• Journal of the Korean Applied Science and Technology
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• v.32 no.1
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• pp.85-92
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• 2015

The 50 mole% HCl doped polyaniline(PAni) was synthesized by polymerization of aniline in the presence of hydrochloric acid and ammonium persulfate(APS) as dopant and oxidant, respectively. Then, conducting biodegradable cellulose acetate composite films were also prepared with PAni in acetone to find their applicability to antistatic packaging materials. The tensile strength of PCA05 film with 5 wt% of PAni was decreased by 27% from $377.1kg_f/cm^2$ for CA film itself to $275.2kg_f/cm^2$. Elongation was also decreased from 7.65% to 4.35%. Surface registance of $7.0{\times}10^9{\Omega}/sq$ could be achieved for the PCA containing 5 wt% of PAni. Therefore, this PCA05 film can be applied to antistatic package film for electronic board. In addition, decomposition temperature of these PCA films obtained by thermogravimetric analysis(TGA) was decreased with the amount of PAni in PCA films, and the final weight of char was directly proportional to PAni contents. From this thermal result we can calculate the content of PAni in unknown PCA films.

• Applied Biological Chemistry
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• v.45 no.4
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• pp.207-211
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• 2002

This study was conducted to increase the shelf life of grape by edible coating material such as methyl cellulose (MC) with antimicrobial substances, n-capric acid isopropyl ester (ci) and sodium nitrate (sn), added by spraying method. The quality changes of packaged grapes with wrapping PE film on EPS tray were investigated for 16 days at $30{\circ}C$. The shelf-lives of C and MCci based on the weight reduction ratio of 7% were 6 days and 9 days, respectively. The reduction rate of acidity of C was higher value than those of treatments during 18 days of storage at $30{\circ}C$. The vitamin C reduction ratios of C, MCsn and MCci were 64.8, 51.5 and 49.8%, respectively, after 16 days at $30{\circ}C$. The reduction rates of firmness of C, MCsn and MCci after 16 days at $30{\circ}C$ were 44.2, 26.5, and 23,2%, respectively compared to that of initial storage grapes. The additions of ci and sn had much affected the reductions of bacteria and yeast counts especially early stage of storage. The hedonic sensory evaluation scores of MCci and MCsn had higher values than those of MC.

• Polymer(Korea)
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• v.37 no.1
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• pp.52-60
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• 2013

Partially hydrolyzed cellulose acetate (CA) fibers were prepared by treating CA fibers in aqueous $Na_2CO_3$ solutions of various concentrations. The deacetylation of CA fibers was confirmed through FTIR spectra and WAXD patterns. The hydrolysis was confined to the surface part of the CA fiber by controlling the treatment conditions. The resultant fibers had a sheath-core structure with a sheath component of regenerated cellulose and a core of non-hydrolyzed cellulose acetate. The SEM images of the surface-hydrolyzed CA fibers, the core of which was dissolved out using acetone as the solvent, showed that the sheath thickness increased with increasing alkaline concentration, indicating an increase in the hydrolyzed fiber, i.e., regenerated cellulose. Polarized FTIR analysis of the polyimide film rubbed with velvet fabrics of surface-hydrolyzed CA fibers showed that polyimide molecules were preferentially oriented to the rubbing direction.

• Journal of Marine Bioscience and Biotechnology
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• v.14 no.2
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• pp.76-85
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• 2022

In this study, a biodegradable packaging film was developed using two marine algae, Gelidium amansii, and Sargassum horneri. The chemical properties and microstructure of the developed film were evaluated using field emission scanning electron microscope, Fourier transform infrared spectroscopy, gas chromatography-Mass spectroscopy, and thermogravimetric analysis. Furthermore, the mechanical properties and toxicity of the film were evaluated using the ISO 1924 and IEC 62321 methods, respectively. The biodegradability of the film was evaluated according to ISO 14855-1:2012 method. The film was primarily made of cellulose and had biodegradability that was about 17 times greater than that of PBS, a representative eco-friendly plastic. Moreover, the mechanical properties improved by approximately 40% compared to the seaweed-based film of the previous study. The virulence test revealed that the content of all of the toxic substances listed in IEC62321 was below the measurement limit. An egg carton that can be used in practice was manufactured in accordance with ISO 534, and its applicability was tested using the biodegradable packaging film prepared.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2004.04a
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• pp.240-243
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• 2004

• Polymer(Korea)
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• v.34 no.6
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• pp.560-564
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• 2010

Dimensional stability of LCD polarization film consisted of triacetyl cellulose (TAC) and poly(vinyl alcohol) (PVA) film has been studied and especially, the effect of PVA adhesive on the dimensional stability has been considered as function of deacetylation and molecular weight of PVA adhesive. The maximum adhesion strength between TAC and PVA film was obtained in the laminate using PVA adhesive with 70% of OH content and the effect of molecular weight on the adhesion strength was only pronounced in the laminate using PVA adhesive with OH content above 70%. It was found that the optimum dimensional stability of TAC/PVA/TAC laminate (polarizing film) was obtained when applied PVA adhesive has low molecular weight and it was more dependent upon the OH content than the adhesion strength between TAC and PVA films.

• Korean Chemical Engineering Research
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• v.54 no.4
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• pp.510-518
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• 2016

Ethyl cellulose-g-poly(ethylene glycol) (EP) was synthesized by esterification of carboxylic acid functionalized methoxy polyethylene glycol (MPEG-COOH) with ethyl cellulose (EC) in order to develop a hydrophilic substrate for thin-film composite (TFC) membrane in a forward osmosis (FO) system. A porous EP substrate, fabricated by a non-solvent induced phase separation method, was found to be more hydrophilic than the EC substrate due to the presence of polyethylene glycol (PEG) side chains in the EP. Since the EP substrate exhibits smaller water contact angles and higher porosity, the structural parameter (S) of TFC-EP is smaller than that of TFC-EC, indicating that internal concentration polarization (ICP) within porous substrates can occur less when TFC-EP is used as a membrane. For example, the water flux value of the TFC-EP is 15.7 LMH, whereas the water flux value of the TFC-EC is only 6.6 LMH. Therefore, we strongly believe that the TFC-EP could be a promising candidate with good FO performances.

• Journal of Advanced Technology Convergence
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• v.3 no.2
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• pp.25-31
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• 2024

In recent industrialization and development due to information and communication technology, modern women in modern society are exposed to physical and mental health due to numerous stresses. Popular inflammations are attributable to a decrease in lactic acid bacteria, frequent antibiotic use, and a decrease in immunity. It is necessary to develop products that are helpful and reflected. The inner care gel currently introduced on the market can increase beneficial bacteria and maintain a healthy y-zone. The inner gel contains a hydrogel component. 90% is made up of water, and other components act as support for supporting water and are formed through crosslinking between polymer chains. Hydroxyethyl cellulose (HEC) is a hydroxyethyl ethylenetel of cellulose. The purpose of use is to act as a binder, an emulsion stabilizer, a viscosity enhancer (water-soluble), and a film forming agent. CA (crosslinker) is a crosslinking agent and serves to bind. Hydrogel in the beauty field acts as a film forming agent that gently wraps around the skin by forming a thin film and serves as an emulsion stabilizer that helps to prevent separation of other raw materials. It also acts as a thickener by increasing viscosity in cosmetics. In addition, it is used for glucose monitoring, nursing care, cell transplantation, and wound treatment in the bio field. Currently, it is understood that no products using functional hydrogel have been released, so in this study, a Y zone care hydrogel solution was manufactured to find out the antibacterial properties of the functional hydrogel, and a new solution was developed. As a result, it was confirmed that the appropriate Ph was applied to the Y zone, and after culturing Candida albicans in PDB medium, all three products of the Y zone care hydrogel solution showed an antibacterial effect of 0.5-1.0mm

• Journal of the Korean Ceramic Society
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• v.12 no.1
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• pp.5-11
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• 1975

Thick film resistor paste was made utilizing oxide materials such as SnO, SnO＋Sb2O3, and SnO＋Zn. The oxide materials were mixed respectively with Q-12 glass powder and finally suspended in ethyl cellulose dissolved in ethyl cellosolve. Thick film resistor was made by screen printing the paste on the alumina substrate and firing it at a suitable temperature. Among thick films made from the resistor paste, the thick film containing 85% SnO and fired at $600^{\circ}C$ demonstrated the finest electrical properties showing 10 K ohm in sheet resistance, 110 ppm/$^{\circ}C$ in TCR. In general, TCR of the thick films made from the oxide-mixture paste is good in linearity, therefore it is suggested the oxide-mixture paste is utilized as the negative thermistor.

• Applied Chemistry for Engineering
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• v.35 no.3
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• pp.209-213
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• 2024

To improve the adhesion properties between the conductive paste and PET film, the PET film was chemically treated using acids and bases and physically treated through corona discharge. A paste using ethylcellulose, which is used in actual industrial manufacturing and silane-treated CNF, as a binder was manufactured and coated on PET film to compare the adhesive properties. The specimen coated with a paste containing silane-treated CNF as a binder on a corona discharge-treated PET film showed the highest level of adhesion, 5B. On the other hand, it was confirmed that when PET film was chemically treated with acid/base, there was no improvement in adhesive properties.