• Journal of the Korean Home Economics Association
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• v.25 no.4
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• pp.9-18
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• 1987

This study is conducted to investigate the influence of addition of quarternary ammonium salt(cetyl trimethyl ammonium bromide: CTAB) when polyester(PET) fabric is treated with sodium hydroxide(NaOH), depending on experimental variables such as CTAB concentration, NaOH concentration, time & temperature, and the change in physical & chemical properties of alkaline-hydrolyzed PET fabrics depending on their weight loss. The results are as follows: 1. By adding CTAB in aqueous NaOH, the weight loss of PET fabric is increased remarkably and until the concentration of CTAB is reached at its cmc, and the higher the concentration of CTAB are, the more weight loss on PET fibrics are. 2. The addition of CTAB in aqueous NaOH is most effective at lower NaON concentration(2%) among various NaOH concentration, on increasing the amount of weight loss, while there are almost similar results through various treatment time and temperature. 3. As the amount of weight of weight loss on PET fabric is increased, the increase of void space in the PET yarn, of softness & dyeability of PET fabric and the decrease of tensile strength are found. On the other hand, the moisture regain shows a little increase by alkaline-hydrolysis on PET fabric while vertical absorption test & water retention value are not sufficiently sensitive to distinguish between the hydrophillicity of untreated and treated PET fabric. The shrinkage of PET fabric is induced by swelling in hot aqueous NaOH regardless of NaOH concentration & addition of CTAB.

• Elastomers and Composites
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• v.42 no.2
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• pp.75-85
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• 2007

In this study, the new adhesion system was studied to improve the adhesion strength between polyester cord and rubber matrix. In order to enhance the adhesion strength through polyester cord's surface treatment, the NaOH solution was used. The NaOH solution concentrations of 0.03, 0.05, 0.1, 0.2, 0.5, 1 and 5 wt.% were used in surface modifying the polyester cord. The optimum condition showing the maximum adhesion strength of polyester cord with SBR compound containing bonding agent was at NaOH concentration of 0.05 wt.% with treatment time of 10 minutes. When the NaOH solution concentration was above 1 wt.%, the polyester cord due to the excess surface modification was damaged, and resulted in breakage during the adhesion test. Also, the adhesion strength between polyester and SBR could be improved by coating the polyester cord with triallylcyanurate(TC) adhesive. The drying condition of polyester cord coated with TC attributed to the adhesion strength. The maximum adhesion strength was obtained by using the polyester cord dried at $220^{\circ}C$ rather than dried at room temperature.

• Animal Bioscience
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• v.35 no.7
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• pp.1048-1058
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• 2022

Objective: The present study was to investigate the extraction conditions of dietary fiber from dried cassava pulp (DCP) and cassava distiller's dried grains (CDG) under different NaOH concentrations, and the Fourier transform infrared (FTIR) was used to determine the dietary fiber components. Methods: The dried samples (DCP and CDG) were treated with various concentrations of NaOH at levels of 2%, 4%, 6%, and 8% using a completely randomized design with 4 replications of each. After extraction, the residual DCP and CDG dietary fiber were dried in a hot air oven at 55℃ to 60℃. Finally, the oven dried extracted dietary fiber was powdered to a particle size of 1 mm. Both extracted dietary fibers were analyzed for their chemical composition and determined by FTIR. Results: The DCP and CDG treated with NaOH linearly or quadratically or cubically (p<0.05) increased the total dietary fiber (TDF) and insoluble fiber (IDF). The optimal conditions for extracting dietary fiber from DCP and CDG were under treatment with 6% and 4% NaOH, respectively, as these conditions yielded the highest TDF and IDF contents. These results were associated with the FTIR spectra integration for a semi-quantitative analysis, which obtained the highest cellulose content in dietary fiber extracted from DCP and CDG with 6% and 4% NaOH solution, respectively. The principal component analysis illustrated clear separation of spectral distribution in cassava pulp extracted dietary fiber (DFCP) and cassava distiller's dried grains extracted dietary fiber (DFCDG) when treated with 6% and 4% NaOH, respectively. Conclusion: The optimal conditions for the extraction of dietary fiber from DCP and CDG were treatment with 6% and 4% NaOH solution, respectively. In addition, FTIR spectroscopy proved itself to be a powerful tool for fiber identification.

• Journal of the Korean Chemical Society
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• v.16 no.4
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• pp.241-248
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• 1972

The adsorption of Methylene Blue on Yeong-Il bentonite which was treated by aqueous NaOH, $Na_2SO_4 or NaHSO_4 solution respectively, varying concentrations, temperature and time, was studied. In case of treatment with NaHSO_4 solution, slight improvement of the adsorption of Methylene Blue on bentonite was observed. With Na_2SO_4$ solution, the best results obtained when bentonite was treated with 1 N of the solution for 2hr at $100^{\circ}C$, and the adsorption capacity of the product was 3 times better than that of original bentonite. At the higher concentration and the higher temperature than above, faujasite was formed. With NaOH solution, the best condition was in 1N solution for 1hr at $100^{\circ}C$ and the adsorption capacity of the product was 3.3 times better than that of original bentonite. At the higher concentration of the treating agent and at the higher temperature than above, hydroxysodalite was formed.

• The Korean Journal of Mycology
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• v.39 no.3
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• pp.235-238
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• 2011

Agrobacterium harboring vector pCHBs with hygromycin phosphotransferase(hph) and hepatitis B virus surface antigen(HBsAg)gene was transformed into the mycelial culture of Flammulina velutipes. In particular, mild NaOH solution was treated to the mycelia before Agrobacterium infection step. This was purposed to generate putative surface wounds in the mycelial cell walls. The results showed that hygromycin-resistant($hyg^r$) mycelia could be obtained only from NaOH-treated mycelia but not from intact mycelia. The integration of $hyg^r$ gene in fungal genome was confirmed by PCR. In addition, a single transgene integration and heterologous protein expression in F. velutipes could be verified by Southern blot hybridization and western blot analysis, respectively. This study demonstrated an efficient tool for the Agrobacterium-mediated transformation of F. velutipes mycelia.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.35 no.4
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• pp.1-7
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• 2003

In this study, fiber mechanical pretreatment before refining was executed with the addition of papermaking addiditives to find synergistic effects on fiber property improvement. Three fiber furnishes (SwBKP, KOCC, and BCTMP), and five different additives (CMC, CPAM, PEO, NaOH, $Na_2O_2$) were used. It was confirmed again that fiber mechanical pretreatment using Hobart mixer was a special way to modify fiber properties, where fiber WRV (water retention value) increases without losing fiber length. For SwBKP, addition of small amount of CMC (0.2％ OD basis), and for KOCC, PEO (0.2％ OD basis) caused additional significant improvement of the fiber furnish properties, respectively. Other additives did not cause adverse effects on the mechanical pretreatment, or better. For BCTMP, NaOH addition followed by mechanical pretreatment caused more than 20％ improvement in tensile and tear strength simultaneously, compared to the control. The yellowing caused by the treatment of NaOH on BCTMP could be minimized by using $Na_2O_2$ without losing the positive effect of NaOH.

• Microbiology and Biotechnology Letters
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• v.2 no.2
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• pp.79-82
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• 1974

Present experiments were designed to estimate the effects of pretreatments by various kinds of alkalis to the agricultural wastes such as cereal straws as the substrate on the production of cellulosic single-cell protein. Among the various kinds of alkalis NaOH was proved to be the most effective on improving the digestibility of cellulose by the bacteria isolated. NH$_4$OH which is inferior to NaOH in the effectiveness of treatment might have more economic advantage in the price, and the ammonium salt resulted from the neutralization can be used as the nitrogen source by bacteria. The treatment with higher concentration than 1 normality of NH$_4$OH didn't increase the productivility of cell mass. About five per cent of (NH$_4$)$_2$SO$_4$ in medium resulted from the neutralization didn't have any influence in the cell mass productivility. Futhermore, the cell mass productibility was higher in the case of neutralization than alkali free washing. The digestibility of straws was increased from 7.9％ to 46.0％ by NH$_4$OH treatment, and 6.3∼6.45g of dry cell were obtained from 40g of NH$_4$OH treated straws. In the case of NaOH treatment, 8.6g of cell mass was obtained from 40g of substrate.

• Journal of the Korean Society of Food Science and Nutrition
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• v.17 no.2
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• pp.85-94
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• 1988

This experiment was carried out to obtain the basic data for removal the astringency and off-flavor in soybean milk, by means of soaking of soybean in NaOH and $NaHCO_3$ solutions. The changes of phenolic compounds in soybean during soaking were investigated with HPLC and also the changes of flavor and sensority of soybean milk, prepared from soaked soybean were studied. Phenolic compounds of soybean were identified as chlorogenic, p-hydroxybenzoic, p-coumaric, ferulic and gentisic acid and, chlorogenic acid content was greater than the others. The chlorogenic acid of soybean was mainly neutral type and the other compounds were almost acidic type. Up to 85% of the chlorogenic acid was removed by soaking of soybean in 0.1% of NaOH solution for 8 hrs. Phenolic compounds of soybean was almost removed by soaking in 0.1% of NaOH solution at $90^{\circ}C$ for 1 hr. Chemical composition of soybean milks prepared from soaking of soybean in water, 0.1% NaOH and 0.5% $NaHCO_3$ solution were similar. Hexanol content of beany flavor in soybean milk was increased by soaking of soybean in NaOH solution, where as hexanal, propanal, pentanal contents were removed up to 60%. Color of soybean prepared from soaking of soybean in NaOH solution at high temperature were deep yellow but were high whiteness in soybean milk prepared from soaking of soybean in water at low temperature. Sensority of soybean milk prepared from soaking of soybean in 0.1% of NaOH solution at $90^{\circ}C$ for 1 hr was more favorable than the others.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.8
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• pp.930-937
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• 2007

Korean pine(Pinus densiflora) bark was evaluated for its adsorption capacity of Cu(II) ions from aqueous solution by running a series of batch experiments. Prior to the tests, the milled barks were treated with 1 N NaOH or 1 N HCl to examine the effect of surface modification. For comparison, untreated bark was tested under same condition. Within the tested pH range between 3 and 6, NaOH treatment increased Cu(II) adsorption capacity by $139\sim184%$, while HCl treatment decreased it by $37\sim42%$. Maximum copper ion uptake by bark was observed at pH $5\sim6$, but pH of solution was not a potent influence. A pseudo second-order kinetic model fitted well for the sorption of copper ion onto bark. For NaOH-treated bark, the calculated sorption capacity$(q_e)$ increased from 6.58 to 12.77 mg/g, while the equilibrium rate constant$(k_2)$ decreased from 0.284 to 0.014 g/mg/min as initial Cu(II) concentration doubled from 100 mg/L. A batch isotherm test using NaOH-treated bark showed that equilibrium sorption data were represented by both the Langmuir model and the Freundlich model. It was confirmed that carboxylic acid of bark was involved in the Cu(II) adsorption. For NaOH-treated bark, in particular, carboxylate ion produced by hydrolysis or saponification appeared to be a major functional roup responsible for the enhanced Cu(II) sorption.

• Resources Recycling
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• v.19 no.1
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• pp.40-48
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• 2010

It was investigated that effects of NaOH concentration on synthesis of mesoporous materials using municipal solid waste incinerator ash slag (MSWI-ash slag). In order to increase the purity and maximize the amount of extracted Si content the raw MSWI-ash slag was mechanically activated. Extraction of Si from the MSWI-ash slag was carried out by alkali treatment using concentrated NaOH solution, which varied from 1M to 4M. Physical properties (i.e., pore size, specific surface area and total pore volume) of the synthesized mesoporous silica were also evaluated as a function of NaOH concentration via BET, SEM, TEM and small-angle X-ray scattering analyses. Over the entire range of NaOH concentration investigated (i.e., 1-4M), the synthesized mesoporous materials were determined to be SBA-15, which exhibited a hexagonal structure with the pore size of approximately 7 nm. On the other hand, specific surface area and total pore volume increased with NaOH concentration up to 3M while the values decreased at 4M, indicating that the optimal NaOH concentration for the synthesized mesoporous silica was approximately 3M. Further comparison analysis between two conditions (3M versus 4M) showed that the decrease in two physical properties at 4M NaOH concentration was likely due to the potential inhibition by excess Na ions on the formation of mesophase and the consequent increase of pore wall thickness by remaining Si ions.