M.I. Abdul Mutalib

Dissolution and Delignification of Bamboo Biomass Using Amino Acid-Based Ionic Liquid

In the present work, the dissolution of bamboo biomass was tested using a number of ionic liquids synthesized in laboratory. It was observed that one of the synthesized amino acid-based ionic liquids, namely 1-ethyl-3-methylimidazolium glycinate, was capable of dissolving the biomass completely. The dissolved biomass was then regenerated using a reconstitute solvent (acetone/water) and was characterized using Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy. The results were compared to preconditioned bamboo biomass. The regenerated biomass was found to have a more homogenous macrostructure, which indicates that the crystalline form and structure of its cellulose has changed from type Ι to type ΙΙ during the dissolution and regeneration process.

Development of a novel mathematical model using a group contribution method for prediction of ionic liquid toxicities

A new mathematical model has been developed that expresses the toxicities (EC₅₀ values) of a wide variety of ionic liquids (ILs) towards the freshwater flea Daphnia magna by means of a quantitative structure-activity relationship (QSAR). The data were analyzed using summed contributions from the cations, their alkyl substituents and anions. The model employed multiple linear regression analysis with polynomial model using the MATLAB software. The model predicted IL toxicities with R²=0.974 and standard error of estimate of 0.028. This model affords a practical, cost-effective and convenient alternative to experimental ecotoxicological assessment of many ILs.

Effect of imidazolium-based ionic liquids on bacterial growth inhibition investigated via experimental and QSAR modelling studies

Tuning the characteristics of solvents to fit industrial requirements has currently become a major interest in both academic and industrial communities, notably in the field of room temperature ionic liquids (RTILs), which are considered one of the most promising green alternatives to molecular organic solvents. In this work, several sets of imidazolium-based ionic liquids were synthesized, and their toxicities were assessed towards four human pathogens bacteria to investigate how tunability can affect this characteristic. Additionally, the toxicity of particular RTILs bearing an amino acid anion was introduced in this work. EC50 values (50% effective concentration) were established, and significant variations were observed; although all studied ILs displayed an imidazolium moiety, the toxicity values were found to vary between 0.05 mM for the most toxic to 85.57 mM for the least toxic. Linear quantitative structure activity relationship models were then developed using the charge density distribution (σ-profiles) as molecular descriptors, which can yield accuracies as high as 95%.

Extraction and characterization of lignin from oil palm biomass via ionic liquid dissolution and non-toxic aluminium potassium sulfate dodecahydrate precipitation processes.

The objective of this study is to extract and characterize lignin from oil palm biomass (OPB) by dissolution in 1-butyl-3-methylimidazolium chloride ([bmim][Cl]), followed by the lignin extraction through the CO2 gas purging prior to addition of aluminum potassium sulfate dodecahydrate (AlK(SO4)2 · 12H2O). The lignin yield, Y(L) (%wt.) was found to be dependent of the types of OPB observed for all precipitation methods used. The lignin recovery, RL (%wt.) obtained from CO2-AlK(SO4)2 · 12H2O precipitation was, however dependent on the types of OPB, which contradicted to that of the acidified H2SO4 and HCl solutions of pH 0.7 and 2 precipitations. Only about 54% of lignin was recovered from the OPB. The FTIR results indicate that the monodispersed lignin was successfully extracted from the OPT, OPF and OPEFB having a molecular weight (MW) of 1331, 1263 and 1473 g/mol, and degradation temperature of 215, 207.5 and 272 °C, respectively.

Extraction and Recovery of Naphthenic Acid from Acidic Oil Using Supported Ionic Liquid Phases (SILPs)

Abstract In this study, functionalized silica supported ionic liquids phases (SILPs) were synthesized and characterized using Fourier Transform infrared (FTIR) spectroscopy, CHNS elemental analysis, thermo gravimetric analysis (TGA) and scanning electron microscopy (SEM). The adsorption of model naphthenic acid such as hexanoic acid, benzoic acid and commercial naphthenic acid from dodecane/kerosene was also investigated. The silica supported ionic liquids are good adsorbent for the removal of naphthenic acid from highly acidic model oil. The regeneration of supported ionic liquid phases as well as recovery of naphthenic acids from the supported ionic liquid phases (SILPs) was investigated.

Development of QSAR model to predict the ecotoxicity of Vibrio fischeri using COSMO-RS descriptors

Ionic liquids (ILs) are class of solvent whose properties can be modified and tuned to meet industrial requirements. However, a high number of potentially available cations and anions leads to an even increasing members of newly-synthesized ionic liquids, adding to the complexity of understanding on their impact on aquatic organisms. Quantitative structure activity∖property relationship (QSAR∖QSPR) technique has been proven to be a useful method for toxicity prediction. In this work,σ-profile descriptors were used to build linear and non-linear QSAR models to predict the ecotoxicities of a wide variety of ILs towards bioluminescent bacterium Vibrio fischeri. Linear model was constructed using five descriptors resulting in high accuracy prediction of 0.906. The model performance and stability were ascertained using k-fold cross validation method. The selected descriptors set from the linear model was then used in multilayer perceptron (MLP) technique to develop the non-linear model, the accuracy of the model was further enhanced achieving high correlation coefficient with the lowest value being 0.961 with the highest mean square error of 0.157.

Modeling of solubility of CO2 in 1-butylpyridinium bis(trifluoromethylsulfonyl)imide ionic liquid using UNIFAC

The solubility of CO2 in 1-butylpyridinium bis(trifluoromethylsulfonyl)imide [C4py][Tf2N] ionic liquid has been determined using Magnetic Suspension Balance instrument at 298.15 K and in the pressures up to about 27 bar. A group contribution method, namely UNIFAC has been used to fit the experimental data. The interaction parameters of the model were estimated. The predicted CO2 solubility data by the model shows good agreement with the experimental data.

Study of the antimicrobial activity of cyclic cation-based ionic liquids via experimental and group contribution QSAR model

Over the past decades, Ionic liquids (ILs) have gained considerable attention from the scientific community in reason of their versatility and performance in many fields. However, they nowadays remain mainly for laboratory scale use. The main barrier hampering their use in a larger scale is their questionable ecological toxicity. This study investigated the effect of hydrophobic and hydrophilic cyclic cation-based ILs against four pathogenic bacteria that infect humans. For that, cations, either of aromatic character (imidazolium or pyridinium) or of non-aromatic nature, (pyrrolidinium or piperidinium), were selected with different alkyl chain lengths and combined with both hydrophilic and hydrophobic anionic moieties. The results clearly demonstrated that introducing of hydrophobic anion namely bis((trifluoromethyl)sulfonyl)amide, [NTF2] and the elongation of the cations substitutions dramatically affect ILs toxicity behaviour. The established toxicity data [50% effective concentration (EC50)] along with similar endpoint collected from previous work against Aeromonas hydrophila were combined to developed quantitative structure-activity relationship (QSAR) model for toxicity prediction. The model was developed and validated in the light of Organization for Economic Co-operation and Development (OECD) guidelines strategy, producing good correlation coefficient R2 of 0.904 and small mean square error (MSE) of 0.095. The reliability of the QSAR model was further determined using k-fold cross validation.

Desulfurization of oxidized diesel using ionic liquids

The extraction of oxidized sulfur compounds from diesel were carried out using ten types of ionic liquids consisting of different cation and anion i.e. 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazoium thiocyanate, 1-butyl-3-methylimidazoium dicyanamide, 1-butyl-3-methylimidazolium trifluoromethanesulfonate, 1-butyl-3-methylimidazoliumhexafluorophosphate, 1-hexyl-3-methylimidazolium trifluoromethanesulfonate, trioctylmethylammonium chloride, 1-propionitrile-3-butylimidazolium thiocyanate, 1-propionitrile-3-butylimidazolium dicyanamide and 1-butyl-6-methylquinolinium dicyanamide. The oxidation of diesel was successfully done using phosphotungstic acid as the catalyst, hydrogen peroxide (H2O2) as the oxidant and trioctylmethylammonium chloride as the phase transfer agent. The oxidation of diesel changes the sulfur compounds into sulfone which increases its polarity and enhances the ionic liquids extraction performance. Result showed that ionic liquid [C4mquin][N(CN)2] performed the ...

Experimental solubility of CO 2 and CH 4 in imidazolium based ionic liquid; [C 6 mim][BF 4 ] at high pressures

The solubility*of carbon dioxide (CO<inf>2</inf>) in fresh and recycled ionic liquid (IL); 1-hexyl-3-methyl imidazolium tetrafluoroborate [C<inf>6</inf>mim][BF<inf>4</inf>] was experimentally measured at three different temperatures i.e., 303.15 K, 318.15 K, 333.15 K and pressures up to 60 bar. The solubility of CO<inf>2</inf> and Methane (CH<inf>4</inf>) in fresh IL; [C<inf>6</inf>mim][BF<inf>4</inf>] was also measured using binary mixtures of CO<inf>2</inf> and CH<inf>4</inf> i.e., 60/40 (B<inf>64</inf>) and 40/60 (B<inf>46</inf>) volume percent at temperatures (303.15 K, 318.15 K, 333.15 K) and pressures up to 60 bar. The solubility measurements for both gases were performed in a specifically designed high pressure miniature gas solubility cell. The solubility of CO<inf>2</inf> and CH<inf>4</inf> in the studied IL increased almost linearly with an increase in pressure and decreased with an increase in temperature and no significant difference was observed for the amount of CO<inf>2</inf> absorbed in fresh and recycled IL at the studied range of operating conditions. It was observed that the presence of CH<inf>4</inf> significantly reduced the solubility of CO<inf>2</inf> in the studied IL.