinite composites. Slow-release efficiency was evaluated by determining the rate of phosphorus release from the covered granules into water and soil. Moreover, phosphorus release from coated NPK/CS-Gl-K granules was generally delayed contrasted with NPK/uncoated. In addition, the biodegradation investigation of the composite material (CS-Gl-K) in soil was affirmed its durability. The proposed coating material has good slow-release properties, low cost and is environmentally friendly. The FTIR, ATG and XRD spectra revealed a good intercalation between the kaolinite-clay pores and chitosan chains.

Anticorrosion effect of a green sustainable inhibitor on mild steel in hydrochloric acid.

Green inhibitors are an important way to decrease the corrosion rate of different industrial metals. The present work shows the corrosion behavior of the mild steel medium (MS) in hydrochloric acid 1 M by the aqueous extract of Artemisia Herba Alba (AHA), which is an green sustainable inhibitor to reduce its corrosive action by exploiting a variety of techniques and methods namely: Weight loss, electrochemical techniques [electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP], SEM-EDX, XPS and theoretical calculations for the majority molecule. Hydrodistillation is the extraction method that has been used to prepare the aqueous extracts. Otherwise, phytochemical screening characterization of different parts of the plant was applied to show the proportions of chemical compounds that exist in the plants. The highest inhibition efficiency obtained is 92% for 0.4 g/L of AHA aqueous extract in 1 M HCl at 303 K. PDP study confirmed that the AHA extract is of mixed-kind inhibitor. A CPE, Q determined by fit and graphical methods plotted by synthetic data, was utilized. To characterize the mild steel surface, scanning electron microscopy was also used; SEM/EDX allowed the investigation of the AHA effect on the surface of mild steel specimens. To comprehend the adsorption mechanism of AHA extract for MS in the 1 M HCl, XPS technique was accomplished. Theoretical approaches based on chemical quantum calculations and molecular dynamics simulation clearly explains the mode of adsorption of the majority molecule on the iron surface.

Coupling of chemical, electrochemical and theoretical approach to study the corrosion inhibition of mild steel by new quinoxaline compounds in 1 M HCl.

The corrosion inhibition displays of two quinoxaline derivatives, on the corrosion of M-steel (M-steel) in 1 M HCl was studied by gravimetric, electrochemical, scanning electron microscopy (SEM), functional density theory (DFT) and molecular dynamic simulation (MD). The inhibitory efficacy increases with decreasing temperature and increases with inhibitor concentration and reached to 96 % (NSQN) and 92 % (CSQN) at 303 K and the optimum concentration (1×10-3 M). Ultraviolet-visible (UV-vis) spectroscopic analyses confirmed the presence of chemical interactions between the inhibitors and MS surface. The adsorption of NSQN & CSQN on the metallic surface obeys the Langmuir isotherm. A potentiodynamic polarization study confirmed that the inhibitors are of mixed-kind inhibitors. Theoretical computation (DFT) and molecular dynamics simulation (MD) are utilized to understand the mechanism of inhibition.