| 1. |
- Khan, Amir Sada, et al.
(author)
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Chapter 1 - Conversion of biomass to chemicals using ionic liquids
- 2020
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In: Green Sustainable Process for Chemical and Environmental Engineering and Science. - : Elsevier. ; , s. 1-30
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Book chapter (other academic/artistic)abstract
- From the conversion of lignocellulosic biomass to platform chemicals using ionic liquids (ILs), it was concluded that ILs have dual functions and can be used as catalyst and solvent for the synthesis of 5-hydroxymethylfurfural (5-HMF) and levulinic acid (LA) from lignocellulosic biomass. The conversion of lignocellulosic biomass to chemicals depends upon the nature of feedstocks and structure of ILs. The yield of 5-HMF and LA from fructose and glucose is higher than cellulose and lignocellulose. Among the various available ILs, the acidic ionic liquids (AILs) such as [C3SO3Hmim][HSO4], [C4SO3Hmim][HSO4], [C3SO3Hmim][CH3SO3], [C3SO3Hmim][Cl], [C3SO3Hmim][CF3SO3], and [C3SO3HPy][HSO4] showed better yield of 5-HMF and LA. The imidazolium-based ILs that contain acidic functional group such HSO4 and Cl anion resulted in higher yield of LA and 5-5-HMF, respectively. Therefore it is essential to synthesize such ILs that have acidic functional group in their structure for the direct conversion of cellulose and lignocellulosic biomass to 5-HMF and LA.
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| 2. |
- Khan, Amir Sada, et al.
(author)
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Efficient Conversion of Lignocellulosic Biomass to Levulinic Acid Using Acidic Ionic Liquids
- 2018
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In: Carbohydrate Polymers. - : Elsevier. - 0144-8617 .- 1879-1344. ; 181, s. 208-214
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Journal article (peer-reviewed)abstract
- In the present research work, dicationic ionic liquids, containing 1,1-Bis(3-methylimidazolium-1-yl) butylene ([C4(Mim)2]) cation with counter anions [(2HSO4)(H2SO4)0], [(2HSO4)(H2SO4)2] and [(2HSO4)(H2SO4)4] were synthesised. ILs structures were confirmed using 1H NMR spectroscopy. Thermal stability, Hammett acidity, density and viscosity of ILs were determined. Various types of lignocellulosic biomass such as rubber wood, palm oil frond, bamboo and rice husk were converted into LA. Among the synthesized ionic liquids, [C4(Mim)2][(2HSO4)(H2SO4)4] showed higher % yield of LA up to 47.52 from bamboo biomass at 100 °C for 60 min, which is the better yield at low temperature and short time compared to previous reports. Surface morphology, surface functional groups and thermal stability of bamboo before and after conversion into LA were studied using SEM, FTIR and TGA analysis, respectively. This one-pot production of levulinic acid from agro-waste will open new opportunity for the conversion of sustainable biomass resources into valuable chemicals.
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| 3. |
- Naz, Sadia, et al.
(author)
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One-Pot Deconstruction and Conversion of Lignocellulose Into Reducing Sugars by Pyridinium-Based Ionic Liquid–Metal Salt System
- 2020
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In: Frontiers in Chemistry. - : Frontiers Media S.A.. - 2296-2646. ; 8
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Journal article (peer-reviewed)abstract
- Constantly decreasing fossil resources and exceeding energy demands are the most alarming concerns now-a-days. The only way out is to develop efficient, safe and economic biomass processing protocols that can lead towards biofuels and fine chemicals. This research is one of such consequences involving the deconstruction and conversion of wheat straw carbohydrate constituents into reducing sugars via one-pot reaction promoted by Lewis acidic pyridinium based ionic liquids (PyILs) mixed with different metal salts (MCl). Various parameters such as the type of metal salt, loading amount of metal salt, time, temperature, particle size of biomass and water content which affect the deconstruction of wheat straw have been evaluated and optimized. Among the studied IL and metal salt systems, the best results were obtained with [BMPy]+CoCl3‒. The dinitrosalicylic acid (DNS) assay was used to determine the percentage of total reducing sugars (TRS) generated during treatment of wheat straw. The deconstructed wheat straw was characterized with various analytical tools i.e. FTIR, SEM and XRD analyses. The ionic liquid‒metal salt system was recycled for subsequent treatment of wheat straw. Statistical parameters were calculated from analysis of variance (ANOVA) at 0.05 level of confidence.
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| 4. |
- Sarwono, Ariyanti, et al.
(author)
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Alkyd paint removal : Ionic liquid vs volatile organic compound (VOC)
- 2018
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In: Progress in organic coatings. - : Elsevier. - 0300-9440 .- 1873-331X. ; 122, s. 79-87
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Journal article (peer-reviewed)abstract
- The drive towards safer technology in removing paint from substrate requires switching from hazardous volatile organic compounds to greener alternative solvents. Ionic liquids (ILs) have been considered as relatively green solvents and employed in many applications. This study focusses on investigation of ILs as alternative green solvents for paint removal. In this regard, five imdazolium based ILs were studied for alkyd paint removal on coated wooden substrate. The effect of various anions such as dicyanamide [DCA], bis (trifluoromethanesulfonyl) imide [NTf2], hydrogen sulphate [HSO4], acetate [OAc] and chloride [Cl] was investigated. For benchmarking and comparison, three volatile organic solvents such as toluene, acetonitrile, and ethanol were used. Microscopic images showed that [DCA] anion gave significant impact on alkyd removal. In addition, [Bmim][DCA] gave highest swelling percentage of 23% whereas the other ILs did not show significant swelling. Viscosity, anion size and alkyd paint-IL interactions played important roles in removal efficacy. The prolonged immersion time in [Bmim][DCA] decreased the pull off adhesion strength up to 83.3% and consecutively promoted paint detachment from substrate. Similar infrared pattern of bare wooden stick and [Bmim][DCA] treated coated wooden stick indicates significant removal of paint by IL. The experimental results demonstrate promising application of IL as a green solvent for paint removal.
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| 5. |
- Sarwono, Ariyanti, et al.
(author)
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Optimization of ionic liquid assisted sugar conversion and nanofiltration membrane separation for 5-hydroxymethylfurfural
- 2019
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In: Journal of Industrial and Engineering Chemistry. - : Elsevier. - 1226-086X .- 1876-794X. ; 69, s. 171-178
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Journal article (peer-reviewed)abstract
- This paper provides complete loop of ionic liquid (IL) assisted glucose conversion to 5-hydroxymethylfurfural (HMF), nanofiltration membrane (NF) based separation and recyclability. The optimum HMF yield of 65.6% was obtained with 8wt.% catalyst loading at 125°C reaction temperature in 120min reaction time. Ea for conversion was found to be 120kJ/mol. NF was adopted first time to separate IL and HMF. The percentage of recovered HMF using NF for 1st, 2nd and 3rd batches are 94.87, 84.35 and 71.65 respectively. The structures of regenerated IL and HMF, obtained from NF and liquid–liquid extraction, were confirmed by NMR.
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| 7. |
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| 8. |
- Shahid, Robina, et al.
(author)
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Synthesis, COSMO-RS analysis and optical properties of surface modified ZnS quantum dots using ionic liquids
- 2015
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In: Journal of Physics and Chemistry of Solids. - : Elsevier BV. - 0022-3697 .- 1879-2553. ; 85, s. 34-38
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Journal article (peer-reviewed)abstract
- Zinc sulfide (ZnS) quantum dots (QDs) were synthesized using the microwave assisted ionic liquid (MAIL) route. Three ionic liquids (ILs), namely, 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF4]), trihexyl(tetradecyl) phosphonium bis(trifluoromethanesulfonyl) amide ([P-6,P-6,P-6,P-14][TSFA]) and trihexyl (tetradecyl) phosphonium chloride ([P-6,P-6,P-6,P-14][Cl]) were used in this study. The size and structure of the QDs were characterized by high-resolution transmission electron microscopy (HR-TEM) and selected area electron diffraction (SAED) pattern, respectively. The synthesized QDs were of wurtzite crystalline structure with size less than 5 nm. The QDs were more uniformly distributed while using the phosponium based ILs as a reaction medium during synthesis. The optical properties were investigated by UV-vis absorption and photoluminescence (PL) emission spectroscopy. The optical properties of QDs showed the quantum confinement effect in their absorption and the effect of cation and anion structural moiety was observed on their bandedge emission. The QDs emission intensity was measured higher for [P-6,P-6,P-6,P-14][Cl] due to their better dispersion as well as high charge density of Cl anion. The capability of the ILs in stabilizing the QDs was interpreted by density functional theory (DFT) computations. The obtained results are in good agreement with the theoretical prediction.
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