Facile preparation of agarose-chitosan hybrid materials and nanocomposite ionogels using an ionic liquid via dissolution, regeneration and sol-gel transition

We report simultaneous dissolution of agarose (AG) and chitosan (CH) in varying proportions in an ionic liquid (IL), 1-butyl-3-methylimidazolium chloride [C4mim][Cl]. Composite materials were constructed from AG-CH-IL solutions using the antisolvent methanol, and IL was recovered from the solutions. Composite materials could be uniformly decorated with silver oxide (Ag2O) nanoparticles (Ag NPs) to form nanocomposites in a single step by in situ synthesis of Ag NPs in AG-CH-IL sols, wherein the biopolymer moiety acted as both reducing and stabilizing agent. Cooling of Ag NPs-AG-CH-IL sols to room temperature resulted in high conductivity and high mechanical strength nanocomposite ionogels. The structure, stability and physiochemical properties of composite materials and nanocomposites were characterized by several analytical techniques, such as Fourier transform infrared (FTIR), CD spectroscopy, differential scanning colorimetric (DSC), thermogravimetric analysis (TGA), gel permeation chromatography (GPC), and scanning electron micrography (SEM). The result shows that composite materials have good thermal and conformational stability, compatibility and strong hydrogen bonding interactions between AG-CH complexes. Decoration of Ag NPs in composites and ionogels was confirmed by UV-Vis spectroscopy, SEM, TEM, EDAX and XRD. The mechanical and conducting properties of composite ionogels have been characterized by rheology and current-voltage measurements. Since Ag NPs show good antimicrobial activity, Ag NPs -AG-CH composite materials have the potential to be used in biotechnology and biomedical applications whereas nanocomposite ionogels will be suitable as precursors for applications such as quasi-solid dye sensitized solar cells, actuators, sensors or electrochromic displays

Agarose processing in protic and mixed protic–aprotic ionic liquids : dissolution, regeneration and high conductivity, high strength ionogels

We have shown that low viscosity alkyl or hydroxyalkyl ammonium formate (ILs) can dissolve agarose, and higher dissolution can be achieved in the mixed, alkyl or hydroxyalkyl ammonium + imidazolium or pyridinium ILs. The polarity parameters α, β, π*, ET(30) and ETN of these IL systems were measured to explain their dissolution ability for agarose. Dissolved agarose was either regenerated using methanol as a precipitating solvent or ionogels were formed by cooling the agarose–IL solutions to ambient temperature. Exceptionally high strength ionogels were obtained from the agarose solutions in N-(2-hydroxyethyl)-ammonium formate or its mixture with 1-butyl-3-methylimidazolium chloride. Regenerated material and ionogels are characterized for their possible degradation/conformational changes and gel properties (thermal hysteresis, strength, viscoelasticity and conductivity) respectively. A high strength, high conducting ionogel was demonstrated to be able to build an electrochromic window. Such ionogels can also be utilized for other soft matter electronic devices and biomedical applications

Effect of flocculating agents on solubility behavior of calcium sulfate dihydrate (gypsum) in aqueous sodium chloride system and solution properties at 35 °C

The effect of addition of flocculating agents, viz., alum (KAl(SO4)2·12H2O) (up to 10 wt%) and polyaluminum chloride ([Al(OH)aClb]n, a >1.05; n~15) (up to 6 wt%) on the solubility behavior of calcium sulfate dihydrate (gypsum, CaSO4·2H2O) in aqueous NaCl solutions has been examined at 35 °C. The solubility of CaSO4·2H2O decreases with the addition of alum while it increases with the addition of polyaluminum chloride without any significant shift in solubility maximum. Density (ρ) and speed of sound (u) have also been determined for the quaternary systems (CaSO4·2H2O+NaCl+alum/PAC+H2O) at 35 °C and used to estimate solution isentropic compressibility (κs) and ion-hydration (nh) characteristics. Empirical equations describing the s, ρ, u and κs as a function of solution composition are presented.

Tuning the physicochemical properties of protic-aprotic ionic liquids upon reciprocal binary mixing

The alterations in properties of protic/aprotic (2-hydroxyethylammonium formate)/ 1-butyl-3-methylimidazolium methyl sulfate) ionic liquids (ILs), based on reciprocal binary mixing concept ([A][B][X][Y]) have been investigated by studying the density, speed of sound, and viscosity of mixtures as a function of temperature. The volume of mixing, isentropic compressibility, excess molar isentropic compressibilities and activation energy of viscous flow have been derived, which indicate a very high level of non-ideality in the mixtures desired to take advantage of improved solvent properties. FTIR spectral analysis and solvatochromic parameters (normalized Reichardt’s parameter, dipolarity/polarizibility, hydrogen bond donor and acceptor coefficients) determined through the solvatochromic probes have been utilized to examine the hydrogen bonding and ion-ion interactions prevailing in the studied systems. Although significant alterations in hydrogen bonding and ion-ion interactions are observed, dispersion type interactions dominate over chemical interactions as indicated by a high positive deviations in the volumes of mixing

Pan-cancer Alterations of the MYC Oncogene and Its Proximal Network across the Cancer Genome Atlas

Although theMYConcogene has been implicated incancer, a systematic assessment of alterations ofMYC, related transcription factors, and co-regulatoryproteins, forming the proximal MYC network (PMN),across human cancers is lacking. Using computa-tional approaches, we define genomic and proteo-mic features associated with MYC and the PMNacross the 33 cancers of The Cancer Genome Atlas.Pan-cancer, 28% of all samples had at least one ofthe MYC paralogs amplified. In contrast, the MYCantagonists MGA and MNT were the most frequentlymutated or deleted members, proposing a roleas tumor suppressors.MYCalterations were mutu-ally exclusive withPIK3CA,PTEN,APC,orBRAFalterations, suggesting that MYC is a distinct onco-genic driver. Expression analysis revealed MYC-associated pathways in tumor subtypes, such asimmune response and growth factor signaling; chro-matin, translation, and DNA replication/repair wereconserved pan-cancer. This analysis reveals insightsinto MYC biology and is a reference for biomarkersand therapeutics for cancers with alterations ofMYC or the PMN

<span style="font-size:13.0pt;font-family: "Times New Roman";mso-fareast-font-family:"Times New Roman";mso-bidi-font-family: Mangal;mso-ansi-language:EN-GB;mso-fareast-language:EN-US;mso-bidi-language: HI" lang="EN-GB">Effect of flocculating agents on solubility behavior of c<span style="font-size:13.0pt;font-family:"Times New Roman";mso-fareast-font-family: Calibri;mso-bidi-font-family:Mangal;mso-ansi-language:EN-IN;mso-fareast-language: EN-US;mso-bidi-language:HI">alcium sulfate dihydrate (gypsum)<span style="font-size:13.0pt;font-family:"Times New Roman";mso-fareast-font-family: "Times New Roman";mso-bidi-font-family:Mangal;mso-ansi-language:EN-GB; mso-fareast-language:EN-US;mso-bidi-language:HI" lang="EN-GB"> in aqueous sodium chloride system and solution properties at 35 °C</span></span></span>

57-63The effect of addition of flocculating agents, viz., alum (KAl(SO4)2·12H2O) (up to 10 wt%) and polyaluminum chloride ([Al(OH)aClb]n, a >1.05; n~15) (up to 6 wt%) on the solubility behavior of calcium sulfate dihydrate (gypsum, CaSO4·2H2O)<span style="mso-fareast-font-family:Calibri;mso-bidi-font-family:TT1AF9o00; mso-ansi-language:EN-IN"> in aqueous NaCl solutions has been examined at 35 °C. The solubility of CaSO4·2H2O decreases with the addition of alum while it increases with the addition of polyaluminum chloride without any significant shift in solubility maximum. Density (ρ) and speed of sound (u) have also been determined for the quaternary systems (CaSO4·2H2O+NaCl+alum/PAC+H2O) at 35 °C and used to estimate solution isentropic compressibility (κs) and ion-hydration (nh) characteristics. Empirical equations describing the s, ρ, u and <i style="mso-bidi-font-style: normal">κs as a function of solution composition are presented. </span

Functionalized Agarose Self-Healing Ionogels Suitable for Supercapacitors

Agarose has been functionalized (acetylated/carbanilated) in an ionic liquid (IL) medium of 1-butyl-3-methylimidazolium acetate at ambient conditions. The acetylated agarose showed a highly hydrophobic nature, whereas the carbanilated agarose could be dissolved in water as well as in the IL medium. Thermoreversible ionogels were obtained by cooling the IL sols of carbanilated agarose at room temperature. The ionogel prepared from a protic-aprotic mixed-IL system (1-butyl-3-methylimidazolium chloride and N-(2-hydroxyethyl)ammonium formate) demonstrated a superior self-healing property, as confirmed from rheological measurements. The superior self-healing property of such an ionogel has been attributed to the unique inter-intra hydrogen-bonding network of functional groups inserted in the agarose. The ionogel was tested as a flexible solid electrolyte for an activated-carbon-based supercapacitor cell. The measured specific capacitance was found to be comparable with that of a liquid electrolyte system at room temperature and was maintained for up to 1000 charge-discharge cycles. Such novel functionalized-biopolymer self-healing ionogels with flexibility and good conductivity are desirable for energy-storage devices and electronic skins with superior lifespans and robustness. © 2015 WILEY-VCH Verlag GmbH &amp; Co. KGaA, Weinheim.

Tuning the physicochemical properties of protic-aprotic ionic liquids upon reciprocal binary mixing

544-553<span style="font-size:9.0pt;font-family: " times="" new="" roman";mso-fareast-font-family:"times="" roman";mso-bidi-font-family:="" "times="" roman";mso-ansi-language:en-gb;mso-fareast-language:en-us;="" mso-bidi-language:hi"="" lang="EN-GB">The alterations in properties of protic/aprotic (2-hydroxyethylammonium formate)/ 1-butyl-3-methylimidazolium methyl sulfate) ionic liquids (ILs), based on reciprocal binary mixing concept ([A][B][X][Y]) have been investigated by studying the density, speed of sound, and viscosity of mixtures as a function of temperature. The volume of mixing, isentropic compressibility, excess molar isentropic compressibilities and activation energy of viscous flow have been derived, which indicate a very high level of non-ideality in the mixtures desired to take advantage of improved solvent properties. FTIR spectral analysis and solvatochromic parameters (normalized Reichardt’s parameter, dipolarity/polarizibility, hydrogen bond donor and acceptor coefficients) determined through the solvatochromic probes have been utilized to examine the hydrogen bonding and ion-ion interactions prevailing in the studied systems. Although significant alterations in hydrogen bonding and ion-ion interactions are observed, dispersion type interactions dominate over chemical interactions as indicated by a high positive deviations in the volumes of mixing.</span

Temperature Dependence of Physical Properties of Amino Acid Ionic Liquid Surfactants

The density (ρ), speed of sound (<i>u</i>), and refractive index (<i>n</i>_D) of amino acid ionic liquid surfactants (AAILSs) prepared from natural amino acids, l-glycine, l-alanine, l-valine, l-glutamic acid, and l-proline, and sodium lauryl sulfate have been measured in the temperature range from (288.15 to 343.15) K. The temperature dependence of density has been used to calculate the coefficient of thermal expansion (α). Using the experimental ρ and <i>u</i> values, the isentropic compressibility (κ_<i>s</i>) has been calculated for various AAILSs. The molar refraction (<i>R</i>_M) has been calculated from experimental <i>n</i>_D values in the temperature range from (288.15 to 343.15) K. Refractive indices of ILs were found higher than those of normal organic liquids but are comparable to long hydrocarbon chain organic solvents

Deep eutectic solvents as attractive media for CO2 capture

We report a family of deep eutectic solvents (DESs) consisting of various hydrogen bonding donor-acceptor pairs as CO2 capturing media. These DESs capture CO2 via carbamate formation upon reaction between their hydrogen bonding donor units and CO2. Among the members tested herein, a DES made up of monoethanolamine hydrochloride-ethylenediamine exhibits an unprecedentedly high gravimetric uptake of 33.7 wt% with good initial kinetics (25.2 wt% uptake within 2.5 min) and recyclability. The given DES also shows sustainable performance in the presence of water, decent tolerance against temperature rise, and a relatively low heat of absorption which is attractive for regeneration. Even with the high gravimetric uptake, the DES has a far more suppressed corrosiveness compared to its pure monoethanolamine and ethylenediamine counterparts due to low oxygen/moisture permeability and the hydrogen bonding network that alleviates the corrosion redox cycle. The observed excellent properties in various key aspects of CO2 capture suggest that DESs are strong candidates to replace the conventional monoethanolamine-based scrubbing technology and are worth further exploration.