• Proceedings of the Korean Vacuum Society Conference
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• 1999.07a
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• pp.203-203
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• 1999

Mass spectrometry technique provides the molecular weight distribution, data on the sequence of repeat units, polymer additives, and impurities, and structural information. time-of-Flight secondary Ion Mass Spectrometry (TOF-SIMS) has been used for structural characterization of various polymers1-2. the masses of repeat units and terminal groups and molecular weight distributions of polymers have been determined from their TOF-SIMS spectra. TOF-SMIS provides good sensitivity and structural specificity for high mass ions so that intact oligomers and large polymer fragments are observed. In this study, we investigated the detailed structural information on the oligomers and fragment ions of branched poly(1,3-butylene adipate) and branched poly[di(ethylene glycol) adipate] and the transesterification products of branched polyesters with trifluoroacetic acid or chloro difluoroacetic acid. Branched polyesters were chosen because they are important polymers but difficult to characterize; thus branched polyesters provide challanging test for TOF-SIMS. TOF-SIMS spectra of polyesters are obtained from thin polymer films cast from solution on a silver substrate. A good solvent for a polumer solution disrupts intermolecular forces between polymer chains but leaves the polumer intact. Transesterification reactions are potentially useful for characterization of high molecular weight and intractable polyesters. Transesterification products of polyesters and trifluoroacetic acid or an integral number of polyester repeat units and an additional diol. The progress of such reactions was monitored using peak intensities of reactants and products in TOF-SIMS spectra. The increasing abundance of tagged ions indicates that the reaction has progressed with time.

• Journal of Conservation Science
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• v.34 no.2
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• pp.129-135
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• 2018

Scientific investigation of cultural heritage can provide important information to understand the context of the object. To know the characteristics of the material is also an essential part of objects management and conservation. However, the identification and characterization of organic dyes used in archaeological and historical textiles are often limited by the restrictions in sampling. To cope with the difficulties, applications of high-performance techniques of surface analysis, such as Time of Flight-Secondary Ion Mass Spectra (TOF-SIMS) could be considered as a non or micro-destructive option. This study aims to examine the applicability of TOF-SIMS analysis to the detection of organic dyes from historical textiles. A group of silk fabrics dyed with vegetable dyes were artificially photo-aged to different degrees and analyzed with TOF-SIMS. Molecular and fragment ions from indigo were successfully detected from the aged samples; however, only some fragment ions were observed from gardenia and safflower dyed fabrics. Further studies with actual historical samples with extended examination scope would be necessary to assess the validity of this technique.

• Polymer Science and Technology
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• v.24 no.5
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• pp.528-534
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• 2013

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.230.1-230.1
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• 2015

One of the major problems of biological ToF-SIMS imaging is the lack of protein and peptide imaging. Most of biological story telling is mianly based on proteins. The biological implication of lipid ToF-SIMS imaging would be much higher if protein imaging is provided together. Utilizing high secondary ion yields of metals, proteins can be ToF-SIMS imaged with nanoparticle tagged proteins. Nanoparticles such as Fe3O4, SiO2, PbS were used for imaing NeuN, MCH, Orexin A, ${\alpha}$ synucline, TH(Tryosine Hydroxylase) in mouse tissues with a spatial resolution of ${\sim}2{\mu}m$ using a TOF-SIMS. Lipids and neurotransmitters images obtained simultaneously with protein images were overlayed for more deeper understanding of neurobiology, which is not allowed by any other bioimaging technqiues. The protein images from TOF-SIMS were compared with confocal fluorescence microscopy and NanoSIMS images. A new sample preparation method for imaging single cell membranes in a tissue using the vibrotome technique to prepare a tissue slice without any fixation and freeze drying will be also presented briefly for Hippocampus and Hypothalamus tissues.

• Analytical Science and Technology
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• v.8 no.4
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• pp.715-722
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• 1995

The structural characterization for series of polyesters has been done by time-of-flight secondary ion mass spectrometry (TOF-SIMS). Polymer fragments and intact oligomers composed of large numbers of repeat units have been investigated. Transesterification of polyesters in trifluoroacetic acid (TFA) and chlorodifluoroacetic acid (CFA) was monitored and reaction products were identified using TOF-SIMS. The shapes and intensities of clusters in transesterification spectra show good agreement with the theoretical isotope pattern. TOF-SIMS spectra were used to obtain information about the progress of the transesterification reaction.

• Bulletin of the Korean Chemical Society
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• v.34 no.3
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• pp.815-819
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• 2013

Micropatterns of streptavidin and human epidermal carcinoma A431 cells were successfully imaged, as received and without any labeling, using cluster $Au_3{^+}$ ion beam-based time-of-flight secondary ion mass spectrometry (TOF-SIMS) together with a principal component analysis (PCA). Three different analysis ion beams ($Ga^+$, $Au^+$ and $Au_3{^+}$) were compared to obtain label-free TOF-SIMS chemical images of micropatterns of streptavidin, which were subsequently used for generating cell patterns. The image of the total positive ions obtained by the $Au_3{^+}$ primary ion beam corresponded to the actual image of micropatterns of streptavidin, whereas the total positive-ion images by $Ga^+$ or $Au^+$ primary ion beams did not. A PCA of the TOF-SIMS spectra was initially performed to identify characteristic secondary ions of streptavidin. Chemical images of each characteristic ion were reconstructed from the raw data and used in the second PCA run, which resulted in a contrasted - and corrected - image of the micropatterns of streptavidin by the $Ga^+$ and $Au^+$ ion beams. The findings herein suggest that using cluster-ion analysis beams and multivariate data analysis for TOF-SIMS chemical imaging would be an effectual method for producing label-free chemical images of micropatterns of biomolecules, including proteins and cells.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.279-279
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• 2013

차세대 태양전지로 주목받는 화합물 박막 태양전지(CIGS, CdTe, etc)는 광흡수계수가 매우 높아 얇은 두께의 광흡수층으로도 빛을 효과적으로 흡수할 수 있으므로 광흡수층의 역할이 매우 중요하며 이에 대한 정확한 정보와 이해는 필수적이다. 특히 GIGS 박막 태양전지의 정량 및 각 원소의 깊이 방향의 분포를 분석하는 것은 박막형 태양전지 개발에 크게 기여한다 [1,2]. 본 실험에서는 조성비를 알고 있는 균질한 CIGS박막을 표준시료로 사용하여 ICP-MS로 측정하여 평균농도를 구한 뒤 TOF-SIMS, D-SIMS, Auger Electron Spectroscopy (AES) 로 깊이 방향 분석 결과를 통해 상대감도(RSF)를 계산한 후 각 원소의 농도로 변환하여 정량분석 결과를 얻었다. 일반적으로 손쉽게 정량적인 정보를 얻는 AES에 비해 정량성이 떨어지는 TOF-SIMS와 D-SIMS는 스퍼터링시 사용되는 Cs 빔과 시료 내 금속과의 클러스터 이온(GaCs+와 InCs+)의 깊이 방향 조성을 이용하면 매트릭스 효과를 배제할 수 있어서 좀 더 정확한 정량 분석이 가능하므로 시료내 금속과 Cs 이 결합된 클러스터 이온의 깊이 방향 조성을 측정하여 각원소의 농도를 계산하였고 스퍼터링 에너지를 포함한 실험 변수에 따른 재현성 및 정량성의 차이를 비교분석하였다. 또한 CIGS층에 불순물로 들어 있는 미량원소들의 깊이 분포도도 함께 관찰하였다.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.23 no.2
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• pp.81-85
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• 2013

We performed analysis of composition and structure of coating layers by using ED-XRF and TOF-SIMS for some passion topaz of Swarovski which developed recently as new surface treatment of TCF (thermal color fusion) technique. In addition, we compared differences between Ti-coated topaz (Mystic topaz) and new treated colored topazes (passion topaz) with magnification observation and simplified durability test. As a result, we can observe similar characteristic clues in Ti-coated topaz and passion topaz by magnified observation. According to results of depth profile by TOF-SIMS, we can know that topaz is treated by multi-layer coating or surface diffusion coating. Moreover, the passion topaz which is treated by chemical reaction between metal elements shows more stable chemical resistance and higher Mohs' hardness than Ti-coated topaz.

• Analytical Science and Technology
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• v.10 no.5
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• pp.1087-1104
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• 1997

• Journal of the Mineralogical Society of Korea
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• v.18 no.2
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• pp.127-134
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• 2005

Although the bulk composition of materials is one of the major considerations in extractive metallurgy and environmental science, surface composition and topography control surface reactivity, and consequently play a major role in determining metallurgical phenomena and pollution by heavy metals and organics. An understanding of interaction mechanisms of different chemical species at the mineral surface in an aqueous media is very important in natural environment and metallurgical processing. X-ray photoelectron spectroscopy (XPS) has been used as an ex-situ analytical technique, but the material to be analyzed can be any size from $100\;{\mu}m$ up to about 1 cm. It can also measure mixed solids powders, but it is impossible to ascertain the original source of resulting x-ray signals where they were emitted from, since it radiates and scans the macro sample surface area. The study demonstrated the ability of TOF-SIMS to detect individual organic species on the surfaces of mineral particles from plant samples and showed that the TOF-SIMS techniques provides an excellent tool for establishing the surface compositions of mineral grains and relative concentrations of chemicals on mineral species.