Wafaa Abou-Elseoud

Developing cost-effective, bio-based adsorbents for hazardous battery industry effluents is a major environmental challenge. This study isolated cellulose nanofibers (CNFs) from primary paper sludge (PS)—a tissue manufacturing waste—via chemical modification using (2,2,6,6-Tetramethylpiperidin-1-yl)oxyl oxidation (TEMPO oxidation) and ultrasonication to fabricate highly porous aerogels. The PS-CNF aerogels were evaluated for removing battery-related metal ions (Pb²⁺, Cd²⁺, Co²⁺, Mn²⁺, Ni²⁺, and Li⁺). To assess the structural impact of residual kaolin in the sludge, performance was compared against aerogels derived from fiber dust (FD) waste, as well as a commercial resin (Purolite C-100). The PS-CNF aerogels demonstrated superior maximum adsorption capacities of 39.28 mg/g for Pb²⁺, 29.80 mg/g for Cd²⁺, 21.05 mg/g for Co²⁺, 20.19 mg/g for Mn²⁺, 16.80 mg/g for Ni²⁺, and 11.33 mg/g for Li⁺. They consistently outperformed the FD-CNF matrix across the entire series. This enhanced efficiency is attributed to the residual kaolin in the paper sludge, which also acts as a physical spacer, increasing the aerogel’s internal porosity. Adsorption generally followed the Langmuir isotherm and pseudo-second-order kinetics. Furthermore, the PS-CNF aerogels exhibited higher efficiency than the commercial Purolite C-100 cation exchange resin. Ultimately, this work demonstrates the potential of upcycling paper sludge into sustainable, high-performance adsorbents for treating toxic battery effluents.

Antimicrobial and UV-resistant coatings are important finishing materials for making specialty wood products. In the current work, anti-bacterial and UV-resistant coatings were prepared from nitrocellulose (NC) and pomegranate peel extract (PGE). Different ratios of PGE were added to NC solution (up to 10 wt.% of NC) and the effect of PGE on the viscosity of NC solution, optical, UV-absorption, mechanical, moisture sorption, and antibacterial properties of NC films was studied. Finally, the NC/PGE solution with the appropriate antibacterial activity was sprayed onto the surface of beechwood and its surface was evaluated and compared to neat NC coating regarding gloss, color, change in color due to daylight and thermal aging, and wettability by water. The results showed that PGE reduced the viscosity of NC solution even at low concentrations. All the NC/PGE films had good homogeneity, transparency, UV light absorption, film flexibility, and good antibacterial properties against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli bacteria at PGE content 6% or higher. PGE moderately increased the moisture sorption of NC films at high relative humidity (98%). Beechwood was sprayed with NC/8% PGE solution in ethyl acetate; the presence of PGE in NC didn’t affect the visual appearance or light indices (L, a, and b) of the coated wood when compared to the coating with neat NC. The NC/8%PGE coating had high stability against daylight aging while there was no difference in color change between the wood coated with NC and NC/8%PGE after thermal aging. The study showed the potential of PGE as a renewable and safe anti-bacterial and UV-resistant additive for nitrocellulose lacquers used in furniture. Graphical abstract

Bio-based polymer composites find increasing research and industrial interest in different areas of our life. In this study, cellulose nanofibers (CNFs) isolated from sugar beet pulp and nanoemulsion prepared from sugar beet pectin and pomegranate extract (PGE) were used for making films and used as coating with antioxidant and antimicrobial activities for paper. For Pectin/PGE nanoemulsion preparation, different ratios of PGE were mixed with pectin using ultrasonic treatment; the antibacterial properties were evaluated to choose the formula with the adequate antibacterial activity. The antioxidant activity of the nanoemulsion with the highest antimicrobial activity was also evaluated. The nanoemulsion with the optimum antibacterial activity was mixed with different ratios of CNFs. Mechanical, greaseproof, antioxidant activity, and antibacterial properties of the CNFs/Pectin/PGE films were evaluated. Finally, the CNFs/Pectin/PGE formulation with the highest antibacterial activity was tested as a coating material for paper. Mechanical, greaseproof, and air porosity properties, as well as water vapor permeability and migration of the coated layer from paper sheets in different media were evaluated. The results showed promising applicability of the CNFs/Pectin/PGE as films and coating material with antibacterial and antioxidant activities, as well as good stability for packaging aqueous, fatty, and acidic food products.

Rice straw nanofibers (RSNF) with high lignin content were used in making nanocomposites with graphene oxide (GO) at loading ratios from 0.625% to 5% (based on weight of RSNF). The prepared RSNF/GO films were characterized regarding their tensile strength, equilibrium moisture content (EMC), and electrical properties. Microstructure of the films was examined using scanning electron microscopy (SEM). Addition of 2.5% of GO resulted in increasing tensile strength and Young's modulus by 33.5% and 21.5%, respectively. Presence of GO significantly reduced moisture sorption of the films. Electrical conductivity measurement showed significant increase in permittivity ( ε ′) upon increasing GO loading. The ionic conductivity value of films containing 5% of GO was 10 ⁻⁷ S cm ⁻¹ , which is acceptable value for use as antistatic and/or dissipated films. The electrical properties of the prepared low‐cost high‐lignin‐content RSNF/GO films could have potential use in flexible electronic applications such as in energy harvesting and storage.

In this study, the effect of pectin extraction method on the properties of cellulose nanofibers (CNFs) isolated from sugar beet pulp (SBP) was studied. Pectin was extracted by the industrially practiced method by sulfuric acid hydrolysis or by enzymatic hydrolysis using a cellulase/xylanase enzymes mixture. The CNFs were then isolated by high-pressure homogenization and investigated in terms of their chemical composition, crystallinity, size, degree of polymerization, and re-dispersion in water after freeze-drying. The mechanical properties and surface characteristics of CNF films were also studied. The results showed that fibrillation of the de-pectinated SBP was more efficient for the acid hydrolyzed SBP. CNFs from the acid-hydrolyzed SBP had a slightly wider diameter, higher crystallinity, viscosity, and α-cellulose content but a lower degree of polymerization than CNFs from the enzyme-hydrolyzed SBP. Owing to the presence of more residual hemicelluloses in the CNFs from the enzyme-hydrolyzed SBP, the CNFs had higher re-dispersion ability in water. CNF films from enzyme-hydrolyzed SBP displayed slightly better mechanical properties and higher water contact angle than acid-hydrolyzed CNF films. Graphic abstract