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A K Arof - One of the best experts on this subject based on the ideXlab platform.
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conductivity and x ray photoelectron studies on Lithium Acetate doped chitosan films
Carbohydrate Polymers, 2004Co-Authors: M Z A Yahya, A K ArofAbstract:Abstract Chitosan, ethylene carbonate (EC) and Lithium Acetate (LiOAc) were mixed in the desired proportions and dissolved in 100 ml of 1% acetic acid solutions. The solutions were then poured into various petri dishes and left to form films at room temperature. Complexation was confirmed by X-ray photoelectron spectroscopy (XPS). The Lithium signal can be deconvoluted into three gaussian component peaks. One of the peaks at ∼55 eV is attributed to Li–N interaction. The nitrogen signal can be deconvoluted into two gaussian component peaks. The peak at ∼403.1 eV is attributed to N–Li interaction. The electrical conductivity of all samples was calculated using the bulk resistance value obtained from the complex impedance plot in the frequency range between 1 kHz and 1 MHz. The highest electrical conductivity obtained for the film containing LiOAc is 7.6×10 −6 S cm −1 at room temperature. The plot of conductivity, σ versus dopant content indicates that σ increases with increasing dopant content up to a dopant amount of 0.8 g LiOAc. The plot of ln σT versus 10 3 / T for each Lithium Acetate sample between 298 and 363 K shows beys Arrhenius behavior indicating that the conductivity occurs by way of some thermally assisted mechanism. The chitosan based samples may have potential use in replacing the liquid components of electrochromic devices.
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effect of oleic acid plasticizer on chitosan Lithium Acetate solid polymer electrolytes
European Polymer Journal, 2003Co-Authors: M Z A Yahya, A K ArofAbstract:Abstract Plasticized polymer electrolytes composed of chitosan as the host polymer, oleic acid (OA) as the plasticizer and Lithium Acetate (LiOAc) as the doping salt were prepared by the solution cast technique. These complexes with different amounts of salts and plasticizers were investigated as possible ionic conducting polymers. The highest ionic conductivity of the plasticized chitosan–LiOAc was ∼10 −5 S cm −1 for the film containing 40.0 wt.% LiOAc and 10.0 wt.% of OA. Conductivity for the plasticized LiOAc-doped chitosan polymer was also studied as a function of temperature between 300 and 363 K. The plot of ln( σT ) versus 10 3 /T for each sample obeys Arrhenius rule indicating the conductivity to be thermally assisted. XRD and FTIR spectroscopy techniques have been used for the structural studies.
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studies on Lithium Acetate doped chitosan conducting polymer system
European Polymer Journal, 2002Co-Authors: M Z A Yahya, A K ArofAbstract:Abstract The structure of chitosan contains the amine group that can act as electron donors. Complexation between chitosan and the salt can be proven by infrared and X-ray photoelectron spectroscopy methods. The NH2, NH3+ and OC-NHR vibrations which can be observed at 1590, 1560 and 1650 cm−1 shift to lower wave numbers when the complexes are formed. The after deconvolution Li 1s core level spectrum of the chitosan–salt complexes can contain several gaussian components one of which has a binding energy peak at 55.2 eV which signifies Li–N interaction. The component that peaks at ∼403 eV in the N 1s core level spectrum complements the proof of N–Li interaction. The highest conductivity achieved for a plasticized chitosan–salt complex is of the order 10−6 S/cm using Lithium Acetate as the doping salt. Transference number studies prove that this material is ionic conductor and from transient ionic current studies that mobility of the ions is of the order of 10−4 cm2/V s.
Teruaki Mukaiyama - One of the best experts on this subject based on the ideXlab platform.
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Lewis Base-catalyzed Cyanomethylation of Aldimines with Trimethylsilylacetonitrile
Chemistry Letters, 2005Co-Authors: Yoshikazu Kawano, Hidehiko Fujisawa, Teruaki MukaiyamaAbstract:A catalytic cyanomethylation of various aldimines with trimethylsilylacetonitrile (TMSCH2CN) in the presence of Lewis bases such as Lithium Acetate or benzoate proceeded smoothly to afford the corr...
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Lithium Acetate catalyzed trifluoromethylation of carbonyl compounds with trifluoromethyl trimethylsilane
Chemistry Letters, 2005Co-Authors: Teruaki Mukaiyama, Yoshikazu Kawano, Hidehiko FujisawaAbstract:Trifluoromethylation of various aldehydes and ketones with (trifluoromethyl)trimethylsilane in the presence of a catalytic amount of a Lewis base such as Lithium Acetate proceeded smoothly to affor...
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Lithium Acetate catalyzed aldol reaction between aldehyde and trimethylsilyl enolate in anhydrous or water containing n n dimethylformamide
Bulletin of the Chemical Society of Japan, 2004Co-Authors: Takashi Nakagawa, Hidehiko Fujisawa, Yuzo Nagata, Teruaki MukaiyamaAbstract:Lithium Acetate (AcOLi)-catalyzed aldol reactions between trimethylsilyl enolates and aldehydes proceed smoothly in anhydrous DMF or pyridine to afford the corresponding aldols in good to high yields under weakly-basic conditions (Tables 1-5). This catalytic aldol reaction is performed smoothly also by using other metal carboxylates that are easily prepared in situ by treating carboxylic acids with Lithium carbonate (Li 2 CO 3 ) (Table 2, Scheme 5). In order to show the effect of mild and readily-available AcOLi catalyst, the aldol reaction in water-containing DMF was studied in detail. AcOLi and various metal carboxylates behaved as effective Lewis base catalysts in aldol reactions between trimethylsilyl enolate and aldehydes in DMF-H 2 O (50:1) (Tables 6, 7). One of the most characteristic points of the above reaction that took place in water-containing DMF is that the aldehydes having a free amide and a hydroxy or even a carboxyl group reacted smoothly and afforded the desired aldols 29-31 in moderate to high yields (Table 8, Entries 12-15). Trimethylsilyl enolates derived from carboxylic esters behaved similarly as excellent nucleophiles in the above reaction. This is the first example of Lewis base-catalyzed aldol reactions to afford the desired aldol adducts even when silyl enolates derived from carboxylic esters were used in a water-containing organic solvent.
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Lithium Acetate catalyzed michael reaction between trimethylsilyl enolate and α β unsaturated carbonyl compound
Chemistry Letters, 2004Co-Authors: Takashi Nakagawa, Hidehiko Fujisawa, Yuzo Nagata, Teruaki MukaiyamaAbstract:Lithium Acetate-catalyzed Michael reaction between trimethylsilyl enolates and α,β-unsaturated carbonyl compounds in DMF proceeded smoothly to afford the corresponding Michael-adducts in good to hi...
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Lithium Acetate catalyzed mannich type reaction between trimethylsilyl enolates and aldimines in a water containing dmf
Chemistry Letters, 2004Co-Authors: Eiki Takahashi, Hidehiko Fujisawa, Teruaki MukaiyamaAbstract:Lithium Acetate-catalyzed Mannich-type reaction between trimethylsilyl enolates and aldimines proceeded smoothly in dry or even in a water-containing DMF to afford the corresponding β-amino carbonyl compounds in good to high yields under mild conditions.
M Z A Yahya - One of the best experts on this subject based on the ideXlab platform.
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conductivity and x ray photoelectron studies on Lithium Acetate doped chitosan films
Carbohydrate Polymers, 2004Co-Authors: M Z A Yahya, A K ArofAbstract:Abstract Chitosan, ethylene carbonate (EC) and Lithium Acetate (LiOAc) were mixed in the desired proportions and dissolved in 100 ml of 1% acetic acid solutions. The solutions were then poured into various petri dishes and left to form films at room temperature. Complexation was confirmed by X-ray photoelectron spectroscopy (XPS). The Lithium signal can be deconvoluted into three gaussian component peaks. One of the peaks at ∼55 eV is attributed to Li–N interaction. The nitrogen signal can be deconvoluted into two gaussian component peaks. The peak at ∼403.1 eV is attributed to N–Li interaction. The electrical conductivity of all samples was calculated using the bulk resistance value obtained from the complex impedance plot in the frequency range between 1 kHz and 1 MHz. The highest electrical conductivity obtained for the film containing LiOAc is 7.6×10 −6 S cm −1 at room temperature. The plot of conductivity, σ versus dopant content indicates that σ increases with increasing dopant content up to a dopant amount of 0.8 g LiOAc. The plot of ln σT versus 10 3 / T for each Lithium Acetate sample between 298 and 363 K shows beys Arrhenius behavior indicating that the conductivity occurs by way of some thermally assisted mechanism. The chitosan based samples may have potential use in replacing the liquid components of electrochromic devices.
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effect of oleic acid plasticizer on chitosan Lithium Acetate solid polymer electrolytes
European Polymer Journal, 2003Co-Authors: M Z A Yahya, A K ArofAbstract:Abstract Plasticized polymer electrolytes composed of chitosan as the host polymer, oleic acid (OA) as the plasticizer and Lithium Acetate (LiOAc) as the doping salt were prepared by the solution cast technique. These complexes with different amounts of salts and plasticizers were investigated as possible ionic conducting polymers. The highest ionic conductivity of the plasticized chitosan–LiOAc was ∼10 −5 S cm −1 for the film containing 40.0 wt.% LiOAc and 10.0 wt.% of OA. Conductivity for the plasticized LiOAc-doped chitosan polymer was also studied as a function of temperature between 300 and 363 K. The plot of ln( σT ) versus 10 3 /T for each sample obeys Arrhenius rule indicating the conductivity to be thermally assisted. XRD and FTIR spectroscopy techniques have been used for the structural studies.
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studies on Lithium Acetate doped chitosan conducting polymer system
European Polymer Journal, 2002Co-Authors: M Z A Yahya, A K ArofAbstract:Abstract The structure of chitosan contains the amine group that can act as electron donors. Complexation between chitosan and the salt can be proven by infrared and X-ray photoelectron spectroscopy methods. The NH2, NH3+ and OC-NHR vibrations which can be observed at 1590, 1560 and 1650 cm−1 shift to lower wave numbers when the complexes are formed. The after deconvolution Li 1s core level spectrum of the chitosan–salt complexes can contain several gaussian components one of which has a binding energy peak at 55.2 eV which signifies Li–N interaction. The component that peaks at ∼403 eV in the N 1s core level spectrum complements the proof of N–Li interaction. The highest conductivity achieved for a plasticized chitosan–salt complex is of the order 10−6 S/cm using Lithium Acetate as the doping salt. Transference number studies prove that this material is ionic conductor and from transient ionic current studies that mobility of the ions is of the order of 10−4 cm2/V s.
Antony M. Carr - One of the best experts on this subject based on the ideXlab platform.
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transformation of schizosaccharomyces pombe Lithium Acetate dimethyl sulfoxide procedure
CSH Protocols, 2016Co-Authors: Johanne M. Murray, Adam T. Watson, Antony M. CarrAbstract:Transformation of Schizosaccharomyces pombe with DNA requires the conditioning of cells to promote DNA uptake followed by cell growth under conditions that select and maintain the plasmid or integration event. The three main methodologies are electroporation, treatment with Lithium cations, and transformation of protoplasts. The Lithium Acetate method described here is widely used because it is simple and reliable.
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Transformation of schizosaccharomyces pombe: Lithium Acetate/dimethyl sulfoxide procedure
Cold Spring Harbor Protocols, 2016Co-Authors: Johanne M. Murray, Adam T. Watson, Antony M. CarrAbstract:Transformation ofSchizosaccharomyces pombewith DNA requires the conditioning of cells to promote DNA uptake followed by cell growth under conditions that select and maintain the plasmid or integration event. The three main methodologies are electroporation, treatment with Lithium cations, and transformation of protoplasts. The Lithium Acetate method described here is widely used because it is simple and reliable.
Antoni Martinezandreu - One of the best experts on this subject based on the ideXlab platform.
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isobaric vapor liquid equilibria for water acetic acid Lithium Acetate
Journal of Chemical & Engineering Data, 2001Co-Authors: Ernesto Vercher, And Isabel M Vazquez, Antoni MartinezandreuAbstract:Isobaric vapor−liquid equilibria for all of the binary and ternary mixtures of water, acetic acid, and Lithium Acetate have been measured at 100.00 kPa using a recirculating still. To take into account the association of the acetic acid in the vapor phase, Marek's chemical theory has been considered. The three experimental binary data sets have been independently correlated using Mock's electrolyte NRTL model, and the binary parameters estimated for each binary system have been used to predict the ternary vapor−liquid equilibrium using the same model. No ternary parameters were required. The ternary equilibrium values obtained in this way agreed well with the experimental values.