• Microbiology and Biotechnology Letters
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• v.52 no.2
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• pp.189-194
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• 2024

Plastics are consistently produced owing to their practicality and convenience. Unmanaged plastics enter the oceans, where they adversely impact marine life, and their degradation into nano-plastics due to sunlight and weathering is of concern for all living beings. Nano-plastics affect humans via the food chain, emphasizing the necessity for effective solutions. Microbial biodegradation has been suggested as a solution, offering the advantages of minimal environmental impact and the utilization of decomposition byproducts in microbial metabolic pathways. In this study, fifty-seven bacterial strains were isolated and identified from a waste-treatment facility. Cultivation in a minimum medium with low-density polyethylene (LDPE) beads as the sole carbon source resulted in the selection of the LDPE-degrading strain Acinetobacter guillouiae PL211. The selected strain was cultured at high cell density with LDPE as a carbon source, and Fourier transform infrared (FT-IR) analysis confirmed chemical changes on the LDPE bead's surface. Field-emission scanning electron microscopy (FE-SEM) analysis revealed substantial biodegradation of the LDPE surface. These results demonstrated the capability of A. guillouiae PL211 to biodegrade LDPE beads. This discovery demonstrates the potential of an environmentally friendly process to addressing polyethylene waste issues.

• Analytical Science and Technology
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• v.27 no.1
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• pp.27-33
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• 2014

This study described about preparation of the cross-linked silk fibroin (SF) film by ${\gamma}$-irradiation of the casted SF film, which is fabricated from aqueous solution regenerated via fibers of cocoons and their application as supports for human cell culture. The properties of cross-linked SF film were evaluated by FT-IR spectroscopy, contact angle, solubility to water, thermal analysis, surface area analyzer, and morphology via scanning electron microscopy (SEM). The cross-linked SF films were not dissolved in water and exhibited the rough surface morphology, large surface area, and good thermal properties. The human fibroblast cell (CCD-986sk) and embryo kidney-ft cell were well growed on the surface of cross-linked SF film supports prepared by ${\gamma}$-irradiation. The cross-linked SF film prepared by ${\gamma}$-irradiation can be used as biomaterials for human cell culture.

• Journal of Sericultural and Entomological Science
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• v.49 no.1
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• pp.8-13
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• 2007

Natural indigo colorants were prepared by extraction of Polygonum tinctorium which was harvested just in the blooming season(in the late of July). The components were analyzed by TLC and HPLC, and its structures were analyzed by FT-IR, EI-mass. The results obtained are summarized as follows; The natural indigo powder was dissolved in DMSO and developed in eluent, $CHCI_3/CH_3CN$(8.5:1.5 v/v) by means of TLC for its quality analysis. It was segregated into indirubin as a red colour and indigo as a blue colour. In case of HPLC analysis,. FT-IR spectrum of indirubin showed a peak for NH residue between 3200 and $3300cm^{-1}$. $^1H-NMR$ spectrum for indigo displayed AA'BB' spin system caused by indole structure between 6.5 and 7.7ppm of H4, 5, 6 and 7, and -NH proton for indirubin showed an singlet between 10.88 and 11.0ppm. EI-mass spectrum of indigo and indirubin both disclosed their molecular size as 262 and it implies that these two substances are isomer.

• Journal of the Korean Society of Costume
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• v.58 no.5
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• pp.211-231
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• 2008

To conserve historic textiles, analyses of textile materials, pollutants and deterioration are prerequisite steps. Based upon analytical results, guides for conservation of historic textiles are established. In analyses of textile materials, pollutants and deterioration, there are chemical methods(burning, solubility and staining), physical methods(microscopy and density) and instrumental analysis(Fourier Transform Infrared Spectroscopy (FT-IR), Fourier Transform Raman Spectroscopy(FT-Raman), Gas Chromatography(GC), Mass Spectroscopy(MS), X-Ray Fluorescence (EDXRF, WDXRF), Energy Dispersive Spectroscopy(EDS), and X-Ray Diffraction(XRD), Tensile Testing Machine etc.). Combination of qualitative and quantitative analyses makes accurate diagnosis of textile condition possible. As examples of analyses and conservation of historic textiles, Chuninsan(19 century) similar to sunshade with handing down historic textile and golden decorative skirt(17 century) with excavated costume are taken.

• Journal of the Mineralogical Society of Korea
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• v.18 no.4 s.46
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• pp.313-323
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• 2005

XRD, XRF, EPMA, FT-IR, and SEM-CL studies were carried out in order to characterize gemological features of corundum from Tanzania. Fluorescence reaction of the Tanzanian corundum to short and long wave ultraviolet rays was weakly detected. Inclusions in Tanzanian corundum are divided into five types, Type I is fluid-rich inclusion, Type II is gas-rich inclusion, Type III is liquid $CO_{2}$ inclusion, Type IV is solid-rich inclusion, and Type V is a mixture of fluid and solid inclusion and daughter minerals. SEM-CL images show twin structure with growth texture, microphenocryst of spinel solid inclusions, massive and growth texture. Ruby and sapphire from Tanzania are distinctly distinguished by concentrations of Fe and Cr, and plotted in the particular field at $Al_{2}O_{3}/100-Cr_{2}O_{3}-Fe_{2}O_{3}$ diagram. According to FT-IR analysis, all corundum specimens from Tanzania showed the similar patterns, and absorption peaks of $455.09\~459.23\;cm^{-1},\;603.15\~611.71\;cm^{-1},\;1509.00\~1655.05\;cm^{-1}\;and\;3436.41\~3468.87\;cm^{-1}$. These distinctive characteristics mentioned above can be used to identify the locality and source of corundum stones from Tanzania.

• Journal of the Korean Chemical Society
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• v.47 no.2
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• pp.147-154
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• 2003

In this study, the fluorinated carbon blacks(CB) were used to reduce the negative temperature coefficient (NTC) phenomenon of the CB-filled high density polyethylene(HDPE) compounds in the fluorination pressure of 0.1-0.4 MPa. The changes in surface properties of the CB were investigated by using FT-IR, XPS and contact angle measurements. From the FT-IR results, the fluorinated CB showed the C-F absorption peak at 1400-1000 cm$^{-1}$ and the peak intensity was increased with increasing the fluorination pressure. Also, the analysis of XPS spectra of the fluorinated CB indicated that fluorine content was increased with increasing the fluorination pressure. Meanwhile, the surface free energy of the fluorinated CB was decreased with increasing the fluorination pressure. Consequently, the increase of fluorine contents on CB made a disappearance of NTC behaviors of CB/HDPE compounds, which was probably due to the reduction of CB reaggregation after melting point of the HDPE, resulting from decreasing the surface free energy of CB particles.

• Journal of Adhesion and Interface
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• v.2 no.2
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• pp.1-10
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• 2001

Silica for Epoxy Molding Compound (EMC) was coated via plasma-polymerization with RF plasma (13.56 MHz) as a function of treatment time, power and pressure. 1,3-diaminopropane, allylamine, pyrrole, 1,2-epoxy-5-hexene, allylmercaptan or allylalcohol were utilized for plasma polymerization coating and adhesion of coated silica was evaluated by measuring flexural strength. CTE and water absorption of EMC were also measured, and fracture surface of flexural specimen was analyzed by SEM in order to elucidate the failure mode. The plasma polymer coated silica was analyzed by FT-IR and reactivity of plasma polymer coating with epoxy resin was evaluated with DSC in order to investigate the adhesion mechanism. The EMC prepared from the silica coated with 1,3-diaminopropane or allylamine exhibited high flexural strength, low CTE, and low water absorption compared with the control sample, and also exhibited 100% cohesive failure mode. These results can be attributed to the chemical reaction between the functional groups in the plasma polymer coating and epoxy resin, and also consistent with the results from FT-IR and DSC analysis.

• Korean Journal of Materials Research
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• v.4 no.5
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• pp.550-555
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• 1994

The effects of RTA treatment on the leakage current have been studied for tantalum pentoxide( $Ta_2O_5$) films deposited by PECVD on P-type(100) Si substrate using $TaCl_5$(99.99%) and $N_2O$(99.99%) gaseous mixture. The refractive index increased with increasing the deposition temperature and the maximum deposition rate was obtained at $500^{\circ}C$. The Ta-0 bond peak intensity of as-deposited $Ta_2O_5$ increased with increasing the deposition temperature through FT-IR analysis and the leakage current value was decreased with increasing the deposition temperature. The small leakage current value obtained after RTA treatment of as-deposited $Ta_2O_5$ was found to be due to the reduction of 0-deficient structure in the film. The increases of the oxygen coacentration and the Ta-0 bond peak intensity in the film after RTA treatment were measured by AES and FT-IR analyses.

• Applied Chemistry for Engineering
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• v.22 no.4
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• pp.353-357
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• 2011

For the purpose of introducing hydrophilic function to pristine PVDF, pristine PVDF was modified under atmosphere and aqueous vapor by irradiating electron beam (EB). EB dose was varied from 0 to 125 K Gray, respectively. Their changes of chemical composition /structure were observed and evaluated by FT-IR, EDS and DSC. Also, their surface behaviors were evaluated by contact angle. In FT-IR study, it was confirmed that hydroxyl functions were introduced to pristine PVDF. In EDS analysis, mole ratio of F (fluoride) was almost constant (about 33%) in spite of increasing EB dose, meaning that hydroxyl function was introduced via dehydrozenation, not via deflurodination. In DSC study, $T_g$ increased with increasing EB dose, which was reconfirmed that hydroxyl function was introduced via dehydrozenation. $T_m$ increased with increasing EB dose, inferring that the increase in EB dose led to more outbreak of hydroxyl function which led to more enhanced hydrogen bond. In the result of contact angle, pristine PVDF film was $62^{\circ}$ and 125 K Gray-irradiated PVDF film was even $13^{\circ}$. All results showed that pristine PVDF was successfully changed to hydrophilic PVDF.

• Clean Technology
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• v.16 no.3
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• pp.191-197
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• 2010

Repair reaction of plasma damaged porous methyl doped SiOCH films was carried out with silylation agents dissolved in supercritical carbon dioxide ($scCO_2$) at various reaction time, pressure, and temperature. While a decrease in the characteristic bands at $3150{\sim}3560cm^{-1}$ was detectable, the difference of methyl peaks was not identified apparently in the FT-IR spectra. The surface hydrophobicity was rapidly recovered by the silylation. In order to induce effective repair in bulk phase, the wafer was heat treated before reaction under vacuum or ambient condition. The contact angle was slightly increased after the treatment and completely recovered after the subsequent silylation. Methyl groups were decreased after the plasma damage, but their recovery was not identified apparently from the FT-IR, spectroscopic ellipsometry, and secondary ion mass spectroscopy analyses. Furthermore, Ti evaporator was performed in a vacuum chamber to evaluate the pore sealing effect. The GDS analysis revealed that the open pores in the plasma damaged films were efficiently sealed with the silylation in $scCO_2$.