Papers by Keyword: Bacterial Cellulose

Abstract: The high demand for cellulose paper made from hardwood (trees) is currently causing environmental damage because the hardwood used comes from logging a very large amount of land. This tree felling, if continuously carried out, will result in natural disasters such as floods, landslides and the extinction of some animals due to homelessness, on a large scale can also result in climate change globally due to an increase in geothermal temperatures. This study synthesised TKKS waste mixed with bacterial cellulose with a combination of 100%, 75%, 50%, and 25% with the addition of CMC additives to strengthen the morphological quality of the resulting paper surface. The purpose of this study is to process cellulose fibres from TKKS waste mixed with bacterial cellulose reinforced with CMC additives to produce environmentally friendly paper. The addition of CMC additives is intended to improve the morphological properties of the paper surface that has been produced. So that the products produced are expected to have the potential to reduce dependence on paper made from hardwood (trees). The target of this research is to produce products that can be implemented as replacement paper that can be used in the graphic industry and society. The methods used in this study are a combination of mechanical processes, chemical processes, and chemical mechanical combinations. Then Next, conduct a paper feasibility test for writing and printing produced. Paper base material characterization test, paper surface morphology test is carried out to determine the quality of the paper produced.

Abstract: In this study, zinc dross (ZD) was used as precursor to prepare hematite/zinc oxide (Fe₂O₃/ZnO) nanocomposites with bacterial cellulose (BC) as catalyst support to prevent agglomeration of the obtained Fe₂O₃/ZnO. pH during the dissolution process of ZD was varied at 4.2 and 5.5 (namely ZD4 and ZD5, respectively) to know the effect of pH on the formation of Fe₂O₃/ZnO/BC. As comparison, Fe₂O₃/ZnO from its pure precursor was also prepared with the same pH and Zn concentration of ZD4 and ZD5 (namely ZF4 and ZF5, respectively). Atomic absorption spectroscopy (AAS) results showed that Zn and Fe content in ZD4 sample (42,059 and 8,615 ppm, respectively) are higher than Zn and Fe content in ZD5 sample (25,554 and 2,204 ppm, respectively). X-ray diffraction (XRD) and Fourier transform infra-red (FTIR) results of all samples confirmed the successful synthesis and deposition of Fe₂O₃/ZnO on BC. Scanning electron microscope (SEM) results revealed that the average particle size of Fe₂O₃/ZnO/BC samples at pH 5.5 (341 nm for ZD5 and 385 nm for ZF5 samples respectively) are slightly smaller than samples at pH 4.2 (418 nm for ZD4 and 426 nm for ZF4 samples respectively). Photocatalytic activities results showed that Fe₂O₃/ZnO/BC samples at pH 5.5 (45.7% for ZD5 and 57.9% for ZF5 samples respectively) have slightly higher activity than samples at pH 4.2 (38.1% for ZD4 and 41.9% for ZF4 samples respectively). These findings demonstrate the potential use of ZD and suggest that dissolution of ZD at pH 5.5 led to smaller particles size and higher photocatalytic activity than pH 4.2.

Abstract: Cellulose is an important structural material found naturally within the cell walls of plants that has recently been researched as a biodegradable, renewable, and non-toxic reinforcing agent used to improve properties for a variety of composite systems. Cellulose is usually derived from wood sources via acid hydrolysis. Bacterial cellulose (BC) is produced by bacteria proliferation using nitrogen, carbon, and oxygen sources, and is similar chemically to plant extracted cellulose. Compared to commercially available cellulose, BC has higher purity and increased hydrophilicity. In this work, banana peels are used as a carbon source for bacterial cellulose growth. The peels were heat treated to maximize sugar and carbon contents. In addition, BC derived from the banana peels doesn’t require any bleaching or chemical post-processing. In this research, BC derived from banana peels is synthesized, characterized, and analyzed for its physical, mechanical, and thermomechanical properties, as compared to commercial nanocellulose.

Abstract: This paper discusses the wear behavior of self-mated AISI52100 bearing steel lubricated by polyol ester containing additives of bacterial cellulose particles. The wear properties are compared to those of surfaces lubricated by the base fluid without the additive. The sliding tests were conducted using a pin-on-disk reciprocating tribometer at room temperature. The results indicate that after a sliding distance of 72 meters, the friction coefficient was relatively similar for both lubricant conditions. However, the wear of the material was significantly reduced with the presence of cellulose particles in the lubricant, improving it by almost 100%. Observation of the worn area of the pin indicates the formation of a tribofilm on the contact interface facilitated by the cellulose particles. EDX analysis revealed that the film comprises oxygen and carbon-rich elements. It seems that the tribo-layer formed by a tribo-chemical reaction during sliding has acted as a protective barrier, preventing surface material ploughing and reducing wear on the tribo-pair.

Abstract: Nanocomposites derived from biomaterials are crucial in advancing sustainable and innovative functional materials for diverse applications, including environmental remediation and wastewater treatment. In this paper, we report the fabrication of a magnetic composite derived from magnetic iron oxide nanoparticles (MIONPs) and bacterial cellulose (BC) for the photocatalytic degradation of organic pollutants in water. The magnetic films were fabricated by in situ co-precipitation of MIONPs into the BC matrix. Fourier transform infrared spectroscopy revealed the presence of Fe-O vibrations in the nanocomposite. Scanning electron microscopy and energy-dispersive X-ray spectroscopy further confirmed the presence of MIONPs on the surface of the bacterial cellulose, indicating the successful integration of MIONPs into the matrix. X-ray diffraction pattern of the nanocomposite exhibited the crystalline features of the MIONPs. The photodegradation capacity of the magnetic BC films was evaluated using methylene blue (MB) as a model organic pollutant. Results revealed the photodegradation efficiencies of approximately 68% and 73% after 120 mins of irradiation under ambient and ultraviolet (UV) light, respectively. Early onset of dye degradation saturation was also observed for samples exposed to ambient light condition. No significant changes in the optical absorption of the dye when treated with BC only with and without illumination, suggesting that the photocatalytic effect is primarily due to the MIONPs. This work presents a promising strategy for utilizing biological resources such as bacterial cellulose as a hybrid material for environmental and other advanced applications.

Abstract: Bacterial nanocellulose (BNC) is a natural polymer gel with unique properties that are suitable for developing advanced film applications such as edible coating and packaging. However, transforming BNC gel into a suspension and applying it as a film still lacks knowledge of the condition and method since BNC film performance depends on many parameters caused by the transformation process. This work studied two important primary variables, the number of homogenization cycles and the BNC concentrations, for transforming BNC gel into aqueous suspension using a microfluidizer to homogenize nanofibers and water medium. The BNC films obtained from the suspensions were examined for their properties, i.e., morphology, crystallinity index, optical, thermal, and mechanical properties. The results explored that the number of homogenization cycles had a non-significant impact on the characteristics and properties of BNC suspension and film. A significant improvement in film properties was found when using a higher BNC concentration at 1% w/v compared with 0.5% w/v at the equivalent number of homogenization cycles (40 cycles). The degradation temperature of this film increased by 13%, and Young’s modulus and tensile strength increased more than twice compared with the 0.5% w/v sample, increasing from 0.3 to 0.7 MPa and from 9 to 19 kPa, respectively. This finding would benefit the further development of BNC film for coating and packaging applications.

Abstract: Microbeads are primary microplastics made from synthetic polymers and are widely applied in cosmetics and personal care products. This wide application led to an increase in microbead production in 2020 from 2.3 billion USD to 3.5 billion USD in the global market, and the growth is directly proportional to the waste generated. Microbeads cannot be filtered by sewage treatment because of their small size, and materials made of synthetic polymers are difficult to degrade by the environment. It is possible to use bacterial cellulose (BC) as a raw material for the production of microbeads because of its physical features and its capacity to break down in the environment. In this review, the best method used for BC synthesis is mechanical fragmentation and drying using ambient pressure drying. BC had also impregnated using Moringa leaf extract to improve its physical properties and usability. After the BC microbeads have been produced, BC degradation analysis can be solved using mechanical degradation. Furthermore, the degradation kinetics of BC microbeads can be determined using the Ekenstam equation, surface degradation kinetics, and elementary reactions (zero, first, second, and third-order equations). The kinetic model of BC microbead degradation will be obtained based on the highest linear regression equation.

Abstract: Thermoplastic starch bio-composite compound of cross-linked cassava starch has been produced by a twin screw extruder. Rice husk powder, bacterial cellulose fiber and glycerol were incorporated into the starch at various compositions. Bio-composite compounds were thermally compressed into a mechanical test specimen. Influences of reinforcing materials and plasticizer contents were investigated. An extrusion (160°C) and compression (200°C) at higher temperature produced a greater structural deformation of the cross-linked starch than a processing at lower temperature. Morphology of the bio-composite showed a homogeneous distribution of reinforcement in the matrix at high temperature processing and showed good adhesion between rice husk particle, bacterial cellulose fiber and starch matrix. Flexural and tensile mechanical properties of the bio-composite significantly improve with only 0.71%wt bacterial cellulose incorporation.

Abstract: Cellulose acetate is a promising thermoplastic polymer to be developed since it has some characteristics, among others are easy to be formed, non-toxic, high stability, and its raw materials are renewable. The most used source of cellulose acetate raw material is bacterial cellulose because bacterial cellulose has the higher purity and the process cost is lower rather than plant cellulose. Nowadays, the production of bacterial cellulose is highly developed using coconut water media. Nevertheless, coconut water costs expensive and the supply is rare. Materials that are being potential to be developed as raw materials of bacterial cellulose through fermentation process is palm flour liquid wasted since it contains high amounts of carbon and nitrogen. This study began with the synthesis of bacterial cellulose from palm flour oil liquid waste and coconut water using Acetobacter xylinum bacteria and then cellulose acetate is synthesized through an acetylation reaction. This study aims to determine the optimum acetylation time on its performance as a reinforcement filler to be applied as a packaging material. Based on the results of Scanning Electron Microscopy and Fourier Transform Infra-Red analysis on predetermined variables, it resulted particles in the form of bacterial cellulose and cellulose acetate with the highest yield of cellulose acetate at 3 hours of acetylation was 94.74%.

Abstract: Water holding and release properties are important characteristics for a dressing material in wound healing. In the present study, the water holding capacity (WHC) and water release rate (WRR) of BC films produced from oil palm frond (OPF) juice were investigated. The juice was inoculated with Acetobacter xylinum in 24-well plates and incubated at 30 °C for 7 days under static conditions. The films were further dried by three different methods; air-, oven-and freeze-drying. The dried BC was characterized for its size and surface morphology by field emission-scanning electron microscopy (FE-SEM) and for its water holding and release properties. BC produced from OPF juice exhibited good WHC and WRR comparable to BC films produced from Hestrin and Schramm (HS) medium. The loosely arranged fibrils in freeze-dried BC has also resulted in highest WHC and WRR value compared to the oven-and air-dried BC. This study suggested that water holding and release properties are greatly dependent on the use of fermentation medium and drying method.