Papers by Keyword: Cellulose

Abstract: This study provides accounts of the bonding character, electronic structure, and optical properties of the cellulose–polyaniline hybrid complex using principles of quantum mechanics. The calculations revealed cellulose and polyaniline binding energy per unit ranged from -0.52 eV to -0.68 eV. The electron localization function of the complex revealed that there was no value at the interface but deformed basins, indicating a physisorption type of interaction. The highest occupied molecular orbitals and lowest molecular orbitals are mainly dominated by the polyaniline, with minor hybridization of the orbitals of the cellulose in all configurations. These results indicate that the bonding between cellulose and polyaniline is characterized as an unshared electron interaction. Generally, the density of states of the cellulose and polyaniline complex can be considered a superposition of the states of isolated subsystems—the bandgap of the complex ranges from 2.30 eV to 2.87 eV. The lowest bandgap is observed when the prototype polyaniline is placed near the cellulose hydroxy and hydroxymethyl group. Further, the optical absorption spectra are calculated using time-dependent density functional theory. The results indicate that the prominent peak of the prototype polyaniline at 3.59 eV (345.36 nm) is suppressed at the complex. Meanwhile, in the higher energy region, the optical absorption spectra can be considered a superposition of the absorption spectra of the isolated constituents. The results presented here provide new information on the cellulose–polyaniline complex's bonding mechanism and give the resulting electronic–optical properties. The results will be helpful in the development of innovative biomaterials, fibers, and multifunctional composites based on cellulose and polyaniline.

Abstract: In this research, the researchers successfully fabricated photocatalysts hybrid materials using g-C₃N₄ microrods and g-C₃N₄ nanosheets, which were coated on water hyacinth cellulose sponges. The optical properties of the photocatalysts hybrid materials, specifically the g-C₃N₄ microrods and g-C₃N₄ nanosheets, were analyzed using a UV-vis spectrometer. The morphology of the g-C₃N₄ microrods and g-C₃N₄ nanosheets photocatalysts was examined using different procedures, including FTIR (Fourier-transform infrared spectroscopy), XRD (X-ray diffraction), and TEM (transmission electron microscopy). The results obtained from the study indicate that g-C₃N₄ microrods exhibited a higher level of crystallinity or orderliness in terms of intramolecular orientation compared to g-C₃N₄ nanosheets. This suggests that the microrods possessed a more organized arrangement of atoms within the material structure. Furthermore, the energy bandgap values, as determined from the study, were found to be 2.25 eV for the microrods and 2.75 eV for the nanosheets. As part of this project, the photocatalysts, namely g-C₃N₄ microrods and g-C₃N₄ nanosheets, were utilized as coating materials for water hyacinth-synthesized cellulose sponges. This process led to the formation of hybrid materials known as g-C₃N₄ MCS (Microrods Cellulose Sponge) and g-C₃N₄ NCS (Nanosheets Cellulose Sponge). The efficiency and reaction rate of MB removal were then studied with various models such as First order reaction, Second order reaction, Pseudo first order reaction, Pseudo second order reaction and Elovich model. The results obtained from the research project indicated that the g-C₃N₄ NCS hybrid material exhibited a notably higher rate of organic degradation compared to the g-C₃N₄ MCS hybrid material. In conclusion, this research project successfully achieved the fabrication and characterization of a photocatalysts hybrid material using cellulose sponge from water hyacinth. The material demonstrated excellent performance as an absorbent and degradation agent for organic pollutants in water, highlighting its potential for practical applications in water treatment and environmental remediation.

Abstract: Cellulose is a natural polymer with good properties that have caught researchers' attention to utilize these natural resources' potential. Cellulose also has been widely used as an alternative filler to replace inorganic filler in polymer composites. This review discussed the extraction of cellulose from oil palm empty fruit bunch (OPEFB). This review focused on the OPEFB due to the emergence of palm oil plantations which creates a high amount of biomass, whereas OPEFB is one of the major contributors. The utilization of cellulose application in the polymer focused on alternative fillers in latex application. The postulate crosslink mechanism in latex films is also described to highlight the potential of OPEFB as fillers in latex application. The utilization of OPEFB cellulose has the potential to be explore as bio-fillers with also impact the crosslinks mechanism in latex system which can improved the properties in latex composites.

Abstract: Oil palm empty fruit bunches (OPEFB) are oil palm industry waste which is indeed abundant. OPEFB waste has been explorated to make fiber, cellulose, and its derivatives. In the process of extracting cellulose, there is depolymerization of several components, both hemicellulose, lignin, color, and structural elements. The combination of bleaching under acidic conditions and alkaline delignification gave different changes, one of which depends on the type of bleacher, concentration, reaction time, and the number of stages carried out. This study aimed to examine the effect of NaClO₂ concentration and bleaching time on the physical and chemical characteristics that indicate the depolymerization process of OPEFB fiber. Depolymerization can be indicated by changes in the cellulose color, the content of cellulose, and the changes in cellulose crystallinity. The change of cellulose mass was affected by the bleacher concentration and the bleaching time. High concentrations of bleacher will reduce the cellulose mass significantly. Similarly, the depolymerization of the chromophore elements in OPEFB fiber will show a change in color from brown to gray-white with different brightness intensities. The XRD test indicated that there was a correlation between low crystallinity with the use of high bleacher concentrations.

Abstract: The population growth and the industrial revolution caused severe environmental pollution, especially pollution of clean water availability. Several ways have been conducted to overcome the pollution of clean water availability, one of which is by the adsorption of metal and cellulose-based waste materials as a hybrid catalyst. This study aims to fabricate and modify a hybrid catalyst composed of cellulose in the form of nanosized fibrils. Cellulose can be used as a catalyst by incorporating Fe from magnetite (Fe₃O₄) and can work effectively as an adsorbent for methylene blue (MB) dye waste. The method used in this research is a modified coprecipitation method by combining cellulose and Fe₃O₄ nanoparticles. Hybrid Catalyst of Fe₃O₄/Cellulose Nanocomposite-Base has been successfully characterized by using XRD, SEM-EDX, and UV-Vis, respectively to determine the particle structure, morphology, and adsorption capacity of the sample. The results of data analysis showed that Fe₃O₄/Cellulose could purify MB solution depending on the ratio of Fe₃O₄ and the mass of cellulose used. The higher the mass ratio of cellulose to Fe₃O₄, the absorbance value of the Fe₃O₄/Cellulose nanoparticle sample increases.

Abstract: The main purpose of this study is to synthesize nano-hydroxyapatite/cellulose (nHAP/Cel) and nano-hydroxyapatite/chitosan (nHAP/CS) scaffolds via co-precipitation method for bone tissue engineering due to their suitable biocompatibility, cytotoxicity and mechanical properties. The characterizations of these scaffolds were investigated by Infrared absorption spectra (FT-IR), X-ray Diffraction (XRD), and Scanning Electron Microscope (SEM). The cytotoxicity of these nanoparticles was evaluated with bone marrow cell using the 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyl-tetrazoliumbromide) (MTT) assay. The porosity of scaffolds was estimated 87%. The results indicate that the nano composite scaffolds have good morphology, tissue biocompatibility and biodegradability to be used for tissue engineering.

Abstract: Cellulose is one of the main components of plants, depending on the plants, the cellulose content can be up to 98%. Cellulose has a wide range of use. It can be used in the food industries, pharmacy, paper, and chemical industries. To extract the cellulose from biomass, the biomass needs to undergo a pre-treatment. This study uses steam explosion pre-treatment as it does not cause hazards to the environment, has low energy cost, and low investment cost. In this pre-treatment, steam will be injected into the biomass until the pressure reach 15 bar, then decline rapidly to make an explosion that causes damage to cellulose crystalline. After that, the process continues to main process, which are washing, and alcohol extraction. Then continued to alcohol recovery. After considering many factors, a cellulose plant from rice straw will be built in 2023 in industrial parks Java Integrated Industrial and Ports Estate or known as JIIPE with a capacity of 370,000 tons/ year. Based on economic analysis, this plant has an internal rate of return of 35.17% and a payout time of 3.98 years. This makes this plant feasible to be built.

Abstract: Oil palm empty fruit bunch fibre (OPEFB) is a waste from palm oil mill. It is rich in useful compound residues such as cellulose and carboxymethylcellulose. The increasing interest in OPEFB as a source of cellulose is due to its low cost, renewable and abundantly available, particularly in the Southeast Asia region. Cellulose extraction is affected by pre-treatment, especially during the bleaching process. Thus, this study aims to analyse the effect of bleaching period and treatment using NaClO₂ on cellulose recovery from OPEFB. Batch process of bleaching was carried out in the ratio of 1:50 of fibres to sodium chlorite (NaClO₂) solution of 0.7%. This was followed by analysis of cellulose morphological using FTIR and SEM analysis. The study found that bleaching duration affects cellulose recovery, with the highest yield of 54% found to be at 3 hours of bleaching duration. The bleaching duration was increased up to 6 hours, but found to yield less cellulose, which indicated that certain duration is suitable to provide a condition for higher cellulose yield.

Abstract: Platinum (Pt), a noble metal, is known for its ability to regenerate and be recycled even without any reactivation procedure, and still demonstrated good stability. The cost of the noble metal can be reduced by incorporating the metal into the pores of catalyst support rather than using it individually. Hence, in this research study, 4 wt.% Pt supported on silica-alumina (SiO₂-Al₂O₃) and gamma-alumina (γ-Al₂O₃) was synthesized using wet impregnation method, then followed by catalyst calcination at 500 °C. The catalyst was then characterized using Thermogravimetric Analysis (TGA), Fourier-Transform Infrared Spectroscopy (FTIR), Brunauer–Emmett–Teller (BET), and particle size analyzer where catalyst with high surface area and pore volume demonstrated an excellent performance for the catalytic reaction of cellulose. Experimental results showed that catalyst Pt/SiO₂-Al₂O₃ with the highest surface area and pore volume (466.4 m²/g and 0.1157 cm³/g, respectively) exhibited the highest catalytic performance with the conversion of cellulose up to 65.8% and 30.9% levulinic acid (LA) yield produced at the reaction temperature of 200 °C in a semi-batch reactor for 8 hrs.

Abstract: Cellulose modification is a challenge due to molecules characteristics – equatorial conformation, hydrogen bonds both withing molecule and among neighboring molecules etc. Esterification of cellulose hydroxyl groups (-OH) with dicarboxylic compounds is challenging. In presented study simple modification with maleic anhydride is performed in an anhydrous environment. Scanning electron microscopy reveals clean fibers of cellulose-maleic anhydride derivatives. FTIR proves unique peak at 1735cm^-1 that corresponds to ester carbonyl groups. Titration of carboxylic (-COOH) groups solidifies that one part of anhydride has bonded with cellulose and other carboxylic groups is accessible for further development.