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The most plentiful carbohydrate present on earth is in the form of cellulose which has a tremendous capacity to manufacture second or third-generation biofuels and other valuable metabolites. Cellulose is a significant part of banana pseudostem (BP) squander that causes numerous environmental issues. Hence, disposal of BP is nowadays a major obstacle for Indian farmers because of immense volume, delay in decay raise in a foul smell during debasement which attracts pests and insects to farm. The present study reports the identification of potential isolates, which efficiently debase BP. Out of many isolates, NAULH-4 showed the uppermost decomposition rate of cellulose, hemicellulose, and lignin at 45 °C and pH 8 up to 28 days incubation. Moreover, the taxonomic characterization using phenotypic microarray (PM) technology directs that the isolate NAULH-4 belongs to Bacillus with 0.71 SIM index in metabolic pathway network which is reinforced by 16 s rRNA analysis. Molecular data reveal that NAULH-4 contain laccase, xylanase, and cellulase gene. Overall, Bacillus wakoensis NAULH-4 can be applicable for promising microbe for the conversion of BP waste into value-added metabolites.

Metal-free imidazolium-based ionic liquid (IL) Bronsted acids 1-methyl imidazolium hydrogen sulphate [HMIM]HSO4 and 1-methyl benzimidazolium hydrogen sulphate [HMBIM]HSO4 were synthesized. Their physicochemical properties were investigated using spectroscopic and thermal techniques, including UV-Vis, FT-IR, 1H NMR, 13C-NMR, mass spectrometry, and TGA. The ILs were immobilized on mesoporous silica gel and characterized by FT-IR spectroscopy, scanning electron microscopy, Brunauer–Emmett–Teller analysis, ammonia temperature-programmed desorption, and thermogravimetric analysis. [HMIM]HSO4@silica and [HMBIM]HSO4@silica have been successfully applied as promising replacements for conventional catalysts for alkane isomerization reactions at room temperature. Isomerization of n-heptane and n-octane was achieved with both catalysts. In addition to promoting the isomerization of n-heptane and n-octane (a quintessential reaction for petroleum refineries), these immobilized catalysts are non-hazardous and save energy.

Titanium dioxide (TiO2) thin films were deposited on fluorine tin oxide (FTO) coated glass substrate using spin-coating techniques and as-deposited films were sensitized with various dyes. A series of azo derivatives (2, 5a-b) having different structures were successfully prepared through the process of the azo coupling reaction. KAZO 6 was successfully synthesized by esterification of kojic acid obtained from sago waste with azo 5a. These azo dye were examined using density functional theory (DFT) and time-dependent density functional theory (TD-DFT) to obtain the vertical excitation, electron distribution, energy levels, band gap, and light-harvesting efficiency in the ground and excited state. The obtained values exhibited a good correlation with the experimental values. Efficiency enhancement was reported by the incorporation of KAZO 6 with curcumin extracted from turmeric. Spectroscopy and optical properties of synthesized dyes were characterized using CHNS elemental analysis, FTIR, 1H NMR, 13C NMR, and UV–Vis spectroscopies. KAZO 6 displayed an efficiency of 1.59% compared to azo derivatives 0.13–1.12%. The efficiency of KAZO 6 enhanced from 1.59 to 1.74% with the incorporation of turmeric dye.

In the present work, we have designed and synthesized two carbazole and phenothiazine donor moieties based metal-free organic sensitizers and their codes are WCBZ2 and WPTZ2 respectively. These sensitizers have been used for photocatalytic hydrogen (H2) evaluation application. The sensitizers exhibit good light absorption capability and electrochemical properties as well. For increasing water splitting capacity, incorporate platinum salt on TiO2 semiconductor photoanode was performed and compared hydrogen evolution with pure TiO2 photoanode. We have also studied the influence of the sensitizer's concentration and the effect of pH of the medium was explored. Using a theoretical measurement optimized both the synthesized dimer dyes structure geometry and the calculated their HOMO-LUMO energy level. Here also reported optimized pH and concentration of sensitizers in the reaction medium and found that the high hydrogen generation efficiency from water splitting is 138.3 μmol (348 TONs) by the WPTZ2 dye.

Here in design and synthesized new dimer organic metal free dyes based on various donor moieties along with dihydrothieno [3,4-b][1,4] dioxine and cynoacrylic acid are bridge and acceptor respectively. The influence of dye consist various donor moieties like phenothiazine (PTZ), phenoxazine (POZ) and carbazole (CBZ) studied carefully. The same donor and acceptor groups optical and electrochemical properties change when we change donor groups. The all dyes structure geometry optimization and energy levels (HOMO-LUMO) was calculated by density functional theory (DFT) with B3LYP/6-31G(d.p) basis set. It is evident from the studies that the strong electron withdrawing donor moiety based dye, POZ-102 exhibit highest short circuit current density (Jsc), open circuit voltage (Voc) and efficiency (η = 6.4%). The inside device electron recombination and electron lifetime was calculated by impedance spectroscopy and open circuit voltage decay techniques. In last the highest efficiency achieved POZ-102 dye based device checked long term stability up to 500hr under 100 mW/cm2 light illumination.

A novel series of coumarin based dyes were designed and synthesised with coumarin donor (D) moiety, various thiophene bridge (Th-π) unit and –CNCHCOOH acceptor (A). The dye sensitized solar cells' (DSSCs) performance, optical and electrochemical properties of coumarin dyes were examined systematically. Moreover, optimization calculations for the geometries of all the coumarin dyes with various Th-bridge units were studied by DFT (density functional theory). CDT-3 dye containing three Th- unit shows the highest short circuit current (Jsc = 15.14 mA/cm2) and efficiency is 6.02% under 1 sunlight (100 mW/cm2, AM1.5) illumination. The DSSCs devices with all three coumarin dyes exhibit good, long term stability up to 500hr.

We have developed a new series of pyridinium based dicationic ionic liquids (DCILs) having excellent thermal stability and good ionic conductivity. The effectiveness of these DCIL based electrolytes in photovoltaic devices and the effect of different anions (e.g. iodine, bromide, and thiocyanate) versus the device performance are studied by cyclic voltammetry (CV), current–voltage (I–V) characteristics and electrochemical impedance spectroscopy (EIS). The electrolyte 2PrSCN based device C exhibited the highest photo conversion efficiency (PCE) of 5.23% under 1 sun (100 mW cm−2) illumination of light. We have also analyzed the influence of various anions in metal-free dye-sensitized TiO2 and the DCIL interface using the EIS technique. Device C based on 2PrSCN shows excellent long-term stability, maintaining

The effect of co-absorbance on the performance of DSSC devices with a new design of dimer sensitizers possessing a 2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione (DPP) bridge and various donor groups (carbazole, diphenyl amine, indole) is reported in the present work. The co-absorbent (CDCA = chenodeoxycholic acid) was inserted into the sensitizers and the photovoltaic performance was studied. The co-absorbent had a significant effect on Jsc, Voc and the efficiency. Without incorporation of the co-absorbent, a higher efficiency of around 4.40% is exhibited (Jsc = 9.91 mA cm−2 and Voc = 0.678 V) by the R3 device, while after adding the co-absorbent, we have achieved an efficiency of around 4.44% (Jsc = 10.3 mA cm−2 and Voc = 0.693 V). Structure optimization and energy level calculations were carried out by density functional theory (DFT) with different donor substituents and DPP bridge based sensitizers. The co-absorbent and sensitizer based DSSCs were also characterised by impedance spectroscopy and incident photon to current conversion efficiency measurements.

Stimuli-responsive di-block copolymers viz. poly(N-isopropylacrylamide)m-block-poly(butyl-3-vinylimidazolium bromide)n [abbreviated as PNIPAMm-b-PBVIBn m = 50 and 100, n = 54 and 115] were synthesized using RAFT (Reversible addition−fragmentation chain-transfer) polymerization. Gel permeation chromatography (GPC) and nuclear magnetic resonance (1H NMR) spectroscopy were used to characterize the block copolymer. Turbidity data shows that the lower critical solution temperature (LCST) of PNIPAM is independent of the molecular weight. No LCST behavior was estimated for PBVIB58 in an aqueous media. The addition of 2.75 M NaCl brings LCST of PBVIB58 to room temperature. The cloud point temperature (CPT) of both the block copolymers increases with an increase in the degree of polymerization of PBVIB. Scattering techniques confirm the molecular state of all the homopolymers at 28 °C in the dissolved condition. With an increase in temperature and the presence of sodium chloride (NaCl), both the copolymers remain as aggregates with PNIPAM as a core and PBVIB as a shell. The reverse structure is formed via the addition of 10 mM sodium dodecyl sulfate (SDS) into PNIPAM100-b-PBVIB54 solution.

In the present work, hydroxy butyl methyl cellulose-based quasi-solid-state polymer gel electrolyte has been prepared by incorporating I−/I3 − couple in ethylene carbonate and propylene carbonate. This bare electrolyte’s properties have been investigated first time by additional doping of amino pyridine analogous moieties such as pyridin-4-amine, di(pyridin-4-yl)amine, and tri(pyridin-4-yl)amine moiety. Effect on ionic conductivity, triiodide diffusion, glass transition temperature, rheology, and photovoltaic performance in dye-sensitized solar cells (DSSC) was briefly evaluated. Addition of dopant creates amorphous loops in the gel matrix, and dopant has lone pair of electrons at the N of pyridile, which attracts the Li+ species of LiI making smooth and fast diffusion of triiodides. Tg and XRD characterizations were performed to prove the immense effect on physical properties. TPA-doped electrolyte shows 4.3 mS/cm conductivity and has explored 3.67% power conversion efficiency in DSSC with N719 sensitizer. This non-volatile type of electrolyte-based DSSCs performs efficiently up 600 h in one sun illumination.

The synthesis and spectroscopic characterization of task-specific ionic liquid (TSIL) and its surface active properties are depicted in this study. The detailed synthesis protocol for C n PyCl ( n = 4, 6, 8) along with C n PyDs are discussed. The physical properties of ILs including their solubility in various organic solvent are given. The synthesized ILs is characterized by 1 H NMR, IR, MS and thermal methods From the TGA analysis, it found that the stability is increases by replacing anion (Cl − ) by dodecylsulphate of ILs. The C n PyDs has very limited solubility in water, therefore they are making stable micelles and their geometry and size is determined by Small Angle Neutron Scattering (SANS) measurements. We have demonstrated that micellar behaviour of TSIL in water by SANS and surface tension measurements.

The interaction of ionic liquids (ILs) with non-ionic triblock copolymer, Pluronic® P123, in aqueous solutions has been investigated using Small Angle Neutron Scattering (SANS) measurements. The mi...

The interaction of ionic liquids (ILs) with non-ionic triblock copolymer, Pluronic® P123 in aqueous solutions has been investigated using DLS, surface tension, and viscosity measurements. The addition of ILs increased the Critical Micelle Concentration (CMC) of P123, which appears to be logistic. As the added IL enhances the solubility of PPO moiety (and PEO), which makes them to behave like a more hydrophilic block copolymer that would be micellized at high copolymer concentration. The DLS data is in good agreement to the results observed from surface tension measurements. Viscosity results show the propensity in micellar size reduction upon addition of ILs, and hence, intrinsic viscosity decreases as compared to pure P123 aqueous solution. The results are studied and discussed as a function of cationic head groups of N-octyl-pyridinium/imidazolium chloride based ILs.

Ionic liquids (ILs) have emerged as an environmentally friendly alternative to the volatile organic solvents. ILs which are made up of cationic and anionic components can be designed to possess a definite set of properties. In this context, the term “designer solvents” has been used to demonstrate the potential of these environment-friendly ILs in chemical reactions. Being designer solvents, they can be modulated to suit the reaction conditions, therefore earning the name “task specific ILs.” Since these liquids are able to dissolve several transition metal complexes, they have often been employed in recent times in several catalytic organic reactions to enhance reaction rates and selectivity. Though primarily used as solvents, they are now finding applications in various fields like catalysis, electrochemistry, spectroscopy, and material science to mention a few. ILs is capable to restrict many of the negative effects of the conventional organic solvents or other catalysts during catalytic reactions and have successfully been used in various catalytic areas affording high catalytic activity. The present review is aimed at exploring the structural characteristics, properties, preparation and applications of ILs in catalytic organic transformations.

Pluronics® and Tetronics® are used in industry for solubilizing various kinds of hydrophobic compounds since decades. In present study, moderately hydrophobic linear and star block copolymer viz. Pluronic® P104 and Tetronic® T1304 are employed for the solubilization of four polycyclic aromatic hydrocarbons (PAHs) viz. naphthalene (Np), anthracene (An), phenanthrene (Ph) and pyrene (Py). The aggregation behaviour of these block copolymers in an aqueous media has been investigated by cloud point (CP), viscometry, dynamic light scattering (DLS), and small angle neutron scattering (SANS) techniques. The aqueous solubilities of these PAHs are quite poor, hence their extractions from contaminated areas are difficult. Cloud point of block copolymers linearly decreases as a function of PAHs concentration and strongly depends on the structure of PAHs. The aqueous solutions of both block copolymers are Newtonian fluid. The solubilization of PAHs in these copolymeric micelles leads to increase in the viscosity of solution suggesting the growth of micelles. The effect of concentration and temperature on the size and shapes of micelles were evaluated from DLS and SANS studies. The study provides an alternative method for the remediation of PAHs using inexpensive commercially available block copolymers.

The efficiency in the catalytic performance of halogen free functionalized room-temperature Bronsted acidic ionic liquids (BAILs), having different acidities (due to the ILs containing zero, a single, and or a double –SO3H functional group), for the esterification of n-butanol with acetic acid under various reaction conditions was investigated. The synthesized BAILs have much weaker corrosiveness than that of H2SO4. The nature of both counter anion and cation as well as the presence of additional functional (–SO3H) groups influenced the behavior of the catalyst. Interestingly, the acidic character of the ILs facilitates the reaction under extremely mild conditions, with a short reaction time, and reduction in the side reactions; moreover, the liquid–liquid biphasic reaction mode leads to good yields. The physicochemical properties of these BAILs were characterized by a variety of different analytical and spectroscopic techniques, such as NMR, FT-IR, mass spectrometry, TGA, and UV-vis spectroscopy for the determination of Hammett acidity. In particular, IL-5 having the highest acidity demonstrated excellent catalytic activity for esterification. An additional advantage of BAILs is the simple procedure for the separation of product and catalyst, where the catalysts can be easily recycled without the loss of catalytic activities, making IL-5 an important alternative catalyst for a commercially viable esterification process.

Lepidolite is a kind of low-grade lithium ore (3.5–4.0% Li2O) which contains more than 22% Al2O3 and 8% K2O. Removal and utilization of the Al and K will be very important for the economic extraction of lithium from this ore. In this paper, a novel method is proposed to remove Al from the leaching solution of lepidolite by adding ammonium from (NH4)2SO4. The results indicate that adding NH4 + could remove more aluminum and have a smaller loss of lithium in comparison to adding K+ for removing aluminum in the leaching solution. The Al removal reached up to 80.44% at (K+ + NH4 +)/Al3+ molar ratio of 0.95, while the amount of Li+ (99.84%) still remained in the leaching solution. In addition, the phase equilibrium in the quaternary K2SO4-Al2(SO4)3-(NH4)2SO4-H2O system at 278.2 K was investigated to support the above conclusion. The results verify that the addition of ammonium could remove more Al3+ by easily forming potassium alum (KAl(SO4)2·12H2O) and ammonium alum (NH4Al(SO4)2·12H2O).

The non-ionic triblock copolymer, Pluronic® F127, has been selected to observe its interaction with ionic liquids (ILs) in aqueous solutions by using DLS, surface tension, and viscosity measurements. The Critical Micelle Concentration (CMC) of F127 increased with the addition of ILs, which appeared logical since it increases the solubility of PPO (and PEO) moiety, making it behaves more like a hydrophilic block copolymer that is micellized at a higher copolymer concentration. The results from DLS data showed good agreement with those obtained from the surface tension measurements. Upon the addition of ILs, the tendency in micellar size reduction was demonstrated by viscosity results, and therefore, intrinsic viscosity decreased compared to pure F127 in aqueous solution. The results were discussed as a function of alkyl chain length and anions of imidazolium based ILs.

The catalysts γ-alumina (GA, the reference catalyst) and Pt doped γ-alumina (PGA-s) were synthesized using a simple sol-gel technique, in which at first preparation of porous base (GA), then impregnation of platinum salt over the base and finally reduction of platinum in the surface of the support were done. These catalysts prepared in different mole ratios of Pt:Al as 2:1, 1:1 and 1:2 are named as PGA-1, PGA-2 and PGA-3 respectively. The isomerization of n-alkanes (n-hexane, n-heptane and n-octane) were investigated over the synthesized catalysts. The 2-methyl pentane (2-MP), 2,2-dimethyl pentane (2,2-DMP) and 2,3-dimethyl hexane (2,3-DMH) are the major products of respective isomerization of n-hexane, n-heptane and n-octane, besides a small amount of other branched isomers are also produced. The product distribution is comparable to that reported for Pt based other catalysts. The optimal mole ratios of Pt:Al is 1:1 (PGA-2) gives quite good catalytic activity for isomerization of n-alkane. Even through in reusability study, PGA-2 gives better performance than others. We have mainly focused on kinetic study, reaction mechanism behind isomerization and calculated the order of reactions and activation energies of the isomerization reactions in the present work. Keywords: Isomerization, n-alkanes, Catalyst, Reaction mechanism, Kinetics study, Activation energy

The isotropic micellar state of Pluronic P123 in the presence and absence of N-alkylpyridinium halide ionic liquids (ILs) is investigated using SANS, DLS, and (1)H NMR studies. The micellar structural parameters are obtained as a function of variation in alkyl chain length, anions, and concentrations of ILs by fitting the SANS scattering data with a model composed of core-shell form factor and a hard sphere structure factor of interaction. Addition of ILs decreases the micellar core, aggregation number, and hard sphere radius of P123 micelles. From quantitative analysis, we determined the amount of solvent (D2O + IL) present inside the core and the core-shell interface along with cationic head groups. This is further supported by monitoring interaction between ILs and polymer micelle using (1)H NMR spectroscopy. The results are discussed and explained as a function of concentration of C8PyCl, alkyl chain length, and anions of N-alkylpyridinium halides.

Effect of ionic liquids (ILs) viz. pyridinium, picolinium and imidazolium halide on the micellization and the structure of poly(ethylene oxide)–poly(propylene oxide)–poly(ethylene oxide) (PEO–PPO–PEO) triblock copolymer, F127 in aqueous solution has been studied by small angle neutron scattering (SANS) and dynamic light scattering (DLS) measurements. The interaction information between ILs and PEO/PPO has been explored by using 1H NMR and viscosity measurements. The micellar structural parameters are obtained as a function of variation in alkyl chain length, cationic head group and concentrations of ILs by fitting the SANS data with model composed of core–shell form factor and a hard sphere structure factor of interaction. Addition of ILs is found to decrease the micellar core radius, aggregation number and hard sphere radius of F127 micelles. The effect of concentration, chain length and head groups of ILs also have been studied.

Dynamic light scattering, cloud point (CP), and surface tension studies have been carried out to examine the influence of six (including two acetates, two alkoxyethanols, and two sugars) nonelectrolyte additives on two silicone surfactants based on poly (dimethyl siloxane)—graft—polyethers in aqueous solutions. The results indicate that the presence of alkoxyethanols induced the oblate ellipsoidal to spherical micellar transition, while sugars increase the size of the ellipsoidal micelles. The effect of cosolvent or additives on critical micelle concentration (CMC) and CP is discussed on the basis of water structure making and breaking effect. The thermodynamic and surface active parameters were calculated from the surface tension isotherm curves.

Catalytic isomerization of n-hexane to its corresponding branched liquid hydrocarbon isomers by three different ionic liquids (ILs) having general formula; [BmimCl·2AlCl3], [BPyCl·2AlCl3] and [Et3NHCl·2AlCl3] were investigated in the present work. Due to the optimum acidic nature of the ILs, the reaction moves through faint conditions in a liquid-liquid biphasic reaction mode, this confirms a minimum extent of unwanted cracking side-reactions. ILs showed good catalytic activity due to their appreciable Bronsted and Lewis acidity. The BmimCl·2AlCl3 and Et3NHCl·2AlCl3 show higher conversion of n-hexane compared to BPyCl·2AlCl3 under similar reaction condition. The selectivity of isomers is lower at higher conversion range. On increasing the reaction time and temperature, the conversion of n-hexane rises up, while the selectivity of i-alkanes and i-hexanes were reduced. The optimal reaction temperature, reaction time and IL/n-hexane ratio were 30 °C, 24 hand 1:1, respectively; the conversion of n-hexane is 25.7%, 11.52%, 36.3%, the selectivity to i-alkanes is 97.58%, 99.55%, 99.16%, and selectivity to i-hexane 87.28%, 70.10%, 95.86%, respectively.

Imidazolium-based metal and halogen-free Brönsted acidic ionic liquid (BAIL) (3,3′-(hexane-1,6-diyl)bis(2-methyl-1-(3-sulfopropyl)-1H-benzimidazolium) hydrogensulfate [HbMBIM-PS][HSO4] was synthesized. The physicochemical properties of this BAIL were investigated using a variety of different analytical and spectroscopic techniques such as 1H and13C-NMR, FT-IR, mass, UV–vis and TGA spectra. A porous silica matrix has been synthesized using BAIL and tetraethoxysilane (TEOS) as silica source by nonhydrolytic sol–gel method. The properties of IL confined silica gel matrix have been studied using FTIR, TGA, SEM, N2-sorption measurement (BET characterization for determining pore parameters), and NH3-TPD techniques. From the N2-sorption measurement, it has been found that BET surface area decreased while pore volume, average pore size and porosity decreased. The thermal stability of the IL has been found to increase upon confinement in silica gel matrix. The results suggested that IL had been successfully confined on silica gel. This IL confined silica gel catalyst is environment friendly and useful for alkane isomerization and esterification reactions.

Marine bis-indole alkaloids comprise a large and increasingly growing class of secondary metabolites, and continue to deliver a great variety of structural templates for diverse biological targets. The alkaloids derived from marine resources play a crucial role in medicinal chemistry and as chemical agents. In particular, bis-indole alkaloid caulerpin which has been isolated from marine green algae Caulerpa and a red algae Chondria armata at various places around the world, was tested for several therapeutic potentials such as anti-diabetic, antinociceptive, anti-inflammatory, anti-tumor, anti- larvicidal, anti-herpes, anti-tubercular, anti-microbial and immunostimulating activities as well as a means of other chemical agents. Herein, we summarized the discovery and isolation of caulerpin, and its potential medicinal and chemical applications in chronological order with various aspects. Additionally, synthesis of caulerpin and its functional analogues have also been reviewed.

The preparation of ordered polymer gels from the amphiphilic block copolymers, Pluronic® F77, P123 and polyethylene glycol in the presence of ionic liquid, iodine and organic additives is presented. At 35%(w/w) concentration these copolymers (F77 and P123) self-assembled into cubic liquid crystalline phase in aqueous solution and characterized by using SAXS and AFM measurements. The effects of micellar aggregation formed by polymers on the ionic transport and triiodide diffusion have been studied by electrochemistry and SANS experiments. The ionic migration or triiodide diffusion through these polymer gels is found to be affected by the PEO/PPO content in the polymer backbone. These gels were successfully employed as an electrolyte in a dye sensitized solar cell. A remarkable solar to electricity conversion efficiency and good stability was obtained using Pluronic® F77 based gel, which is attributed to its thermoreversible sol to gel transition.

Spherical silver nanoparticles (AgNPs) with size ∼20 nm have been synthesized from an aqueous AgNO3 solution using the amphiphilic block copolymer, Pluronic P123 (EO20–PO70–EO20), under ambient conditions without the use of any other reducing agents. The size of the AgNPs was highly dependent on the size and geometry of the micelles of the block copolymer. The AgNPs synthesized from the block copolymer mediated synthesis were characterized by UV-Vis spectroscopy, Transmission Electron Microscopy (TEM) and Dynamic Light Scattering (DLS). The addition of an ionic liquid (IL), N-alkyl pyridinium dodecyl sulphate, CnPyDs, where n = 4, 6, 8, prepared by modifying N-alkyl pyridinium chloride with an anionic surfactant, sodium dodecyl sulphate (SDS), induced a sphere-to-ribbon (cylindrical) transition of the AgNPs. We observed that the presence of ILs reduces the equilibrium time as well as acting as a shape directing agent. The micelles of P123 and ILs in aqueous solution were characterized by Small Angle Neutron Scattering (SANS) and DLS methods. The size and shape of the AgNPs correlate with the geometry of micelles of the amphiphilic block copolymer and ILs in aqueous solution.