Solubility Parameters Research Articles

Solid-liquid equilibrium of forchlorfenuron in four binary solvents: Experiments, hansen solubility parameter and molecular simulation

In this research, the solubility of forchlorfenuron in 4 binary solvent systems {(methanol, ethanol, n-propanol and acetone) + water} was determined at certain experimental conditions (pressure of 101.3 kPa, temperature of 278.15 K-323.15 K) using laser dynamic monitoring method. Five thermodynamic models were applied to correlate and analyze the experimentally measured data. The modified Apelblat model has the lowest value of ARD (100ARD = 2.046 %) indicates that it fits best. The apparent thermodynamic properties during the dissolution process of forchlorfenuron in the four mixed solvent systems were explored using Van't Hoff equation. The effect of solvent properties on the dissolution was explored by calculating Hansen solubility parameters. For further understanding the solubility behavior on the molecular scale, molecular electrostatic potential analysis and Hirshfeld surface analysis were conducted to visualize the molecular surface charge distribution and predict the contact behavior between forchlorfenuron and solvent. Finally, the influence of intermolecular interactions between solute and solvent on solubility behavior was explored using radial distribution function analysis based on molecular dynamics simulations. And the results show the stronger intermolecular force corresponds to the larger solubility.

Compatibility of PCM modified asphalt based on naphthenic oil modification: A multiscale study

In this study, the compatibility of phase change material(PCM) in asphalt was investigated using several methods. Initially, solubility parameters, radial distribution functions, and relative concentrations of PCM modified asphalt were examined through molecular simulations to explore its compatibility. Subsequently, the phase structures of different PCM modified asphalt were analyzed using fluorescence microscopy experiments on both upper and lower samples. Finally, the compatibility differences among PCM modified asphalt samples with varying naphthenic oil contents were evaluated through softening point and Brookfield viscosity tests. The results indicate that higher naphthenic oil content in encapsulated PCM leads to closer solubility parameter alignment with the base asphalt. At a naphthenic oil content of 50% in encapsulated PCM, significant interactions occur between PCM and asphalt components. The concentration distribution curve of PCM molecules in the asphalt approaches 1.0, indicating excellent compatibility between encapsulated PCM and asphalt. Overall, the results from fluorescence microscopy and conventional tests are consistent with simulation outcomes. The only discrepancy observed is that conventional experimental results for the PCM-60% sample slightly outperform those for the PCM-50% sample.

Molecular dynamics simulations of the solubility of chitosan grafted polyacrylamide and its adsorption mechanism with kaolinite: Impact of length and distribution of branched‐chain

AbstractGraft modification can effectively improve the flocculation performance of chitosan. In this work, molecular dynamics simulations were employed to investigate the water solubility of chitosan‐grafted polyacrylamide (CTS‐g‐PAM) and its adsorption mechanism with kaolinite, focusing on the effects of branched‐chain length and distribution. The solubility parameters obtained from the simulations align better with those calculated using the group contribution method. The radius of gyration (Rg), solvation free energy (∆GSFE), mean square displacement and diffusion coefficient were utilized to analyze changes in solubility of these CTS‐g‐PAM in aqueous solution. The adsorption interaction between CTS‐g‐PAM and kaolinite was investigated using interaction energy and diffusion coefficients. The water solubility of CTS‐g‐PAM initially increased, followed by a subsequent decrease as the length of branched‐chain increased along with a decrease in their number. Similarly, the adsorption interaction between CTS‐g‐PAM and kaolinite increased firstly followed by a decrease with increasing branched‐chain length. The magnitude of interaction energy with kaolinite (0 0 1) followed the order of CA10‐12 (−826.227 kcal/mol) >CA8‐15 (−744.583 kcal/mol) >CA6‐20 (−637.366 kcal/mol) >CA12‐10 (−598.109 kcal/mol). These trends align with the findings of flocculation tests. Our work provides a theoretical basis for designing chitosan‐based flocculants with enhanced water solubility and improved flocculation efficiency.

Characteristics and Challenges of Poly(ethylene-co-vinyl acetate) Solution Electrospinning.

Poly(ethylene-co-vinyl acetate) (PEVA) is a versatile elastic, durable, and biocompatible copolymer, which can be processed by melt extrusion or solvent casting, while electrospinning has been reported as challenging. Here, a spinnability window should be identified using a total of 10 different PEVA materials with increasing vinyl acetate content (∼12-40 wt %) and molecular weights (∼60-130 kDa). Based on the solubility predictions by calculating Hansen solubility parameters, candidate solvents were experimentally evaluated. Spinning experiments with systematic alteration of solution composition and processing parameters revealed the causes of material deposition at the spraying nozzle and multijet spinning characteristics. By introducing a spinnability score that accounts for product characteristics and reproducibility, the spinnability of PEVA could be rationalized. Overall, it was demonstrated that PEVA solutions with an apparent viscosity of 920-3500 mPa·s can be spun to bead-free fibers of ∼10 μm. This size may allow suspension electrospinning of composite fibers in the future.

Solvent Replacement Strategies for Processing Pharmaceuticals and Bio-Related Compounds—A Review

An overview of solvent replacement strategies shows that there is great progress in green chemistry for replacing hazardous di-polar aprotic solvents, such as N,N-dimethylformamide (DMF), 1-methyl-2-pyrrolidinone (NMP), and 1,4-dioxane (DI), used in processing active industrial ingredients (APIs). In synthetic chemistry, alcohols, carbonates, ethers, eucalyptol, glycols, furans, ketones, cycloalkanones, lactones, pyrrolidinone or solvent mixtures, 2-methyl tetrahydrofuran in methanol, HCl in cyclopentyl methyl ether, or trifluoroacetic acid in propylene carbonate or surfactant water (no organic solvents) are suggested replacement solvents. For the replacement of dichloromethane (DCM) used in chromatography, ethyl acetate ethanol or 2-propanol in heptanes, with or without acetic acid or ammonium hydroxide additives, are suggested, along with methanol acetic acid in ethyl acetate or methyl tert-butyl ether, ethyl acetate in ethanol in cyclohexane, CO2-ethyl acetate, CO2-methanol, CO2-acetone, and CO2-isopropanol. Supercritical CO2 (scCO2) can be used to replace many organic solvents used in processing materials from natural sources. Vegetable, drupe, legume, and seed oils used as co-extractants (mixed with substrate before extraction) can be used to replace the typical organic co-solvents (ethanol, acetone) used in scCO2 extraction. Mixed solvents consisting of a hydrogen bond donor (HBD) solvent and a hydrogen bond acceptor (HBA) are not addressed in GSK or CHEM21 solvent replacement guides. Published data for 100 water-soluble and water-insoluble APIs in mono-solvents show polarity ranges appropriate for the processing of APIs with mixed solvents. When water is used, possible HBA candidate solvents are acetone, acetic acid, acetonitrile, ethanol, methanol, 2-methyl tetrahydrofuran, 2,2,5,5-tetramethyloxolane, dimethylisosorbide, Cyrene, Cygnet 0.0, or diformylxylose. When alcohol is used, possible HBA candidates are cyclopentanone, esters, lactone, eucalytol, MeSesamol, or diformylxylose. HBA—HBA mixed solvents, such as Cyrene—Cygnet 0.0, could provide interesting new combinations. Solubility parameters, Reichardt polarity, Kamlet—Taft parameters, and linear solvation energy relationships provide practical ways for identifying mixed solvents applicable to API systems.

Effects of solvent composition on agglomerate structure in catalyst ink for polymer electrolyte fuel cells

The solvent composition of the catalyst ink profoundly impacts both the porous structure and the efficiency of the mass-production process of the catalyst layer for polymer electrolyte fuel cells. However, the underlying mechanism remains far from elucidated. Here, we present the size of aggregate and the fractal dimension of the agglomerate structure as determined by ultra-small X-ray scattering (USAXS) of the catalyst inks with varied solvent composition. By examining the correlations between the structural properties provided by USAXS, rheological properties, and the quantity of ionomer adsorbed on the Pt/C, we elucidate the solvent's influence on the agglomerate structure. In highly polar solvents, akin to water, a considerable number of amphiphilic ionomers adsorb to the Pt/C particles, resulting in the formation of dispersed Pt/C aggregate particles approximately 200 nm in size that cannot be subdivided further into smaller particles even with the use of a homogenizer. As the polarity diminishes with the addition of alcohol content, ionomers desorb, and the affinity between the aggregates and the solvent decreases, leading to the evolution of agglomerates. The observed solvent effect can be rationally characterized by one of Hansen's solubility parameters, which specifies the polar interaction.

Study on the liquid–liquid phase separation phenomenon of iohexol in a binary mixed solvent of methanol and n-butanol: Thermodynamic behavior and molecular dynamics calculation

The impact of oiling-out on the control of the crystallization purification process during iohexol crystallization is significant. Thus, the solubility of iohexol and its oiling-out behavior in a binary solvent mixture of methanol and n-butanol was investigated in this study. The solubility was determined using the equilibrium method at temperatures ranging from 273.15 K to 303.15 K under atmospheric pressure, revealing that solubility increases with temperature and methanol concentration. Four models were employed to model the solubility data, with the CNIBS/R-K model demonstrating the highest correlation. The van't Hoff equation was utilized to calculate the thermodynamic properties, the result indicating that enthalpy predominates in the dissolution process. Furthermore, ternary phase diagrams were constructed to elucidate the nucleation mechanism of iohexol, identifying nucleation sites and performing kinetic simulations from a molecular perspective. These analyses indicated that lower temperatures are favor the control of oiling-out phenomena. The nucleation of iohexol is characterized by a two-step mechanism, initiating with liquid–liquid separation, followed by nucleation and crystal growth. Solubility parameters, derived using Materials Studio, suggest enhanced interactions between iohexol and methanol, which is also corroborated by the solvation energy data from Gaussian software. This interaction explains the tendency of iohexol to oiling out in mixed solvents. Radial distribution function (RDF) analysis illustrates that methanol-iohexol interactions intensify prior to oiling-out, reach a peak during oiling-out, and diminish after nucleation due to desolvation. The occurrence of oiling-out can lead to challenges such as diminished product quality, reduced yields, and difficulties in reprocessing. Therefore, understanding the mechanism of oiling-out is fundamental to addressing these issues, rendering these insights invaluable for the study of crystallization processes and oiling out phenomena in other small organic molecules.

Green solvent selection and extractin protocol for selective recovery of anti-diabetic components from T. crispa

This study systematically explores a green extraction process of T. crispa stems to selectively isolate therapeutic compounds, borapetoside C (BPC) and magnoflorine (MGF), recognized for their anti-diabetic properties. In agreement with Hansen solubility parameters prediction, H2O and EtOH were found to be suitable solvents for extraction of BPC and MGF, respectively, resulting in 33 % and 45 % extractabilities after 60 min. Further investigations demonstrated considerable increase in BPC extractability using 20 % EtOH:H2O mixture at 40 °C, with complete extraction achieved after 60 min. While for MGF, pure-EtOH at 40 °C, was the most suitable solvent, showing the highest selectivity and complete extraction after 100 min. The BPC-rich extract from 20 % EtOH:H2O exhibited higher anti-diabatic activity (IC50 = 0.63 ± 0.03 and 0.72 ± 0.04 mg/mL, respectively, for α-glucosidase and α-amylase enzymes inhibition activity), and considerably lower cytotoxicity to L6 and HepG2 cells, with IC50 = 0.26 ± 0.16 and 0.24 ± 0.02 mg/mL, respectively, compared with the MGF-rich extract obtained with pure-EtOH. Based on these results, a sequential extraction scheme was proposed involving initial pure-EtOH extraction to selectively and completely remove MGF, followed by extraction with a 20 % EtOH:H2O mixture to recover the remaining BPC, which was approximately 80 % of the BPC originally present. The obtained MGF-free BPC-rich extract showed significantly lower cytotoxicity (IC50 = 0.31 ± 0.06 mg/mL against L6 cell) and higher enzyme inhibition activities (IC50 = 0.53 ± 0.32 and 0.52 ± 0.02 mg/mL for α-glucosidase and α-glucosidase enzymes inhibition activity), comparable to acarbose (IC50 = 0.43 ± 0.02 and 0.83 ± 0.03 mg/mL for α-glucosidase and α-glucosidase enzymes inhibition activity), the result that potentially leads to the development of a promising industrial process to harness T. crispa for diabetes prevention and treatment.

Conventional and Green Rubber Plasticizers Classified through Nile Red [E(NR)] and Reichardt’s Polarity Scale [ET(30)

After a survey on polymer plasticization theories and conventional criteria to evaluate polymer–plasticizer compatibility through the solubility parameter, an attempt to create a polymer–plasticizer polarity scale through solvatochromic dyes has been made. Since Reichardt’s ET(30) dye is insoluble in rubber hydrocarbon polymers like polyisoprene, polybutadiene and styrene–butadiene copolymers and is not useful for the evaluation of the hydrocarbons and ester plasticizers, the Nile Red solvatochromic dye was instead used extensively and successfully for this class of compounds. A total of 53 different compounds were evaluated with the Nile Red dye and wherever possible also with Reichardt’s ET(33) dye. A very good correlation was then found between the Nile Red scale E(NR) and Reichardt’s ET(30) scale for this class of compounds focusing on diene rubbers and their typical hydrocarbons and new ester plasticizers. Furthermore, the E(NR) scale also shows a reasonable correlation with the total solubility parameter calculated according to the Van Krevelen method. Based on the above results, some conclusion was made about the compatibility between the diene rubbers and the conventional plasticizers, as well as a new and green plasticizer proposed for the rubber compounds.

Computational modelling of extrusion process temperatures on the interactions between black soldier fly larvae protein and corn flour starch

Insects such as the black soldier fly (BSF) are recently being studied as food sources to address concerns about how to meet the food demand of the growing world population, as conventional production lines for meat proteins are currently unsustainable sources. Studies have been conducted evaluating the use of insect proteins to produce extruded foods such as expanded snacks and meat analogues. However, this field of study is still quite new and not much has been studied beyond digestibility and growth performance. The purpose of this work was to evaluate the compatibility of protein extracted from BSF flour with corn flour starch within an extruded balanced shrimp feed model through molecular dynamics simulations, for which cohesive energy density and solubility parameter (δ) of both components were determined. The calculations’ results for the protein molecule systems yielded an average δ of 14.961 MPa0.5, while the δ for starch was calculated to be 23.166 MPa0.5. The range of difference between both δ (10 > δ > 7) suggests that the interaction of the BSF protein with corn starch is of a semi-miscible nature. These results suggest that it is possible to obtain a stable starch-protein mixture through the extrusion process.

Solubility, Thermodynamic Parameters, and Dissolution Properties of 17-α Hydroxyprogesterone in 13 Pure Solvents.

The static gravimetric method was used to measure the solubility of 17-α hydroxyprogesterone (OHP) in 13 pure solvents ranging from 278.15 to 323.15 K. The results indicate that the experimental solubility of OHP increases with increasing temperature. The experimental solubility data were correlated by the selected van't Hoff model, λh model, modified Apelblat model, Yaws model, and nonrandom two-liquid (NRTL) model. The fitting results show that the Yaws model can give better correlation results by fitting 13 different pure solvent systems. Based on the NRTL equation, the thermodynamic analysis of solubility data showed that the mixing process was spontaneous. The Hansen solubility parameters (HSPs) and solvent effect were applied to explore these solubility characteristics. Finally, the thermodynamic properties ΔsolH°, ΔsolS°, ΔsolG°, %ξH, and %ξTS were calculated by the van't Hoff model equation. The results showed that ΔsolH°, ΔsolS°, and ΔsolG° are all positive values, indicating that the dissolution of OHP in the selected solvent is an endothermic reaction with increasing entropy.

Liquid- liquid (Cyclohexanone: Cyclohexanol) separation using augmented tight nanofiltration membrane: A sustainable approach

Organic solvent nanofiltration (OSN) is an incipient technology in the field of organic liquid-liquid separation. The incomplete separations and complexity involved in these, forces many organic liquids to be released as effluents and the adverse effects of these on environment is enormous and irreparable. The work prominences on the complete separation of industrially significant cyclohexanone: cyclohexanol (keto-alcohol oil) and heptane: toluene mixtures. The separations of these above-mentioned organic liquid mixtures were carried out using the fabricated Lewis acid modified graphitic carbon nitride (Cu2O@g-C3N4) incorporated polyvinylidene difluoride (PVDF) composite membranes. These fabricated membranes showed a separation factor of 18.16 and flux of 1.62 Lm−2h−1 for cyclohexanone: cyclohexanol mixture and separation of heptane and toluene mixture (with heptane flux of 1.52 Lm−2h−1) showed a separation factor of 9.9. The selectivity and productivity are based on the polarity and size of the organic liquids. The role of Cu2O@g-C3N4 is influencing the pore size distribution, increased divergence from solubility parameters, polarity, solvent uptake and porosity of the composite membranes. The developed composite membranes are thus envisioned to be apt for a wide range of liquid-liquid separations due to its implicit nature.

Ultra‐strong and biodegradable nanocomposite fibers of poly(butylene adipate‐co‐terephthalate)/cellulose nanocrystal prepared by dry‐jet wet spinning

AbstractFiber‐based products constitute a significant portion of plastic waste and cause environmental damage. In particular, discarded sanitary masks and fishing gear disintegrate into microfiber plastics, posing a significant threat to human health and ecosystems. In this study, we developed robust biodegradable nanocomposite fibers of poly(butylene adipate‐co‐terephthalate) (PBAT)/cellulose nanocrystals (CNCs) (1 and 2 wt%) through dry‐jet wet spinning, by using dimethyl sulfoxide (DMSO) as a common solvent. The control PBAT fibers exhibit remarkable mechanical performance with tensile strength and toughness of 160.0 MPa and 43.0 MJ m−3, respectively. CNC addition has a toughening effect with slightly reduced strength but enhanced toughness (148.8 MPa and 69.0 MJ m−3, respectively, for 2 wt% CNC); their mechanical performances are superior to those of previously reported PBAT‐based materials. The remarkable performance of the fibers is attributed to a highly oriented structure with a total draw ratio of 15 after post‐hot drawing. The control and nanocomposite fibers exhibit spot‐like patterns in 2D wide‐angle x‐ray diffraction patterns with Herman's orientation factor of 0.54–0.58. The theoretical Hansen solubility parameter confirmed the poor chemical affinity between the PBAT and CNC. Nonetheless, the rheological characterization revealed that well‐dispersed CNCs with DMSO produced a physical network in the PBAT matrix, resulting in the toughening effect. Such robust nanocomposite fibers consisting of fully biodegradable components are promising alternatives to nondegradable nylon and polyester fibers.Highlights Robust biodegradable nanocomposite fibers of PBAT and CNC are prepared. Nanocomposite fibers are dry‐jet wet spun using DMSO as a common solvent. PBAT fibers exhibit strength and toughness of 160.0 MPa and 43.0 MJ m−3. 2 wt% CNC toughens the PBAT fibers with an enhanced toughness of 69.0 MJ m−3. Rheological results confirm the toughening effect of well‐dispersed CNC in PBAT.

Thermodynamic Description of Liquid Crystalline N(p-n-Alkyloxybenzyliden)-p’-Toluidines with Organic Solvents

Solubility polytherms of nematic (smectic-nematic) N(p-n-alkyloxybenzyliden)-p’-toluidenes (n-alkyl = C4H9, C9H19, C10H21) in organic solvents have been studied. Thermal analysis, visual-polythermal and solubility methods were used. The solution enthalpies of these mesogens in 8 solvents (n-hexane, n-heptane, benzene, p-xylene, cyclohexane, methylcyclohexane, ethanol, n-propanol) were determined. To calculate the solubility polytherms, thermodynamic methods based on the Hildebrand solubility parameters were used. The advantage of the proposed calculation method is that it requires a minimum of experimental parameters (fusion enthalpy and melting temperature of pure mesogen) and the data obtained from the structural formula (group contribution increments) of a mesogen to evaluate its solubility polytherms.

Determination of Solubility and Thermodynamic Parameters of Triamterene in Pure and Ethanol-Modified Subcritical Water at Various Temperatures

Determination of Solubility and Thermodynamic Parameters of Triamterene in Pure and Ethanol-Modified Subcritical Water at Various Temperatures

Divinyl polysiloxane modified polyacrylate for promoting the directional migration of disperse dyes in digital jet dyeing of polyester fabric without washing

Future developments in the printing and dyeing industry will involve greenisation and personalisation. Less/no water digital technology has drawn much attention over traditional printing and dyeing for reducing carbon and emissions. Based on the solubility parameter difference between disperse dyes and monomers, divinyl polysiloxane modified polyacrylate (PSMA) with the directional migration effect for disperse dyes was prepared herein via mini-emulsion polymerisation. PSMA was used as wash-free polymer additive in the digital jet dyeing of polyester fabrics with disperse dyes, which yielded wash-free dyed fabrics with high color yield and color fastness. The results showed that PSMA achieved the optimum overall performance at a molar ratio of octamethylcyclotetrasiloxane to 1,3-divinyltetramethyldisiloxane 44:1 and divinyl polysiloxane dosage of 4 wt%. PSMA had the best tensile properties, good flexibility, certain hydrophobicity and high directional migration of disperse dyes. When the PSMA dosage was 9 wt% in the wash-free ink, the front and back color yield of the wash-free dyed fabric were 18.23 and 13.56, respectively. Compared with the fabric dyed with pure liquid disperse red, the front color yield of the wash-free dyed fabric increased by about 35.2 % and the back color yield had a little change. Its color fastness to dry/wet rubbing were improved from grade 3 to 4 and from grade 2–3 to 3, respectively. The handle of the wash-free dyed fabric basically maintained the level of original fabric.

Molecular dynamics simulation of bonding role of cyclic borate ester in improving mechanical properties of the HTPB propellant

Excellent mechanical properties are the fundamental requirement for the practical application of solid propellants. However, solid oxidant fillers such as hexahydro-1,3,5-trinitros triazine (RDX) seriously weaken the mechanical strength of the propellant due to poor adhesion with the binder matrix. In this work, novel cyclic borate ester (CBE) bonding agents with long-chain alkyl moiety were designed by the molecular dynamics (MD) method to improve the unfavorable interfacial bonding effect. The interface models, which consist of RDX substrate and binder matrix where hydroxyl-terminated polybutadiene (HTPB) crosslinked with curing agents, were constructed to reveal the interface enhancement mechanism by CBE bonding agents. The results indicate that the designed CBE bonding agents with appropriate solubility parameters (SPs) can migrate from the binder matrix to the RDX surface. Besides, CBE bonding agents exhibit strong interaction with RDX compared to the binder matrix due to the formation of hydrogen bonds. Finally, the simulated tensile tests with two tensile modes showed that CBE bonding agents can enhance the interfacial strength and reduce stress softening rates by the calculation of debonding work. Moreover, this improvement can be controlled by adjusting the chain length of CBE bonding agents. The results obtained in this work deepen the understanding of the interfacial strengthening mechanism of bonding agents for solid propellants and provide a framework for designing high-performance bonding agents based on the MD method.

Compatibility analysis between natural rubber/polybutadiene rubber and protective waxes based on experiments and materials studio simulations

AbstractProtective waxes are typically mixtures of paraffin and microcrystalline waxes that retard the aging of unsaturated rubbers and are widely used in rubber products. The wax solubility of rubber products is important for understanding the migration behavior and film formation of waxes and determining the appropriate wax content in rubber compounds. In this article, protective waxes were applied to natural rubber (NR)/polybutadiene rubber (BR) based sidewall rubber and the compatibility between NR and BR and the protective wax dissolution in these rubbers were investigated with a focus on the former investigation through Materials Studio simulations. It was found that the simulation results are strongly correlated with the wax migration test results on compounded and cured rubber at different NR/BR mass ratios. Blends and mesoscopic dynamics simulations yielded good compatibility between NR and BR and favorable blend morphology. By analyzing the solubility parameter, R value, mean square displacement and diffusion coefficient of wax chains with different lengths in the NR/BR matrix, the mechanism and reasons for the wax precipitation variation of protective waxes at varying NR/BR mass ratios were analyzed from a microstructural point of view, which provides strong theoretical support for the design of the molecular structure of protective waxes.

Oleic acid-modified layered double hydroxide for Pickering emulsions: (I) Interfacial properties

Layered double hydroxides (LDHs) are one type of potential emulsifiers for Pickering emulsions. Surface modification can regulate their surface properties, thereby affecting their emulsifying behavior. However, there is still a lack of full understanding of the impact of surface modification on their surface properties. In the current work, one Mg3Al-Cl LDH was modified using oleic acid (OA), obtaining six OA-modified products with different OA loadings. Their contact angles and relative dielectric constants were determined, and their surface properties including the interfacial free energies (γ) and solubility parameters (δ) were then estimated from the data. Their apparent molar volumes were estimated using the γ and δ data. OA molecules are coated on the LDH surface via the bidentate bonding mode to form monolayers. The OA modification has no obvious impact on the structure and morphology of LDH particles, but can significantly affect their surface properties. This work provides a better understanding of the dependence of surface properties of LDHs on the surface modification.

Extraction, recovery, and characterization of lignin from industrial corn stover lignin cake

Lignin utilization in value-added co-products is an important component of enabling cellulosic biorefinery economics. However, aqueous dilute acid pretreatments yield lignins with limited applications due to significant modification during pretreatment, low solubility in many solvents, and high content of impurities (ash, insoluble polysaccharides). This work addresses these challenges and investigates the extraction and recovery of lignins from lignin-rich insoluble residue following dilute acid pretreatment and enzymatic hydrolysis of corn stover using three extraction approaches: ethanol organosolv, NaOH, and an ionic liquid. The recovered lignins exhibited recovery yields ranging from 30% for the ionic liquid, 44% for the most severe acid ethanol organosolv condition tested, and up to 86% for the most severe NaOH extraction condition. Finally, the fractional solubilities of different recovered lignins were assessed in a range of solvents and these solubilities were used to estimate distributions of Hildebrand and Hansen solubility parameters using a novel approach.