Influence of nanostructured TiO2 additives on some physical characteristics of carboxymethyl cellulose (CMC)

Deep insight into physical properties of carboxymethyl cellulose-barium oxide nanocomposites

Nanocomposites, blending the unique properties of inorganic nanoparticles with polymers, are gaining momentum in various industries. This study delves into the synthesis and characterization of barium oxide (BaO)-doped carboxymethyl cellulose (CMC) nanocomposites, focusing on their structural, optical, electrical, and dielectric properties. Using an in-situ polymerization method, CMC films were doped with 5 % and 10 % BaO nanoparticles. X-ray diffraction analysis revealed that the doped samples exhibited enhanced crystallinity compared to pure CMC, with crystallinity percentages measured at 37.95 % and 28.86 % for 5 % and 10 % BaO, respectively, indicating the successful incorporation of BaO. Scanning electron microscopy illustrated the distribution of BaO nanoparticles, showing spherical agglomerations on the film surface. SEM analysis reveals emergence of spherical agglomerations and bright spots on nanocomposite film surface upon BaO introduction, indicating BaO nanoparticles presence. Further, the BaO nanoparticles act as catalytic and nucleating agents, influencing crystalline structure nucleation and growth, potentially enhancing film homogeneity and structural integrity. In addition, UV-visible spectroscopy elucidated the optical properties, indicating a shift in the bandgap from indirect to direct with BaO addition. The bandgap values decrease upon the addition of BaO, indicating a transition from an amorphous to a nanocrystalline structure, with respective reduction percentages of 22.73 % and 10.71 % for the 5%BaO/CMC and 10 %BaO/CMC samples compared to CMC. Electrical conductivity measurements showed enhanced conductivity in 10 % BaO/CMC due to improved charge carrier mobility, supported by dielectric studies demonstrating increased dielectric. The introduction of 5 % and 10 % BaO resulted in reductions of approximately 62.06 % and 65.77 %, respectively, compared to the pure CMC sample. This decrease in dielectric loss indicates an enhancement in the electrical properties of the nanocomposites. This comprehensive investigation could give further insights into the different properties of BaO-doped CMC nanocomposites, offering insights into their potential applications in various fields such as electronics, energy storage, and optoelectronics.

Hydrophobic carboxymethyl cellulose as a clean-up sorbent in the determination of nitrofuran metabolites in animal-fat samples

Hydrophobic carboxymethyl cellulose (CMC) biopolymers were fabricated for the removal of fat from food sample matrices. The hydrophobic CMCs were synthesised via the esterification of CMC with three alcohols with carbon chains of different lengths, methanol, butanol, and octadecanol, in the presence of sulfuric acid. The structure of the three synthesised hydrophobic CMCs was verified using FT-IR, and the physicochemical properties were investigated by TGA, SEM, and X-ray. Characterization confirmed the successful synthesis of the hydrophobic CMCs and that the hydrophobic groups are embedded in the sorbent biopolymer to interact with fat and reduce the fat content of the sample extract. Moreover, the performance of the fabricated hydrophobic CMCs was studied in two applications: fat removal and the determination of nitrofuran (NF) metabolites in fat samples. In the first application, excellent results were observed for fat removal; the highest percentage of fat removed from food sample extracts was 94.2% and the lowest was 88.5%. Successful results were also observed in the determination of NF metabolites in fat samples, as the final extract was clear and pure using the hydrophobic CMCs, while it was turbid for the control sample. In addition, the recovery of four NF metabolites was in the range of 97-117%. In general, the hydrophobic CMCs showed promising and satisfactory results, with CMC-C18 exhibiting the best results. The NF detection method was validated using CMC-C18 in three spiking levels; 0.5, 1.0 and 1.5 μg kg-1. The average recoveries of NF range between 83.3 to 104.3%, and the intra-day precision was determined by coefficient of variation, which was below 10% for all NF. The limit of detection and limit of quantification were between 0.6 to 0.9 and 0.20 to 0.28 μg kg-1 respectively. For linearity, the correlation coefficient (r2) was higher than 0.99 for NF metabolites. Overall, the hydrophobic CMCs can be further developed and safely used as green sorbents in food analysis applications.

Advanced Fabrication and Multi-Properties of Aluminum-Based Aerogels from Aluminum Waste for Thermal Insulation and Oil Absorption Applications

Metal-based aerogels have attracted numerous studies due to their unique physical, structural, thermal, and chemical properties. Utilizing aluminum waste, a novel, facile, environmentally friendly approach to aluminum-based aerogels is proposed. In this work, the aluminum-based aerogels produced do not use toxic chemicals unlike conventional aerogel production. Aluminum powder, with poly(acrylic acid) and carboxymethyl cellulose as binders, is converted into aluminum-based aerogels using the freeze-drying method. The aluminum-based aerogels have low density (0.08–0.12 g/cm3) and high porosity (93.83–95.68%). The thermal conductivity of the aerogels obtained is very low (0.038–0.045 W/m·K), comparable to other types of aerogels and commercial heat insulation materials. Additionally, the aerogels can withstand temperatures up to 1000 °C with less than 40% decomposition. The aerogels exhibited promising oil absorption properties with their absorption capacity of 9.8 g/g and 0.784 g/cm3. The Young’s modulus of the aerogels ranged from 70.6 kPa to 330.2 kPa. This study suggests that aluminum-based aerogels have potential in thermal insulation and oil absorption applications.

Carboxymethyl Cellulose/Copper Oxide-Titanium Oxide Based Nanocatalyst Beads for the Reduction of Organic and Inorganic Pollutants

In this work, we have developed novel beads based on carboxymethyl cellulose (CMC) encapsulated copper oxide-titanium oxide (CuO-TiO2) nanocomposite (CMC/CuO-TiO2) via Al+3 cross-linking agent. The developed CMC/CuO-TiO2 beads were applied as a promising catalyst for the catalytic reduction of organic and inorganic contaminants; nitrophenols (NP), methyl orange (MO), eosin yellow (EY) and potassium hexacyanoferrate (K3[Fe(CN)6]) in the presence of reducing agent (NaBH4). CMC/CuO-TiO2 nanocatalyst beads exhibited excellent catalytic activity in the reduction of all selected pollutants (4-NP, 2-NP, 2,6-DNP, MO, EY and K3[Fe(CN)6]). Further, the catalytic activity of beads was optimized toward 4-nitrophenol with varying its concentrations and testing different concentrations of NaBH4. Beads stability, reusability, and loss in catalytic activity were investigated using the recyclability method, in which the CMC/CuO-TiO2 nanocomposite beads were tested several times for the reduction of 4-NP. As a result, the designed CMC/CuO-TiO2 nanocomposite beads are strong, stable, and their catalytic activity has been proven.

Surface Characterization and Electrical Properties of Low Energy Irradiated PANI/PbS Polymeric Nanocomposite Materials

In this work, nanocomposite samples of polyaniline (PANI) and lead sulfide nanoparticles (PbSNPs) were prepared, utilizing the solution preparation method, for implantation in energy storage elements. The PANI/PbS films were irradiated by different fluences of oxygen beam: 5 × 1016, 10 × 1016, and 15 × 1016 ions.cm−2. The composite was investigated by XRD, SEM, DSC, and FTIR. After ion irradiation, the Tg and Tm values decreased by 4.8 °C and 10.1 °C, respectively. The conductivities, electrical impedances, and electrical moduli of untreated and irradiated samples were examined in frequencies ranging from 102 Hz to 5 MHz. Moreover, the ion beam caused a modification in the dielectric characteristics of PANI/PbS. The dielectric constant ε′ was improved from 31 to 611, and the electrical conductivity increased from 1.45 × 10−3 S/cm to 25.9 × 10−3 S/cm by enhancing the fluence to 15 × 1016 ions.cm−2. Additionally, the potential energy barrier, Wm, decreased from 0.43 eV to 0.23 eV. The induced changes in the dielectric properties and structural characteristics of the PANI/PbS samples were determined. These modifications provide an opportunity to use irradiated PANI/PbS samples for several applications, including microelectronics, batteries, and storage of electrical energy.

Fabrication of cerium titanate cellulose fiber nanocomposite materials for the removal of methyl orange and methylene blue from polluted water by photocatalytic degradation

In this study, cellulose fibers (Cf), extracted from sunflower seed husk, and different molar ratios of cerium titanate (Ce-Ti) NPs were prepared from sunflower seed husk extract by a green biosynthesis approach. Cf and Ce-Ti NPs were reacted via cross-linking reaction to synthesize a novel nanocomposite photocatalyst of Ce-Ti/Cf. Using Fourier-transform infrared (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM-EDX) spectroscopy, all manufactured materials were characterized. The results obtained from FTIR and EDX analyses indicated that Cf and its nanocomposites (0.1 Ce-Ti/Cf, 0.3 Ce-Ti/Cf, and 0.5 Ce-Ti/Cf) were successfully prepared by harnessing biomass extract from sunflower seed husk. Furthermore, XRD revealed that the degree of crystallinity of the nanocomposites was enhanced by increasing the molar ratios of the Ce-Ti NPs. The photocatalytic activity of as-fabricated 0.1 Ce-Ti/Cf, 0.3 Ce-Ti/Cf, and 0.5 Ce-Ti/Cf nanocomposite samples was investigated on methylene blue (MB) and methyl orange (MO) dyes as model organic compounds found in wastewaters. The effects of dose, contact time, and pH on the photocatalytic activity of the synthesized nanocomposites, the photodegradation kinetic parameters of MB, and MO degradation with/without the addition of H2O2 were also studied. The results revealed that high photodegradation efficiency could be obtained as the ratio of TiO2 in the Ce-Ti nanocomposite formula increases. Moreover, after sunlight irradiation, the adsorption capacity and the dye decomposition ratio significantly increase during the early contact time and reach equilibrium at about 240 and 120 min for 0.5 Ce-Ti/Cf nanocomposite photocatalyst in the absence and presence of hydrogen peroxide, respectively. In light of the obtained results and the practical wastewater treatment study conducted, the prepared photocatalyst from Ce-Ti/Cf nanocomposites could be a promising material for treating dye wastewater especially collected from Egypt.

Carboxymethyl Cellulose (CMC) Based Electrospun Composite Nanofiber Mats for Food Packaging

Cellulose is one of the most abundantly available natural polymers. Carboxymethyl cellulose (CMC) belongs to the cellulose family and has different degrees of substitution. Current research comprises the fabrication and characterization of CMC nanofibers using polyvinyl alcohol (PVA) and polyvinylpyrrolidone (PVP) as capping agents and carriers for sustainable food packaging applications. Recently authors successfully fabricated smooth and uniform nanofibers of stated polymers and optimized the ratios of three polymers for continuous production. However, in this research, it was further characterized for mechanical properties, surface properties, structural properties, air permeability, and chemical properties to confirm the suitability and scope of tri-component nanofibrous mats in food packaging applications. Different fruits and vegetables were packed in a plastic container and closed by nanofiber mats and by a plastic lid. All samples were observed after a specific period of time (fruits were kept for 40 days while vegetables were kept for 10 days in the controlled environment). It was observed in the results that fruits and vegetables closed by nanofiber based webs exhibited better freshness and lower accumulation of moisture as compared to that of containers with plastic lids. From the results of performed tests, it was observed that nanofiber mats possess enough mechanical, structural, and morphological properties to be used as food packaging.

TEMPO oxidized nano-cellulose containing thermo-responsive injectable hydrogel for post-surgical peritoneal tissue adhesion prevention

The objective of this study was to present an effective injectable adhesion barrier comprised of TEMPO-oxidized cellulose nanofiber (TOCN), methyl cellulose, carboxymethyl cellulose, and polyethylene glycol. Hydrogels with different concentrations (0.2, 0.5, 0.8, 1% w/v) of bio compatible TOCN were investigated to determine their abilities to prevent post-surgical peritoneal adhesion using a rat cecal wall abrasion model. Sol-gel transition at body temperature (37 °C) was optimized by adjusting concentration of sodium ions (Na⁺), with a gelation time of 45 ± 7 s. These TOCN containing hydrogels showed non cytotoxicity to rat bone marrow mesenchymal stem cells (RBMSCs) and L929 fibroblast cells as cell models during in vitro assessment. Degradation studies revealed that, TOCN concentration in hydrogel was inversely proportional to hydrolytic degradation rate. From in vivo evaluations, TOCN 0.2 hydrogel significantly reduced peritoneal adhesion in rat (n = 8) compared to untreated controls based on gross observation, histological analysis, and expression analysis of marker proteins. By taking advantages of thermo gelling, high stability, non-invasive way of application and rapid recovery potential, TOCN containing bio compatible hydrogel could be used as a cost-effective barrier to efficiently inhibit post-surgical peritoneal adhesions.

Evaluation on antithrombotic effect of aspirin eugenol ester from the view of platelet aggregation, hemorheology, TXB2/6-keto-PGF1α and blood biochemistry in rat model

Background

Based on the prodrug principle, aspirin and eugenol, as starting precursors, were esterified to synthesize aspirin eugenol ester (AEE). The aim of the present study was to evaluate the antithrombotic effect of AEE in an animal disease model. In order to compare the therapeutic effects of AEE and its precursors, aspirin, eugenol and a combination of aspirin and eugenol were designed at the same molar quantities as the AEE medium dose in the control group.

Methods

After oral administration of AEE (dosed at 18, 36 and 72 mg/kg) for seven days, rats were treated with k-carrageenan to induce tail thrombosis. Following the same method, aspirin (20 mg/kg), eugenol (18 mg/kg) and 0.5 % CMC-Na (30 mg/kg) were administered as control drug. Different drug effects on platelet aggregation, hemorheology, TXB₂/6-keto-PGF_1α ratio and blood biochemistry were studied.

Results

AEE significantly inhibited ADP and AA-induced platelet aggregation in vivo. AEE also significantly reduced blood and plasma viscosity. Moreover, AEE down-regulated TXB₂ and up-regulated 6-keto-PGF_1α, normalizing the TXB₂/6-keto-PGF_1α ratio and blood biochemical profile. In comparison with aspirin and eugenol, AEE produced more positive therapeutic effects than its precursors under the same molar quantity.

Conclusion

It may be concluded that AEE was a good candidate for new antithrombotic and antiplatelet medicine. Additionally, this study may help to understand how AEE works on antithrombosis in different ways.

Designing flexible energy and memory storage materials using cellulose modified graphene oxide nanocomposites

The demand for flexible energy storage devices is ever increasing, and several polymer nanocomposites are widely used to fabricate them.