• Polymer(Korea)
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• v.29 no.1
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• pp.59-63
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• 2005

Kinetic study of a reaction between poly(caprolactone diol) and aliphatic isocyanate was investigated by FTIR spectroscopy. The reaction rate was obtained from analyzing the absorbance change of NCO peak (2265 $cm^{-1}$) in series IR spectra. In the results, the overall reaction between PCL and isocyanate conformed to the simple second-order law, and the rate constant increases with increasing reaction temperature. The activation energies obtained from the evaluation of kinetic data were 25.4∼30.9 kJ/mol for hexamethylene diisocyanate and 16.8∼22.1 kJ/mol for cyclohexylmethane diisocyanate, respectively.

• Polymer(Korea)
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• v.35 no.4
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• pp.296-301
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• 2011

This study focuses on the investigation of the impregnation of poly (vinyl alcohol) (PVA) crosslinked with poly(styrene sulfonic acid-co-maleic acid) (PSSA-MA) to porous polyethylene membrane for the fuel cell application. The membranes were characterized by the measurements of the water content, contact angle, FTIR spectra, thermal gravimetric analysis, ion exchange capacity, proton conductivity, methanol permeability and elastic modulus. The existence of hydrophilic moieties in the impregnated membranes was confirmed by contact angle and FTIR measurements. The impregnated PVA/PSSAMA(90:10) membrane exhibited a higher ion exchange capacity (1.2 meq./g dry membrane) than Nafion membrane (0.91 meq./g dry membrane). Through the elastic modulus measurement, the dimensional stability of the resulting membranes was expected to increase higher than the polyethylene membranes. The methanol crossover and water content decreased even if the PSSA-MA content increased due to the reduction of the free volume.

• ALGAE
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• v.32 no.1
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• pp.75-86
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• 2017

Polysaccharides of marine algae exhibit different structural characteristics and interesting biological functions. In this study, crude polysaccharides (CP) of eleven Sri Lankan marine algae obtained through hot water extraction and ethanol precipitation were investigated for DPPH, alkyl, and hydroxyl radical scavenging activities using electron spin resonance spectrometry and for intracellular reactive oxygen species scavenging activity in the Chang liver cell line. Characterization of CPs was done by Fourier transform infrared (FTIR) spectroscopy and by analysis of the monosaccharide composition. Time-dependent density functional theory quantum-chemical calculations at the RB3LYP/6-31G(d,p) level for constructed dimeric units of the corresponding polysaccharides were used to resolve the FTIR spectra. CPs from Chnoospora minima showed the highest DPPH and alkyl radical scavenging activities and higher intracellular reactive oxygen species scavenging effects for both AAPH and $H_2O_2$ induced ROS production in "Chang" cells. The major polysaccharide constituent in C. minima CP was identified as fucoidan and it displayed a higher sulfate content. The degree of sulfation of these polysaccharides suggests a positive correlation with the observed antioxidant properties.

• 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.

• Analytical Science and Technology
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• v.27 no.6
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• pp.300-307
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• 2014

For the application of chemical assessment standards by the extent of diagenetic alteration, we investigated three archaeological animal bones and a modern animal bone using Fourier transform infrared-attenuated total reflection (FTIR-ATR) spectroscopy and x-ray diffraction (XRD) analysis. The calculating results of crystallinity index (CI), carbonate-to-phosphate (C/P) and carbonate-to-carbonate (C/C) using FTIR-ATR spectra showed differences CI and C/P according to the preservative condition of animal bones. By comparison of the crystallinity contents using XRD patterns, the states of animal bones were distinguished to the range of $30^{\circ}-35^{\circ}$. As results of FTIR-ATR and XRD analysis, it is suggested that Mongolian large mammals bone presents the best preservative condition, and cattle bone from Naju site, and Haman site followed. In addition, those were correlated with the results of histological index. The results suggested that the chemical assessment standards may contribute to application of predictions of the states of animal bones discovered from Korea.

• Macromolecular Research
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• v.15 no.6
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• pp.575-580
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• 2007

Water-soluble, chiral conducting, poly(diphenylamine) (PDPA) nanocomposites were synthesized by chemical oxidative polymerization of diphenylamine in the presence of poly(acrylic acid) (PAA) as a template and camphor sulphonic acid (CSA) as the chiral inductor, Composites were formed as stable aqueous dispersions under different experimental conditions, such as DPA to PAA molar ratios, PAA molecular weight, etc. Circular dichroism(CD) spectra of the composites indicated the induction of chirality to PDPA. Compared to simple chiral PANI, the PDPA/PAA/CSA nanocomposites showed a different Cotton effect. The appearance of a CD band in the composite was complimentary to the bisignate, exciton-coupled band in the UV-Visible spectrum. FTIR spectra indicated the intimate mixing of PDPA and PAA.

• Fashion & Textile Research Journal
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• v.10 no.1
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• pp.101-105
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• 2008

This study was concerned with the influence of reaction conditions on the surface friction properties of Syrene-Butadiene Rubber(SBR) sheet when it was chlorinated by chemical treatment method using the sodium hypochlorite and sulfuric acid. The results of this study were as follows. SEM photographs of chlorinated SBR surface showed uneven etching caused by the chlorination. In the FTIR spectra, the intensity of C=C peak of SBR was decreased with increasing the concentration of sodium hypochlorite. Otherwise there was no trace of C=C peak in spectrum of SBR treated with 5 wt% NaOCl with pH 0.1 for 90 seconds. EDX spectra showed that relative content of chlorine of SBR was increased with increasing the amount of sodium hypochlorite, and also affected with pH condition of acid solution. Friction angle and friction coefficient of SBR were influenced with concentration of sodium hypochlorite, but were not with pH condition of acid solution.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.04a
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• pp.88-91
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• 2003

Si nanocrystallites thin films have been fabricated by pulsed laser deposition using a Nd:YAG laser. After deposition, samples were annealed at the temperature range of 400 to $800^{\circ}C$. Hydrogen passivation was then performed in the forming gas ($95%N_{2}+5%H_{2}$) at $500^{\circ}C$. Strong violet-indigo photoluminescence has been observed at room temperature on nitrogen ambient-annealed Si nanocrystallites. As a result of photoluminescence spectra and infrared absorption spectra, we conclude that the violet-indigo PL efficiency is related with oxygen vacancy in the $SiO_x$(x= 1.6-1.8) matrix.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2002.11a
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• pp.34-46
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• 2002

Si-O-C-H films with a low dielectric constant were deposited on a p-type Si(100) substrate using a mixture gases of the bis-trimethylsilyl-methane (BTMSM) and oxygen by an inductively coupled plasma chemical vapor deposition (ICPCYD). High density plasma of about $~10^{12}\textrm{cm}^{-3}$ is obtained at low pressure (<400 mTorr) with rf power of about 300W in ICPCVD where the BTMSM and $O_2$ gases are fully dissociated. Fourier transform infrared (FTIR) spectra and X-ray photoelectron spectroscopy (XPS) spectra show that the film has $Si-CH_3$ and OH-related bonds. The void within films is formed due to $Si-CH_3$ and OH-related bonds after annealing at $500^{\circ}C$ for the as-deposition samples. The lowest relative dielectric constant of annealed film at $500^{\circ}C$ is about 2.1.

• Korean Journal of Materials Research
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• v.16 no.12
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• pp.771-776
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• 2006

In this study, we report a method to synthesize the aluminum nitride (AlN) powders from aluminum oxyhydroxide (AlOOH). AlOOH powders were prepared from the aluminum hydroxide ($Al(OH)_3$) by heattreatment at the reaction temperature of $350^{\circ}C$. Simple heat treatment of AlOOH in the flow of $NH_3$ gas leads to the formation of hexagonal AlN powders through intermediate conversion of ${\delta}-,\;{\gamma}-$ and ${\alpha}-Al_2O_3$. The FTIR transmission spectra show a broad peak related to Al-N bonds centered around 690 $cm^{-1}$ confirming the presence of AlN. The major peaks in Raman spectra were observed in 250 $cm^{-1}$ and 659 $cm^{-1}$. From the results, synthesized powders from the AlOOH powders were confirmed AlN powders.