Papers by Keyword: DMSO

Abstract: Regenerating cellulose (cotton) through anti-solvent precipitation is a promising method for recycling textile waste. The selection of an anti-solvent during the regeneration of cellulose depends on its molecular structure. In this study, dissolved cotton in dimethyl sulfoxide (DMSO) was treated with five different anti-solvents for cellulose: sodium hydroxide (NaOH), hydrochloric acid (HCl), calcium chloride (CaCl₂) solution, ethanol, and water. The results show that water is adequate in regenerating cotton by up to 20%. The FTIR study was performed to analyze changes in the chemical structure of regenerated cotton following regeneration with different solvents. The C-H bend peak observed around 800-900 cm-1 confirmed that the main β-glycosidic bonds in cellulose were retained across all samples after the regeneration process. Each anti-solvent altered the cellulose structure by modifying hydrogen bonding through specific rearrangements in the chain packing. This is reflected in the lateral-order index (LOI), which represents the ratio of crystalline to amorphous regions. By comparing the lateral-order index (LOI) A1430/A886 from FTIR peak and UV-vis absorbance, the result confirmed that the ranking of effective regeneration using anti-solvent was H2O > NaOH > CaCl₂, ethanol > HCl.

Abstract: Graphene-based materials have been widely developed in various applications, both in electronics and optoelectronics. It is because of their attractive characteristics, such as flexible structure, large surface area, and excellent thermal, mechanical, and optoelectronic properties. In this research, the optical absorbance of coconut shell-based carbon materials was studied in the exfoliation process and the type of solvent. To determine the effect of optical absorption and particle size of graphene carbon from coconut shells on solvents, we used two types of solvents, namely Deionized (DI) water and a mixture of DMSO and DI (DMSO/DI) with a fraction of 1:10. The exfoliation process is carried out by dissolving graphene powder from coconut shell powder that has been synthesized and heated at 400°C into DI water and DMSO/DI mixture with a concentration of 0.01 g/ml. Ultrasonication is carried out with time variations of 60, 180, 300, and 420 minutes. After ultrasonication for 420 minutes, the absorbance peak was at 241 nm with an average particle size of 134 nm in the solvent DMSO/DI mixture. For the DI solvent, the absorbance peak was at 243 nm with an average particle size of 198 nm. This study showed that the DMSO/DI mixed solvent with a fraction of 1:10 could produce a smaller average particle size than the DI solvent, but the absorbance spectrum is less clear at a wavelength of less than 240 nm compared to the DI water. Furthermore, these two solvents can be used to prepare graphenic carbon films from coconut shells because they are easy to obtain, cheap, and can reduce particle size by ultrasonication.

Abstract: The effect of DMSO on high concentrated cellulose-AMIMCl was studied in this paper. DMSO decreases the viscosity of cellulose solution obviously, however, the viscosity do not decrease more when the concentration of DMSO increases beyond 30wt%. Cellulose coil can be swelled after adding DMSO as a result of the low viscosity and more coil becomes more apart. The different order of mixture affect the solubility of solvent and DMSO as an excellent aprotic solvent do not affect the degradation of cellulose in AMIMCl.

Abstract: In the present study, we used an apatite-fiber scaffold (AFS) to culture P19.CL6 cells three-dimensionally. AFS was originally developed to use for the bone substitute and has high porosity and complex pore structure. The highly porous structure of AFS suggests it may be compatible for the in vitro reorganization of soft tissue. We previously showed the formation of small cell aggregates in AFS, and that culture in AFS increased the expression of cardiac-specific gene markers without the need for any inducing agent such as DMSO. However, it is difficult to evaluate the physiological function of cells in three-dimensional culture. In this study, we transformed P19.CL6 cells with the pTnnt2::GCaMP5G vector and observed the cells by fluorescence microscopy. pTnnt2::GCaMP5G consists of green fluorescent protein (GFP) fused with the Ca²⁺-sensitive domain of calmodulin; its expression is driven by a cardiomyocyte-specific promoter. We observed that the blinking of green fluorescence was synchronized to the beating of cardiomyocytes when the P19.CL6 cells were cultured in a dish, but blinking was not observed when the cells were cultured in AFS, even after 16 days. The expression of connexin 43 (Cx43) and enhanced Green Fluorescence Protein (EGFP) was examined by reverse transcriptase-polymerase chain reaction (RT-PCR). Cx43 is a gap junction protein expressed in cardiomyocytes that mediates cell-to-cell coupling. Although the expression of Cx43 and EGFP in transformed cells cultured in AFS was evident, fluorescence blinking of the cells was not observed. The results demonstrate that P19.CL6 cells cultured in AFS rapidly differentiated into early stage cardiomyocytes; however, additional modifications or developments are needed for further differentiation.

Abstract: A new protocol for trifluoromethyl-promoted oxidation of fischer-type N-Heterocyclic Carbene copper complexes has been developed by DMSO, which allows the preparation of imidazolinones from carbene complexes.

Abstract: a new rosin derivative—methylthiomethyl dehydroabietate has been synthesized from dehydroabietic acid and DMSO. The effects of reaction temperature, time, the amount of catalyst and mixing molar ratio of reactants on the yield have been investigated. The optimum reaction conditions were: the reactants were kept at 215 oC for 3h with dimethyl sulfoxide/ dehydroabietic acid mixing molar ratio of 22: 1 in the presence of 0.4% KOH catalyst ( based on the mass of dehydroabietic acid). The yield of product could reach 90%. The precise structure of the product was characterized as methylthiomethyl dehydroabietate by GC-MS, UV, FT-IR, High-Resolution Mass Spectrometry, ¹HNMR and ¹³C NMR.

Abstract: The changes of cell membrane permeability caused by dimethyl sulphoxide (DMSO) and ethanol, two commonly used solvents in study of water-insoluble elicitors, were investigated in suspension cultures of Taxus cuspidata. The extracellular medium became alkalinized in the case of DMSO while the medium pH fluctuated upon the addition of ethanol. When the content of DMSO or ethanol was larger than 2% (v/v), the concentration of intracellular malonyl dialdehyde (MDA) increased remarkably at day 5 compared to that of the control, while that of the extracellular MDA less changed at a DMSO content of below 2% (v/v) and increased rapidly within 15 min at a DMSO content of 4% (v/v). The electrical conductivity (EC) decreased slightly when DMSO content was below 2% (v/v) but increased markedly at day 5 when DMSO content reached 4% (v/v). EC less varied when the content of ethanol was below 0.4% (v/v) but changed obviously when the ethanol content was larger than 1% (v/v). The cell membrane integrity hardly broke in the case of small concentration of DMSO (below 1%, v/v), but the presence of even small amount of ethanol (0.4%, v/v) caused cell membrane integrity lost partly, especially long time contact. It is thus concluded that DMSO is a more suitable solvent for water-insoluble elicitors compared to ethanol especially at low concentration levels.

Abstract: Titania nanotube arrays were synthesized via anodic oxidization of titanium foil in dimethyl sulfoxide (DMSO) solution containing 2 wt% HF and 3 wt% H2O at 40 V. The microstructure of the arrays was characterized with scanning electron microscopy (SEM). The results show that morphology of titania nanotube arrays is evidently influenced by the anodization time, and with the extension of oxidation time, the better morphology could be obtained. The possible formation mechanism of titania nanotube arrays has been discussed.

Abstract: The aim of this study is to elaborate electro-rheological fluids based on kaolinite. the scientific characterization made it possible the identification of the composite nature and the checking of the intercalation of the polymer among the clay particles The rheological behaviour of the fluid depends on the electric field. A yield stress of the suspensions is observed, which increases with the applied electric field. An interpretation based on the different modes of association between the clay particles is proposed to account qualitatively for the observed behaviour.

Abstract: The introduction of metal gates and high-k dielectrics in FEOL and porous ULK dielectrics in BEOL presents severe issues [1] and leads to the requirement of new chemistries and processes. A major challenge in cleaning is the removal of photoresist (PR) in both FEOL and BEOL. In current semiconductor device fabrication flow, the photoresist strip process in FEOL is mostly achieved by applying a sequence of plasma ashing followed by a wet-clean step with sulfuric-peroxide mixture (SPM). But in general, ashing leads to strong oxidation or etching of silicon substrate. Hence, several approaches for ashless PR strip have been reported, such as hot SPM [2] and the combination of a pre-treatment using high velocity CO2 aerosol [3].