Hesham Moustafa

Using a PCL–L–Ag 2% NPs membrane for efficient removal of Cd ²⁺ , PO ₄ ³⁻ , and NO ₃ ⁻ at pH 6 in 90 min at 50 °C from wastewater.

1. Eichhornia crassipes (also known as the Nile Rose Plant in Egypt, NRP) is a prevalent, fast-growing, floating, and perennial plant that can thrive on the surface of freshwater in the warm climat...

Organic dyes, such as Eriochrome Black T (EBT) and methyl green (MG), are widely used in the textile industry, leading to their accumulation in the environment. Thus, the present study aimed to synthesise functional graphene oxide-grafted dapsone (GOgD), which was incorporated into a chitosan/gelatin (CGe) blend at different dosages (10%, 20%, and 30%) for the preparation of nanomembranes. A series of techniques and tests, including FT-IR spectroscopy, XRD, Raman spectroscopy, SEM, and mechanical and antibacterial property analyses, were applied for the characterization of functional GOgD and nanomembranes. Moreover, ultraviolet and visible light irradiations were used to evaluate the photocatalytic degradation of the EBT and MG dyes. The data revealed that optimum mechanical properties were found for CGe–GOgD 20%, with a value of ∼85 MPa, compared with the unfilled blend (61.35 MPa). However, the CGe–GOgD 30% nanomembrane exhibited the best photocatalytic activity for the degradation of EBT at pH 5.0 and that of MG at pH 8.0, with degradation efficiencies of 90.8% and 97.9% under visible light and 83% and 90% under UV light, respectively. The kinetics of degradation for both dyes showed pseudo-first-order kinetics. The mechanism involved the production of the highly oxidizing species ˙OH and ˙O₂ ⁻ upon light irradiation, which initiated the dye degradation process, generating CO₂ and H₂O as the reaction byproducts, with complete degradation until 120 min. The photocatalyst can be regenerated and reused three times, which decreases the cost of operation. The final impact on the antibacterial activities of the nanomembranes was also investigated, and the data revealed their strong antibacterial properties against E. coli and S. aureus with different inhibitory zone diameters ranging from 21 to 34 mm, as compared with the pristine matrix. In addition to the sustainable environmental benefits of the prepared CGe–GOgD 30% nanomembrane due to the degradation of harmful organic dyes, a strong antibacterial activity was observed, highlighting its wider environmental significance and promising applications in several ecological domains.

Nanocoating technology for by-product bagasse papers (BPs) utilizes hybrid polymers to create a superhydrophobic surface that enhances several properties of the BP material, which is highly promising for many applications, including active food packaging. Thus, this study aimed to prepare a functional nanocoating from polycaprolactone (PCL) grafted with dapsone (DAP) and silver nanoparticles (Ag NPs) for promoting the properties of hydrophilic BPs. The outcome of grafting DAP into PCL, as well as the interactions between the components after the coating process, were investigated by FT-IR and XRD analyses. Varied contents of the Ag NPs (i.e., 0.05%, 0.15%, and 0.30%) were used to fabricate a PCL-DAP–Ag nanocoating for treating the hydrophilic BPs using a dip-coating approach. The net-treated BPs (TBPs) were subjected to various analyses and tests, including morphological tests by XRD and SEM analyses, mechanical and barrier property evaluation, wettability assessment by the water contact angle (WCA), flammability resistance testing, and antibacterial activity measurements. The results revealed that most of the properties of the TBPs were further enhanced by the presence of Ag NPs, especially at 0.15%, compared to raw BP or unfilled TBP. The flammability resistance of TBP-0.30% Ag was achieved when the Ag NP content in the nanocoating reached 0.30%. Moreover, the treated BPs demonstrated superior antibacterial activity, which effectively killed microbes and inhibited their growth within an inhibitory zone ranging from 14 to 33 mm, depending on the microbe and sample type. In summary, PCL grafting is influential, and applying PCL-DAP-based Ag NPs as a nanocoating to hydrophilic BPs presents a highly promising strategy for antimicrobial food packaging applications.

Humidity surveillance is a requirement for several applications, including medical, pharmaceutical, food storage, and agriculture. This work describes the fabrication of humidity sensors from cellulose nanocrystals (CNCs) and ZnO nanoparticles (ZnO NPs) integrated inside a polyvinyl alcohol (PVA)/polyvinylpyrrolidone (PVP) blend created by a solvent‐casting method. A 10 wt.% of CNCs were used with variable quantities of ZnO NPs (i.e., 3, 7, and 15 wt.%) to prepare PVA/PVP nanocomposite films. The films were characterized using X‐ray diffraction, Raman spectroscopy, as well as mechanical, thermal, and antibacterial properties. In all cases, ZnO NPs improved morphology, thermal stability, and antibacterial properties. The tensile properties were slightly reduced compared to unfilled matrix (~33 MPa), but their tensile stress values were still higher than filled film‐based CNCs (P/CNC, 22.60 MPa). Whereas the outcomes from the antibacterial experiment illustrated that the halos of inhibition were observed for film‐based ZnO NPs with different diameters ranging from 3 to 16 nm, depending on the microbe and the film type. These results indicate that these films could be used in active packaging and the biological area because these materials prolong shelf life. Correspondingly, a P/CNC moisture sensor possessed higher sensitivity with low hysteresis over a wide range of relative humidity (11%–97%) and at 300 Hz.

More than 1.3 billion tons of foodstuffs are wasted each year because of their storage, handling, transportation or sale, resulting in the world suffering from famine and food shortages. This means that huge amounts of the resources utilized in food production are wasted. Greenhouse gas emissions caused by food degradation that gets wasted results in serious environmental and human health impacts. Food losses could be caused by microbes, temperature, humidity, UV-lights, or other factors related to the current pandemics, that have serious jeopardy impacts on the food security and the environment. Thus, smart packaging-based 2D-nanomaterials (2DMs) including sensors and pH-responsive tags have developed for achieving the quality and prolong the shelf-life of foodstuffs. Because they are capable to detect, sense, record internal or external changes in the product’s area. They also can give a prompt message or color changing to the producer or consumer to decide about the shelf lives and expiration dates for consuming the foodstuffs without deteriorating food and packaging. This study reviews the recent advancements in 2DMs regarding preparation, characterization, and applications including active/intelligent food packaging industries. Facile and green functionalization of 2DMs-based graphene oxide (GO) by folic acid or natural dyes enabling them be used in several sensor/artificial intelligence disciplines are discussed. Future insights on the challenges towards the potential outbreak prevention in foodstuffs and their control in long-term use and risk management of these materials are also discussed.