• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.5
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• pp.539-543
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• 2012

Cellulose Electro-Active Paper (EAPap) is attractive as a biomimetic actuator because of its merits: it is lightweight, operates in dry conditions, has a large displacement output, has a low actuation voltage, and has low power consumption. Cellulose is regenerated so as to align its microfibrils, which results in a piezoelectric paper. When chemically bonded and mixed with carbon nanotubes, titanium oxide, zinc oxide, tin oxides, the cellulose EAPap can be used as a hybrid nanocomposite that has versatile properties and that can meet the requirements of many application devices. This paper presents trends in recent research on the cellulose EAPap, mainly on material preparation and its use in devices, including biosensors, chemical sensors, flexible transistors, and actuators. This paper also explains wirelessly driving technology for the cellulose EAPap, which is attractive for use in biomimetic robotics and micro-aerial vehicles.

• Applied Chemistry for Engineering
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• v.34 no.1
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• pp.57-63
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• 2023

In this study, an organic-inorganic hybrid composite of Abaca nanocellulose and titanium dioxide was prepared. Abaca nanocellulose was prepared by oxidizing Abaca cellulose using TEMPO (2,2,6,6-tetramethyl-piperidine-1-oxyl) as a catalyst. Titanium dioxide nanoparticles were prepared by the sol-gel method, and a composite was prepared by hybridizing them with nanocellulose. As a result of comparing the properties of the composite and its physical properties according to the change in manufacturing pH, the effect of pH was very large when combining nanocellulose and titanium dioxide, and the optimal bonding performance was shown at pH 8 in this experimental condition. In addition, the prepared composite showed photocatalytic properties, and the higher the content of titanium dioxide, the higher the hydrophilicity of the composite according to UV light irradiation.

• Applied Chemistry for Engineering
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• v.16 no.2
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• pp.257-261
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• 2005

The microbial cellulose is in a form of three dimensional net structures that consists of 20~50 nm fibrils. It possesses high crystallinity and orientation. It is difficult to synthesize large amount of fibrous carbon nanomaterials by the carbonization process using raw materials such as polyacrylonitrile (PAN), regenerated cellulose (Rayon) and pitch. However, it seems possible thru the application of microbial cellulose as raw material. The application of such cellulose can be further extended to the synthesis of highly oriented graphite fiber. Out of three different cellulose-producing strains, G. xylinus ATCC11142 was chosen as it has the highest productivity (0.066 g dried cellulose/15 mL medium). Tar is often produced during the carbonization of cellulose that limits the formation fibrous structure of the carbonized sample. In order to solve such a problem, pre-studied purification methods of carbon nanotube such as liquid phase oxidation, gas phase oxidation and filtration associated with ultrasonication were applied at the carbonized cellulose. In that case. only by filtration associated with ultrasonication, improved the formation of fiber structure of the carbonized cellulose.

• Journal of the Korean Wood Science and Technology
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• v.42 no.4
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• pp.376-384
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• 2014

This study investigated the effect of nanocellulose, such as microfibrillated cellulose (MFC) and cellulose nanocrystal (CNC), and aminated starch on tensile property and thermal stability of plasticized starch film. Glycerol (23 wt%) was used as a plasticizer and nanocelluloses of 1-30 parts per hundred parts of resin (phr) in the basis of plasticized starch were added. Tensile strength and elastic modulus increased with increasing nanocellulose addition amount, whereas elongation at break decreased. Tensile properties of MFC-reinforced starch film were higher than those of CNC-reinforced film. Optimum addition amount of aminated starch, which is commonly used for paper sizing, to improve tensile property of film, was found to be 5%. And 1% addition of aminated starch showed the best effect in the improvement of tensile property of the film. Thermal stability was improved with the addition of MFC to plasticized starch film with and without aminated starch.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.4
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• pp.469-477
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• 2021

In this study, the mechanical property of anti-fouling coating using CNF was evaluated to prevent the durability and stability of structure exposed the marine environment. Anti-fouling coating using CNF was prepared by CNF, AKD and waste glass powder, and contact angle test, drying time, viscosity analysis and microstructure were performed. When coating on one number of times, It was showed to relatively high hydrophobic performance in steel. And It was confirmed that the contact angle increased as the content of AKD increased in cement mortar. When coating on three number of times, the surface was confirmed super-hydrophobic at maximum of 151.6°. When mixing waste glass powder, the surface was showed to relatively high hydrophobic. It is pseudo plastic fluid when CNF and distilled water were prepared in a ratio of 1:1, And Anti fouling coating is judged to be suitable for use as coating on marine structure.

• NICE (News & Information for Chemical Engineers)
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• v.34 no.5
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• pp.500-500
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• 2016

• Journal of the Korean Wood Science and Technology
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• v.40 no.3
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• pp.156-163
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• 2012

This research has been carried out to investigate the characteristics of cellulose nanofibers manufactured from domestic lignocellulosic materials by mechanical grinding method. The continuous grinding process was effective for loosening cell wall structure, with increasing grinding time, much smaller nanofibers were observed. Filtration time was linearly increased with increasing grinding time for all experimental materials. Relative crystallinity of cellulose was not changed by grinding process, but increased by delignification treatment. Tensile property of fiber sheets was drastically improved with increasing grinding time. Fibers sheets obtained from delignified cone stalks showed an excellent tensile strength. Consequently, it is considered that this study presented some effective information for manufacturing cellulose nanofibers with domestic plantation resources.

• KSBB Journal
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• v.20 no.1 s.90
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• pp.50-54
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• 2005

Tar is often produced during the carbonization of cellulose that limits the formation fibrous structure of the carbonized sample. This problem was reduced by applying a high temperature $(up\;to\;800{\circ}C)$ during carbonization process. Alternatively, dry cellulose was immersed in toluene and ultrasonicated prior to carbonization. In both cases, complete fibrous structures were not achieved. The formation of tar was reduced by the heat treatment of cellulose in the presence of HCI vapor before carbonization process. Such treatment before carbonization yielded mostly the fibrous structures of the carbonized sample as evident from SEM analysis. Similar results were found when the cellulose was subjected to a heat treatment in an inert condition followed by the removal of tar by the oxidation process prior to the carbonization.

• Polymer(Korea)
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• v.28 no.6
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• pp.551-555
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• 2004

Cellulose diacetate (CDA) nanocomposite films were prepared by using various plasticizer and montmorillonite nanofiller in methylene chloride/ethanol (9:1 w/w) mixed solution. The thermal property (T$_{g}$) of prepared CDA films was observed by DSC and T$_{g}$ of the films was decreased with the increase in the plasticizer content. The degree of dispersion of MMT in the CDA film was observed by XRD and mechanical property of CDA film was measured by tensile strength and Young's modulus. When the plasticizer was added into the CDA film upto 30 wt%, the Young's modulus of film was decreased from 1930 MPa to 1131 MPa but was increased from 1731 MPa to 2272 MPa when the MMT was added into the film upto 7 wt%. The mechanical properties of CDA films were decreased by addition of plasticizer but strengthened by the incorporation of MMT.

• Composites Research
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• v.36 no.2
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• pp.126-131
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• 2023

Growing environmental concerns regarding pollution caused by conventional plastics have increased interest in biodegradable polymers as alternative materials. The purpose of this study is to develop a 100% biodegradable nanocomposite material by introducing organic nucleating agents into the biodegradable and thermoplastic resin, poly(lactic acid), to improve its properties. Accordingly, cellulose nanofibers, an eco-friendly material, were adopted as a substitute for inorganic nucleating agents. To achieve a uniform dispersion of cellulose nanofibers (CNFs) within PLA, the aqueous solution of nanofibers was lyophilized to maintain their fibrous shape. Then, they were subjected to primary mixing using a twin-screw extruder. Test specimens with double mixing were then produced by injection molding. Differential scanning calorimetry was employed to confirm the reinforced physical properties, and it was found that the addition of 1 wt% CNFs acted as a reinforcing material and nucleating agent, reducing the cold crystallization temperature by approximately 14℃ and increasing the degree of crystallization. This study provides an environmentally friendly alternative for developing plastic materials with enhanced properties, which can contribute to a sustainable future without consuming inorganic nucleating agents. It serves as a basis for developing 100% biodegradable green nanocomposites.