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Of Solvents (of + solvent)

Distribution by Scientific Domains
Polymers and Materials Science50%
Chemistry50%

Kinds of Of Solvents

  • variety of solvent
    		•

    Selected Abstracts

    Solvent-Resistant PDMS Microfluidic Devices with Hybrid Inorganic/Organic Polymer Coatings

    ADVANCED FUNCTIONAL MATERIALS, Issue 23 2009
    Bo-Yeol Kim
    Abstract This study presents a method for the fabrication of solvent-resistant poly(dimethylsiloxane) (PDMS) microfluidic devices by coating the microfluidic channel with a hybrid inorganic/organic polymer (HR4). This modification dramatically increases the resistance of PDMS microfluidic channels to various solvents, because it leads to a significant reduction in the rate of solvent absorption and consequent swelling. The compatibility of modified PDMS with a wide range of solvents is investigated by evaluating the swelling ratio measured through weight changes in a standard block. The HR4-modified PDMS microfluidic device can be applied to the formation of water-in-oil (W/O) and oil-in-water (O/W) emulsions. The generation of organic solvent droplets with high monodispersity in the microfluidic device without swelling problems is demonstrated. The advantage of this proposed method is that it can be used to rapidly fabricate microfluidic devices using the bulk properties of PDMS, while also increasing their resistance to various organic solvents. This high compatibility with a variety of solvents of HR4-modified PDMS can expand the application of microfluidic systems to many research fields. [source]

    Synthesis and Properties of Oligodeoxynucleotide Analogs with Bis(methylene) Sulfone Bridges

    HELVETICA CHIMICA ACTA, Issue 9 2003
    Bernd Eschgfäller
    A convergent, solution-phase synthesis was developed for the bis(methylene) sulfone-bridged oligodeoxynucleotide analogs (SNA) 5,-d(HOCH2 -Tso2Tso2Tso2Cso2Tso2Tso2Tso2T-CH2SO)-3, (35b) and 5,-d(HOCH2 -Tso2Tso2Tso2Tso2Tso2Tso2Tso2T-CH2SO)-3, (34c) (SO2 corresponds to CH2SO2CH2 instead of OP(O)(O,)(O). In these, the phosphodiester linkages are replaced by non-ionic bis(methylene) sulfone linkers. The general strategy involved convergent coupling of 3,,5,-bishomo- , - D -deoxyribonucleotide analogs functionalized at the 6,-end (CH2C(5,)) as bromides or mesylates and at the CH2C(3,) position as thiols, with the resulting thioether being oxidized to the corresponding sulfone. A single charge was introduced at the terminal CH2C(3,) position of the octamers to increase their solubility in water. During the synthesis, it became apparent that the key intermediates generated secondary structures through either folding or aggregation in a variety of solvents. This generated unusual reactivity and was unique for very similar structures. For example, although the dimeric thiol d(BzOCH2 -Tso2C-CH2SH) (14b) was a well-behaved synthetic intermediate, the tetrameric thiol d(TrOCH2 -Tso2Tso2Tso2toC-CH2SH) derived from the corresponding thioacetate was rapidly converted to a disulfide by very small amounts of oxidant (28,29, Scheme,6), while the analogous tetrameric thiol d(BzOCH2 -Tso2TsTso2T-CH2SH) (26), differing only by a single heterocycle, was oxidized much more slowly (Bz=PhCO, Tr=Ph3C, to=2-MeC6H4CO (at N4 of dc)). The sequence-dependent reactivity, well known in many classes of natural products (including polypeptides), is not prominent in natural oligonucleotides. These results are discussed in light of the proposal that the repeating negative charge in nucleic acids is key to their ability to serve as genetic molecules, in particular, their capability to support Darwinian evolution. The ability of 5,-d(HOCH2 -Tso2Tso2Tso2Cso2Tso2Tso2Tso2T-CH2SO)-3, (35b) to bind as a third strand to duplex DNA was also examined. No triple-helix-forming propensity was detected in this molecule. [source]

    Chemically Derived Graphene Oxide: Towards Large-Area Thin-Film Electronics and Optoelectronics

    ADVANCED MATERIALS, Issue 22 2010
    Goki Eda
    Abstract Chemically derived graphene oxide (GO) possesses a unique set of properties arising from oxygen functional groups that are introduced during chemical exfoliation of graphite. Large-area thin-film deposition of GO, enabled by its solubility in a variety of solvents, offers a route towards GO-based thin-film electronics and optoelectronics. The electrical and optical properties of GO are strongly dependent on its chemical and atomic structure and are tunable over a wide range via chemical engineering. In this Review, the fundamental structure and properties of GO-based thin films are discussed in relation to their potential applications in electronics and optoelectronics. [source]

    The effect of adding Crabtree's catalyst to rhodium black in direct hydrogen isotope exchange reactions

    JOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 9 2009
    Søren Christian Schou
    Abstract A new catalytic system based on rhodium black using Crabtree's catalyst as an additive for direct hydrogen isotope exchange in aromatic compounds has been investigated. The level of deuterium incorporation can be improved from for example 16 to 93%. The new catalyst mixture tolerates a variety of solvents. Copyright © 2009 John Wiley & Sons, Ltd. [source]

    Solvolyses of naphthoyl chlorides.

    JOURNAL OF PHYSICAL ORGANIC CHEMISTRY, Issue 11 2002
    Grunwald, Solvent effect, Winstein correlation analyses with YxBnCl scales
    Abstract The solvolyses of 1-naphthoyl (2), 2-naphthoyl (3), 4-methyl-1-naphthoyl (4) and 6-methoxy-2-naphthoyl (5) chlorides in a variety of solvents were studied, and correlation analyses by using the single- and dual-parameter Grunwald,Winstein equations were examined. An excellent linear relationship (R,=,0.995) for 4, log (k/k0),=,0.733YxBnCl,+,0.269NOTs, was observed. An SN1-like mechanism with decreasing extent of nucleophilic solvent participation was found in the solvolysis of 2 and 4. 2-Naphthoyl chloride is likely to have a mechanism at the borderline of SN1-like dissociation and an addition,elimination process. 6-Methoxy-2-naphthoyl chloride shows more SN1-like character than 3 and is associated with nucleophilic solvent intervention more pronounced than that for 2 and 4. The applicability and the advantages of using the YxBnCl scale for different types of substrates are discussed. Copyright © 2002 John Wiley & Sons, Ltd. [source]

    Preparation of a variety of fluoroalkyl end-capped N -(1,1-dimethyl-3-oxobutyl)acrylamide oligomer/silica nanocomposites possessing no weight loss characteristic at 800°C

    POLYMERS FOR ADVANCED TECHNOLOGIES, Issue 7 2008
    Hideo Sawada
    Abstract A variety of fluoroalkyl end-capped N -(1,1-dimethyl-3-oxobutyl)acrylamide oligomer [RF -(DOBAA)n - RF]/silica nanocomposites, in which the oligomer contents are 18,96%, were prepared by reactions of the corresponding fluorinated oligomer with tetraethoxysilane and silica nanoparticles under alkaline conditions. Each fluorinated oligomer/silica composite thus obtained is nanometer size-controlled very fine particles (22,68,nm) possessing a good dispersibility and stability in a variety of solvents including water. Interestingly, the weight loss of RF -(DOBAA)n -RF/silica nanocomposites, in which the oligomer contents are 18,72%, were not observed at all even at 800°C, as well as the original silica nanoparticles, although the corresponding sub-micrometer size-controlled RF - (DOBAA)n -RF/silica composites (particle size: 359,nm) decomposed completely at 800°C to afford the weight loss in proportion to the content of RF -(DOBAA)n -RF oligomer in composites. On the other hand, a slight weight loss of RF -(DOBAA)n -RF/silica nanocomposites, in which the oligomer contents are 75,94%, was observed at 800°C compared to that of the original silica nanoparticles. Copyright © 2008 John Wiley & Sons, Ltd. [source]