Effect of Sodium Hydroxide/Urea/Deionised Water Solution Ratio on the Solubility of Oil Palm Empty Fruit Bunches Extracted Biocellulose

Biocellulose extracted from oil palm empty fruit bunches (OPEFB) is attracting increased research interest in versatile applications as an alternative material to synthetic cellulose. Normally, biocellulose needs to undergo dissolution prior its applications. Among all explored solvents to dissolve biocellulose, aqueous sodium hydroxide (NaOH)/urea solution is gaining increased attention. OPEFB biocellulose solubility in NaOH/urea/deionised (DI) water solution has not been fully studied by researchers. This study aimed to investigate the solubility of OPEFB biocellulose in NaOH/urea/DI water solution by manipulating the NaOH/urea/DI water solution ratio and weight percentage of OPEFB biocellulose. Results indicated that increasing the NaOH/urea/DI water solution ratio increased the solubility of OPEFB biocellulose. Further increased NaOH/urea/DI water solution ratio resulted in decreased solubility. Meanwhile, increased OPEFB biocellulose weight percentage decreased the solubility of OPEFB biocellulose in NaOH/urea/DI water solution. The highest solubility of 70.89%±1.85% was exhibited by 7% NaOH/12% urea/81% DI water (w/w) solution and 1 w/v% OPEFB biocellulose. This study on OPEFB biocellulose solubility in NaOH/urea/DI water solution can promote cost-effective and wide utilisation of the abundantly available OPEFB for the synthesis of cellulose fibres, films, and hydrogels in the textile, packaging, and biomedical industries.

Silver-Chitosan Nanocomposite Prepared With Aqueous Sodium-hydroxide and Aqueous Acetic Acid Solutions: Characteristics and Their Cytotoxic Effects

In this study cytotoxic effects of silver-chitosan nanocomposites with aqueous sodium-hydroxide solution (SCNC-ASHS), and aqueous acetic acid solution (SCNC-AAAS) were evaluated, in vitro. The morphology of the synthesized nanoparticles were characterized by Fourier-Transform Infrared Spectroscopy (FTIR), and Scanning Electron Microscopy (SEM). Their cytotoxicity were then evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) in concentrations of 1.56 to 400 µg/ml, and acridine orange/ethidium bromide (AO/EB) staining after 24h and 48h. Results showed the cytotoxicity of 400 µg/ml of SCNC-ASHS on Vero and HT-29 cells of 80.57% and 84.37% after 24h, and 82.20% and 84.84% after 48h. While, the values for SCNC-AAAS on Vero and HT-29 cell-lines were respectively 80.63% and 87.64% after 24h, and 83.60% and 87.44% after 48h. The most toxicity on HT-29 cells was belonged to SCNC-AAAS with IC50 of 40.4 µg/ml. In the staining procedure, cell viability for 25 µg/ml concentration of SCNC-AAAS was 41.84% in HT-29 cell and, for 6.25 µg/ml of SCNC-AAAS was 37.51% in Vero cells. A considerable decrease in cell viability was observed. Types of nanoparticles, synthesis methods, and different cell lines play role in inducing cytotoxicity. Anti-cancer effect of the nanoparticles on the colon cancerous cells (HT-29), of that SCNC-AAAS displayed higher effect than SCNC-ASHS.

Potential Evaluation of PVDF/PAN Membranes for Separation of Oil from Industrial Waste

Aim: The aim of the experiment is to characterize the Modified Membrane from PVDF/PAN and its application in removing the Emulsified oil waste from the Industry. Objective: To get the maximum separation of the emulsified oil from the waste water, composite (PVDF/PAN) membrane was prepared in the laboratory. Methods: New PVDF/PAN blend based ultrafiltration membranes were synthesized by phase inversion method. The blend membrane was treated at room temperature with aqueous sodium hydroxide solutions. Results: The facile eco-friendly preparation of PVDF/PAN blended membrane has a wide potential for practical applications in emulsified wastewater remediation. The chemical functionality of the modified membranes was confirmed by IR spectra. Conclusion: For the separation of emulsified oily wastewater, the as-prepared composite (PVDF/PAN) membrane could effectively separate oil/ water emulsions with separation efficiency of above 99.8%. Unmodified membranes (A and B) showed 95.4-99.8% rejection. However, in the case of membranes C and D, oil rejection was higher for the modified membranes as compared to the unmodified membranes.

Extraction of cellulose nano-crystals from Polyalthia longifolia and Terminalia catappa leaf litter and the synthesis of low-cost CNC-based hydrogel for articular cartilage

Due to the rise in demand for biodegradable and renewable materials, the synthesis of CNCs from lignocellulosic biomass opens up a new avenue for the creation and application of novel materials in nanotechnology. The CNC-based hydrogels appear to be a favorable material in various applications due to their excellent mechanical strength, biodegradability, biocompatibility, and low toxicity. This work aimed to utilize the fallen leaves for the extraction of Cellulose Nano-crystals (CNC) from Polyalthia longifolia and Terminalia catappa leaf litter. Leaves mainly consist of cellulose hence used for the extraction of nanocellulose. Alkali treatment was performed with aqueous sodium hydroxide, followed by bleaching with aqueous sodium chlorite. Sulphuric acid hydrolysis was used for the extraction of CNC. The morphology, structure, functional groups, and crystallinity of the retrieved CNC were studied using a Transmission Electron Microscope (TEM), Fourier Transformed Infrared spectroscopy (FTIR), and X-Ray Diffraction (XRD). The shape was rod-like for both P. longifolia and T. catappa and the CNC’s crystallinity index was enhanced to 72.40% and 73.95%, respectively. The TEM micrographs revealed that the impurities present on the leaf fibres were successfully removed by alkali treatment and subsequent bleaching further purified the fibres, leaving behind mostly cellulose while the hemicellulose and lignin were removed, which was revealed in FTIR spectra. The obtained CNC was used in the preparation of hydrogel by cross-linking with natural polymers like sodium alginate and gelatin. A Freeze-thawing process was carried out for the fabrication of hydrogel. The resulting hydrogel can be used as a substitute for cartilage applications.

Carbon Adsorbents from Spent Coffee for Removal of Methylene Blue and Methyl Orange from Water

Activated carbons (ACs) were prepared from dried spent coffee (SCD), a biological waste product, to produce adsorbents for methylene blue (MB) and methyl orange (MO) from aqueous solution. Pre-pyrolysis activation of SCD was achieved via treatment of the SCD with aqueous sodium hydroxide solutions at 90 °C. Pyrolysis of the pretreated SCD at 500 °C for 1 h produced powders with typical characteristics of AC suitable and effective for dye adsorption. As an alternative to the rather harsh base treatment, calcium carbonate powder, a very common and abundant resource, was also studied as an activator. Mixtures of SCD and CaCO3 (1:1 w/w) yielded effective ACs for MO and MB removal upon pyrolysis needing only small amounts of AC to clear the solutions. A selectivity of the adsorption process toward anionic (MO) or cationic (MB) dyes was not observed.

The Improving properties of Viscose fabric by water repellent finish

Viscose as cellulosic origin, the cheapest of all cellulosic fabrics could be the best alternative. Viscose is manufactured from regenerated cellulose. In order to manufacture viscose, pulp of bamboo is treated with aqueous sodium hydroxide to form alkali cellulose. This alkali cellulose is then treated with carbon disulfide to form sodium cellulose xanthate. The xanthate is then dissolved in aqueous sodium hydroxide and allowed to depolymerize. After depolymerization, rayon fiber is produced from the ripened solution. Viscose is primarily employed in apparels, upholstery fabric, industrial clothing, and medical hygiene. Apparels, upholstery fabric, and industrial clothing segments account for key share of the viscose market. The medical hygiene segment is anticipated to expand during the forecast period. Demand for viscose fiber is anticipated to increase significantly in the near future due to the rise in global population, increase in standard of living, and growth in disposable income. Viscose is an eco-friendly product; thus, increase in awareness about eco-friendly products and decrease in production of cotton are estimated to augment the demand for viscose fiber. Viscose fabric exhibits some similar properties compared to cotton except its poor wet strength due to higher moisture regain. In this study, chemical finishes by different cross-linkers were applied to improve the wet strength of the viscose fabric. For this purpose, water repellent finishes were applied. Water repellent finish helped in reducing the molecular barrier around the individual fibres that lowered the surface tension of the fabric. It reduces the absorbency of viscose fabric hence leads to higher wet strength. Therefore, the treated viscose fabric exhibited better wet strength after applying water repellent finishes on it. Scanning electron microscope (SEM) was used to examine the surface of the fabric treated with chemicals. Tensile strength of viscose was increased 24.6%.

Strengthening Regenerated Cellulose Fibers Sourced from Recycled Cotton T-Shirt Using Glucaric Acid for Antiplasticization

The recycling of cellulose from cotton textiles would minimize the use of virgin crop fibers, but recycled polymers are generally inferior in mechanical performance to those made from virgin resins. This challenge prompted the investigation of biobased additives that were capable of improving the mechanical properties of fibers by means of antiplasticizing additives. In this study, regenerated cellulose (RC) fibers were spun from cellulose found in cotton T-shirts, and fibers were mechanically strengthened with glucaric acid (GA), a nontoxic product of fermentation. The recycled pulp was activated using aqueous sodium hydroxide and then followed by acid neutralization, prior to the direct dissolution in lithium chloride/N,N-dimethylacetamide (LiCl/DMAc) at 3 wt.% cellulose. At 10% (w/w) GA, the tensile modulus and strength of regenerated cellulose from recycled cotton fibers increased five-fold in contrast to neat fibers without GA. The highest modulus and tenacity values of 664 cN/dtex and of 9.7 cN/dtex were reported for RC fibers containing GA.

(E)-3-(4-Chlorophenyl)-1-(2-fluoro-4-methoxyphenyl)-2-propen-1-one

Natural products known as chalcones show promise as chemotherapeutic agents for the neglected tropical disease known as leishmaniasis. Our objective is to synthesize new targets of opportunity that may lead to better treatments of this debilitating disease. Claisen-Schmidt condensation of 4-chlorobenzaldehyde with 2′-fluoro-4′-methoxyacetophenone using aqueous sodium hydroxide in ethanol yielded the novel compound (E)-3-(4-chlorophenyl)-1-(2-fluoro-4-methoxyphenyl)-2-propen-1-one. The product was obtained in good yield and purity after recrystallization from ethyl acetate/hexane. With the known antiparasitic properties of halogenated chalcones, this novel compound is suitable for antileishmanial activity study.

Enhancing biocompatibility of PCL/PU nano-structures to control the water wettability by NaOH hydrolysis treatment for tissue engineering applications

Nano-structures due to their unique properties can provide a biomimetic structure for cell attachment and proliferation in tissue engineering (TE) applications. But sometimes, their surface properties are not particularly suitable for directed tissue growth. In this regard, present study has focused on fabrication and hydrolysis of Poly ( ε-caprolactone) (PCL)/Polyurethane (PU) by aqueous sodium hydroxide (NaOH) with a view to modify the surface and hydrophilicity of the structures. The characterizations and mechanical properties of non-hydrolyzed and hydrolyzed nano-structures were evaluated by SEM, FESEM, FTIR, water contact angle and tensile stress. The all hydrolyzed nano-structures showed improvement in contact angle after 2h at all concentrations of NaOH. The PCL, PU, PCL75%:PU25%, and PCL25%:PU75% structures have shown 3.8%, 12.5%, 4.1% and 7%, respectively, of shrinkage at hydrolysis at 3 M NaOH and 3 h. The PCL25%:PU75% structure indicated the greatest reduction in stress and strain at 3 M NaOH and 3 h (1.1 ± 0.06 MPa with 52% decreases) and (156 ± 5% with 49% decreases), respectively. Also, the structure with 75% of PCL showed 28% reduction in Young's Modulus (4.33 ± 0.45 MPa) at 3 M NaOH after 2 h. It is noted that the hydrolysis treatment with 3 M of NaOH concentration at 2 h is optimum condition for hydrolysis hybrid nan-structures for TE applications. Also, the results of this study proposed that hydrolyzed PCL75%:PU25% hybrid nano-structures due to its unique mechanical properties and optimum surface modification could be promising candidate for TE applications.