• Composites Research
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• v.26 no.1
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• pp.48-53
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• 2013

This paper summarizes the structural characterization of borassus fruit fibers by means of various characterization techniques, optimization of alkali treatment of borassus fruit fine fibers (BFF) with a 5% concentration sodium hydroxide solution for different time intervals (1, 4, 8 and 12 h) and the changes occurring in borassus fibers. This paper also discusses the manufacturing of BFF/PP compotes using MAPP as a compatibilizer in addition to alkali treatment. Composites were evaluated for their mechanical and morphological properties. The tensile strength and modulus, flexural strength and modulus and impact strength were increased for alkali treated/MAPP composites by 4.5%, 17%, 17.2 %, 9% and 10% respectively.

• Journal of the Korean Applied Science and Technology
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• v.10 no.2
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• pp.29-33
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• 1993

n-Octyldimethylbenzylammonium chloride, dodecyldimethylbenzylammonium chloride, and octadecyldimethylbenzylammonium chloride were synthesized to be used as the accelerating weight loss agent. These synthesized compounds were used for the weight loss treatment of PET textile with sodium hydroxide. From the treatments, it was found that the lower carbon number of high alkyl group existed in quaternary ammonium salts, the better effect of weight loss was acquired. The proper concentration of accelerating weight loss agent was $8{\sim}10g/l$, the proper treatment time was $60{\sim}90$ minutes, the proper treating bath ratio was 1 : 50. It is proved that n-octyldimethylbenzylammonium chloride and dodecyldimethylbenzylammonium chloride are good accelerating weight loss agent.

• Membrane and Water Treatment
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• v.8 no.2
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• pp.149-160
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• 2017

This study investigated effects of NaOH cleaning on the intrinsic permeability of polyvinylidene fluoride (PVDF) membranes and flux recoveries and membrane resistances under various conditions encountered during ultrafiltration in water treatment plants. The NaOH cleaning using 10,000 mg/L NaOH led to discoloration of PVDF membranes and had little effect on water flux. The NaOH cleaning was efficient in removing the fouling layer caused by humic water. However, long filtration induced a fouling layer that was not removed easily by NaOH cleaning. The lower temperature during filtration yielded rapid increases in transmembrane pressure and decreases in NaOH cleaning efficiency. The alkaline cleaning of PVDF changed the membrane properties such as the hydrophobicity and morphology. Foulant properties, operational conditions such as temperature, and chemical agents should be considered for cleaning strategies for PVDF applied in water treatment.

• Journal of the Korean Society of Clothing and Textiles
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• v.29 no.7 s.144
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• pp.938-947
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• 2005

Kenaf basts were double retted by using water and enzyme. The best conditions were enzyme concentration $0.125\%$ and 1 day treatment at $50^{\circ}C$, 4 days treatment at $20^{\circ}C$. It was showed that the double rotting could be more economical and eco-friendly than just water rotting or enzyme rotting. Kenaf fibers have been cottonized by removing lignin and hemicellulose partially. In order to cottonize kenaf fiber, lignin of kenaf fibers were removed by sodium chlorite and then hemicellulose of kenaf fibers were removed by sodium hydroxide. The cottonizing phenomenon of kenaf fibers were was confirmed in transversal and longitudinal photograph of SEM. The tensile strength and crystallinity of cottonized fiber were investigated. The tensile strength and crystallinity were lower as the lignin and hemicellulose of kenaf fibers were less.

• Textile Coloration and Finishing
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• v.30 no.1
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• pp.29-37
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• 2018

Cotton has no adsorption ability for the cationic dye and heavy metal but, if anionized cotton can be made, it will be possible. In this study, to enable the anionisation of cotton fabric, it was modified using sodium vinylsolfonate(SV) as the anionisation reagent, employing a pad-dry-cure(PDC) technique. The effects of curing time, treatment concentrations of urea, sodium hydroxide and SV on the weight increase were experimented and then, the physical characterizations of sulfoethyl cotton(SEC) depending on the finishing conditions were estimated, thus the application possibility of SV as anionisation reagent was investigated. It was not much changed by anionisation except wrinkle recovery. And the structure of SEC was elucidated by Raman and NMR spectoscopy. The feasibility of using Raman and NMR spectroscopy with the band at $1,043cm^{-1}$, and 50.5ppm, respectively as marker band to determine sulfoethyl group of SEC was reported. The total degree of SV substitution(DSV) was determined via elemental analysis. SEC with diverse total DSV up to 0.066 was obtained. In the thermal decomposition(pyrolysis) by DSC, it can be found that the pyrolysis temperature was about $30^{\circ}C$ lower than that of non-treated cotton fabric.

• Journal of Life Science
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• v.12 no.6
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• pp.694-699
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• 2002

The present experiment was carried out to determine the effect of seed-coat softening by various chemicals, washing, chilling, and light treatment alone and in combination during desiccation of seeds on germination of gourd (Lagenaria siceraria Standl.) seeds. Potassium hydroxide, sodium hydroxide, acetone, acetonitrile, and acetamide were used as chemicals for the softening. Washing, prechilling, drying and light treatment of the softened seeds were done for a hour with tap water, for one or three weeks at 3$^{\circ}C$, 12 hr at 35$^{\circ}C$, and 14 hr a day at 3$0^{\circ}C$ with red light illumination or darkness, respectively. FR-yongjadaemok and FR-kunghap were used as test cultivars. Seed-coat softening with 10% acetone and acetonitrile for 1 hour enhanced and accelerated seed germination compared to the other chemicals and water imbibition. KOH treated for the softening was necessary to increase the germination rate of seeds for following chilling, but acetone did not influence their germinability regardless of chilling. Washing the softened seeds in tap water increased the germination rate in comparison with no-washing. During desiccation of the seeds sequentially treated with the softening, washing and chilling, red light treatment showed higher germination rate than dark one, suggesting that red light treatment are necessary during desiccation.

• Restorative Dentistry and Endodontics
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• v.40 no.2
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• pp.104-112
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• 2015

Objectives: This study was performed to investigate the effects of different intracanal medicaments on chemical structure and microhardness of dentin. Materials and Methods: Fifty human dentin discs were obtained from intact third molars and randomly assigned into two control groups and three treatment groups. The first control group received no treatment. The second control group (no medicament group) was irrigated with sodium hypochlorite (NaOCl), stored in humid environment for four weeks and then irrigated with ethylenediaminetetraacetic acid (EDTA). The three treatment groups were irrigated with NaOCl, treated for four weeks with either 1 g/mL triple antibiotic paste (TAP), 1 mg/mL methylcellulose-based triple antibiotic paste (DTAP), or calcium hydroxide [$Ca(OH)_2$] and finally irrigated with EDTA. After treatment, one half of each dentin disc was subjected to Vickers microhardness (n = 10 per group) and the other half was used to evaluate the chemical structure (phosphate/amide I ratio) of treated dentin utilizing attenuated total reflection Fourier transform infrared spectroscopy (n = 5 per group). One-way ANOVA followed by Fisher's least significant difference were used for statistical analyses. Results: Dentin discs treated with different intracanal medicaments and those treated with NaOCl + EDTA showed significant reduction in microhardness (p < 0.0001) and phosphate/amide I ratio (p < 0.05) compared to no treatment control dentin. Furthermore, dentin discs treated with TAP had significantly lower microhardness (p < 0.0001) and phosphate/amide I ratio (p < 0.0001) compared to all other groups. Conclusions: The use of DTAP or $Ca(OH)_2$ medicaments during endodontic regeneration may cause significantly less microhardness reduction and superficial demineralization of dentin compared to the use of TAP.

• Fashion & Textile Research Journal
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• v.13 no.6
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• pp.972-982
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• 2011

The purpose of this study is to improve the method of color developing with alkali solution as a promotor of color developing for feasible use. Cotton fabric was dyed with persimmon extract ranged with 0~3% alkali component with 5 types of strong to mild alkali solution. Heat treatment for color developing was applied to fabric dyed with persimmon extract and alkali mixing solution. Tests were carried out to analyze the change of surface color, ${\Delta},Ea^*b^*$, and water repellent of the dyed cotton fabric. The alkali mixing sample showed higher ${\Delta},Ea^*b^*$ value than control one without alkali mixing on the base of dyed fabric due to high color developing by alkali in the initial step of dyeing process. As alkali concentration increased, deeper dark color appeared on the fabric. The fabric color was changed to more dark in the application of sodium hydroxide, sodium carbonate, potassium carbonate in the initial step of dyeing process but color was not changed by increased heating time. However, the fabric showed a slight dark color with sodium acetate and more color change than that of the fabric dyed with persimmon extract without alkali. Therefore, sodium acetate seemed to a suitable promotor for color developing in persimmon extract dyeing. Property of water repellent was showed after color developing by heating with low concentration of alkali treatment.

• Textile Coloration and Finishing
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• v.4 no.3
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• pp.131-135
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• 1992

Quaternary aminized cellulosic adsorbents (C $A_{QA}$ ) which exhibit adsorption capacities for anionic dyestuffs for the treatment of colored waste water and re-use of the treated water were studied. The isotherms and thermodynamic parameters of C.I. Acid Orange 7, solution considered as a model of negatively charged coloring matters for C $A_{QA}$ , were determined. Batch method and flow method were employed to determine decoloring capacity of cellulosic adsorbents for Orange 7. The cellulosic adsorbents exhibited much better adsorption capacity than activated carbon. Furthermore the exhausted cellulosic adsorbents could be readily regenerated by washing with dilute sodium hydroxide.

• Environmental Analysis Health and Toxicology
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• v.29
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• pp.7.1-7.8
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• 2014

Objectives The present study was designed to systematically characterize the denaturation and the renaturation of double stranded DNA (dsDNA), which is suitable for DNA hybridization. Methods A series of physical and chemical denaturation methods were implemented on well-defined 86-bp dsDNA fragment. The degree of each denaturation was measured and the most suitable denaturation method was determined. DNA renaturation tendency was also investigated for the suggested denaturation method. Results Heating, beads mill, and sonication bath did not show any denaturation for 30 minutes. However probe sonication fully denatured DNA in 5 minutes. 1 mol/L sodium hydroxide (alkaline treatment) and 60% dimethyl sulfoxide (DMSO) treatment fully denatured DNA in 2-5 minutes. Conclusions Among all the physical methods applied, the direct probe sonication was the most effective way to denature the DNA fragments. Among chemical methods, 60% DMSO was the most adequate denaturation method since it does not cause full renaturation during DNA hybridization.