Low Molecular Weight Aromatic Compounds Research Articles

Insights on kraft lignin degradation in an anaerobic environment

Lignin is an aromatic macromolecule and one of the main constituents of lignocellulosic materials. Kraft lignin is generated as a residual by-product of the lignocellulosic biomass industrial process, and it might be used as a feedstock to generate low molecular weight aromatic compounds. In this study, we seek to understand and explore the potential of ruminal bacteria in the degradation of kraft lignin. We established two consortia, KLY and KL, which demonstrated significant lignin-degrading capabilities. Both consortia reached maximum growth after two days, with KLY showing a higher growth and decolorization rate. Additionally, SEM analysis revealed morphological changes in the residual lignin from both consortia, indicating significant degradation. This was further supported by FTIR spectra, which showed new bands corresponding to the C-H vibrations of guaiacyl and syringyl units, suggesting structural transformations of the lignin. Taxonomic analysis showed enrichment of the microbial community with members of the Dickeya genus. Seven metabolic pathways related to lignin metabolism were predicted for the established consortia. Both consortia were capable of consuming aromatic compounds such as 4-hydroxybenzoic acid, syringaldehyde, acetovanillone, and syringic acid, highlighting their capacity to convert aromatic compounds into commercially valuable molecules presenting antifungal activity and used as food preservatives as 4-hydroxyphenylacetic, 3-phenylacetic, and phenylacetic acids. Therefore, the microbial consortia shown in the present work are models for understanding the process of lignin degradation and consumption in bacterial anaerobic communities and developing biological processes to add value to industrial processes based on lignocellulosic biomass as feedstock.

Microfiltration, ultrafiltration and nanofiltration as a post-treatment of biological treatment process with references to oil field produced water of Moran oilfield of Assam

The selection of an apt technology for the treatment of Oilfield Produced Water (OFPW) depends mainly on the quality of OFPW and methods of pre-and post-treatment processes. The most challenging part of the OFPW treatment process is the removal of Suspended Solid (SS), Oil & Grease (O&G) and dissolved organics. SS and O&G pose an acute problem to the membrane filtration system by fouling the membrane surface which increases operation & maintenance costs and decreases the life of the membrane. Fouling of the membrane surface is mainly attributed to the presence of low molecular weight aromatic compounds and naphthenic acids in the suspended and dissolved organic compounds. Thus, the removal of these suspended and dissolved organic compounds before membrane filtration proffers a challenge to the researchers. In this research, bioremediation process has been applied to remove the organic compounds and the performance and fouling behaviour of hollow fibre Microfiltration (MF), Ultrafiltration (UF) and Nanofiltration (NF) membranes after the bioremediation process has been analyzed in detail. The level of toxicity was determined by comparing the pollutants with the safe discharge limit for disposal into the environment set by Central Pollution Control Board (CPCB), India. The research presents its novelty by using a hydrocarbon-degrading bacteria, Pseudomonas aeruginosa for the Reduction of Organic Loads (ROL) from OFPW of Moran oil field of Upper Assam as a pre-treatment to membrane filtration. The Total Sum Corrected Area (TSCA) method through chromatographic analyses was used for this. The organic loads removal from OFPW by the TSCA method was found to be 67–100%, 100% and 100% after 7, 14 and 21 days of bioremediation respectively. The major parameters in feed OFPW of Moran oil field were found to be pH (7.5–9.3), Total Dissolved Solid (TDS) (1.79–4.75) ppt, O&G (1.78–2.8) ppt, Salinity (2.94–6.98) ppt, Chloride (Cl−) (1.6–3.86) ppt, Bicarbonate (HCO3−) (2.89–4.03) ppt. It was observed that the ranges of pollutants removal by NF was highest such as TDS (26–86%), salinity (81–86%), turbidity (78–94%), hardness (67–75%), O&G (96–99%), Cl− (80–89%) and HCO3− (95–97%).

Heterogeneous catalytic oxidation for lignin valorization into aromatic compounds over acid-redox bifunctional polyoxometalates

Lignin, as the largest renewable aromatic resource on the planet, has significant potential for the production of value-added platform chemicals. In this work, we synthesized a series of cesium-exchanged acid-redox bifunctional polyoxometalates (POMs) and evaluated their performance as catalysts for the depolymerization of birch lignin into low molecular weight aromatic compounds. The Cs3H2PMOV2O40 catalyst exhibited the highest activity, resulting in a monomer yield of approximately 13.6 %. Gel permeation chromatography (GPC), heteronuclear single quantum coherence (HSQC) spectroscopy, and gas chromatography-mass spectrometry (GC-MS) analysis confirmed the effective cleavage of β-O-4, β-5, and β-β linkages in the lignin polymer. The proposed reaction mechanism for the lignin depolymerization over cesium-exchanged POMs was also discussed. Our results demonstrate the potential of cesium-exchanged POMs as effective catalysts for the conversion of lignin into value-added chemicals, thereby contributing to the complete sustainable utilization of lignocellulose.

The key odor-active components differed in cultured agarwood from two germplasms of Aquilaria. sinensis trees

To tentatively identify the key odor-active components and compare the odor profiles of cultured agarwood from ordinary and Qi-Nan Aquilaria. sinensis trees, headspace solid-phase microextraction gas chromatography-olfactometry-mass spectrometry (HS-SPME-GC–O–MS) coupled with aroma extraction dilution analysis (AEDA) were used to analyze ordinary(OA)and Qi-Nan agarwood(QNA) compared to non-resinous whitewood. From the 61 odorants found in agarwood, 20 key odor-active components were screened with flavor dilution (FD)≥ 3. Among them, FDs of cis-Eudesm-6-en-11-ol，(E)-isovalencenal and guaiol in OA were higher than those in QNA, which explained for the odor profile of stronger floral and sweet attributes in OA group at ambient temperature. When temperature became higher, low molecular weight aromatic compounds increased greatly and further differed OA and QNA. For the 2-(2-Phenylethyl) chromone derivatives(PECs)in QNA and OA were distinct and consequently pyrolyzed into different aromatic compounds. The results strongly suggested QNA and OA maintained different odor-active components, which lead to their own unique odor profiles.

Aerobic post-treatment of effluent from anaerobic reactors fed with residues from 1G and 2G sugarcane biorefineries.

This study aimed to evaluate an activated sludge system as a post-treatment step of anaerobic effluents from the co-digestion of sugarcane vinasse and hemicelluloses hydrolysate. The system consisted, initially, of a two-stage anaerobic system followed by a continuously fed activated sludge, all in bench scale. After adaptation of aerobic microorganisms to effluent conditions, the anaerobic digestion was conducted in a single-stage anaerobic reactor, increasing the influent organic loading rate (OLR) of activated sludge from 0.73 to an average of 2.36 gCOD/L·day. Under optimal conditions (12-h hydraulic retention time [HRT]), a 62 ± 9% efficiency was observed on the aerobic post-treatment, resulting in effluent chemical oxygen demand (COD) of 414.3 ± 95 mg/L. Overall efficiency of the combined system (anaerobic + aerobic) averaged 88 ± 3%. Influent and effluent characteristics were then analyzed by Folin-Ciocalteau method, UV-Vis spectrophotometry, and gas chromatography-mass spectrometry (GC-MS) for identification of potentially toxic and recalcitrant compounds. Compounds that absorb light within the visible spectra were well removed by the combined treatment system. Most compounds identified by GC-MS in the influent were completely removed by aerobic microorganisms. Saturated fatty acids such as adipic acid, hexadecanoic acid, and octadecanoic acid were observed in the final effluent, as well as other potentially toxic compounds such as stigmasterol, di-isobutyl phthalate, and benzene. Activated sludge proved to be an efficient post-treatment for anaerobic co-digestion, able to cope with changes of anaerobic effluent quality and providing a final effluent of stable organic load. However, phenol removal was not efficient and further studies could be performed to optimize its degradation. PRACTITIONER POINTS: Conventional activated sludge with a 12-h HRT was capable of handling significant OLR variation, providing a final effluent with lower and stable COD concentration. Glucose addition for carbon supplementation was necessary during the start-up of activated sludge. Compounds that absorb light within the visible spectra were mostly removed by the combined (anaerobic-aerobic) treatment system. Most potentially toxic compounds were well removed in the post-treatment system. Saturated fatty acids, VFA, phenols, and low molecular weight aromatic compounds remained in the final effluent.

Individual and Combined Inhalational Sedative Effects in Mice of Low Molecular Weight Aromatic Compounds Found in Agarwood Aroma.

Agarwood is known to have a sedative effect and the less studied volatile aromatic constituents it contains may have contribution to the activity. In this study, two Kyara grade (highest-grade agarwood in Japan) samples were extracted using headspace-solid phase microextraction (HS-SPME) and analyzed through gas chromatography-mass spectrometry (GC-MS). Six low molecular weight aromatic compounds (LACs) and one structurally simple compound (diethylene glycol monoethyl ether) present in the aromas were individually evaluated for inhalational sedative activity in mice through open field test. Doses of 0.0001 g/L to 1 g/L were prepared for each compound and administered to mice (n = 6/dose/compound). Results revealed all compounds decreased spontaneous motor activity at almost all doses. Strongest sedative activity of each compound reduced total spontaneous motor activity by more than half against control, demonstrating their contribution to agarwood aroma and potential as independent sedating agents. Mixtures of compounds using their most effective dose were made and evaluated again for inhalational sedative effect. Interestingly, the combination of all compounds showed no significant effect and even caused stimulation in mice movements. This result suggests antagonistic-like interaction between the compounds, which is probably due to structural similarities. Consequently, it implies the other constituents present in agarwood, along with LACs, are also important to the overall sedative activity.

Chemical Constituents and Anti-Inflammatory Effect of Incense Smoke from Agarwood Determined by GC-MS

Agarwood is generally used to make incense sticks in China and Southeast Asia. It emits smoke with a pleasant odor when burned. There are few reports on the chemical components of smoke generated by burning or heating agarwood. The agarwoods were produced by the whole-tree agarwood-inducing technique (AWIT), agarwood induced by axe wounds (AAW), burning-chisel-drilling agarwood (BCDA), wood of Aquilaria sinensis trees (AS), respectively. Herein, we used GC-MS to analyze the chemical constituents of incense smoke generated from AWIT, AAW, BCDA, AS, and the extracts of sticks from agarwood produced by the whole-tree agarwood-inducing technique (EAWIT), and 484 compounds were identified. A total of 61 chemical constituents were shared among AWIT, AAW, and BCDA. The experimental data showed that aromatic compounds were the main chemical constituents in agarwood smoke and that some chromone derivatives could be cracked into low-molecular-weight aromatic compounds (LACs) at high temperature. Furthermore, agarwood incense smoke showed anti-inflammatory activities by inhibiting lipopolysaccharide- (LPS-) induced TNF-α and IL-1α release in RAW264.7 cells.

Amorphous low molecular weight aromatic compounds possessing no weight loss behavior in fluoroalkyl end-capped vinyltrimethoxysilane oligomeric silica/hexagonal boron nitride nanocomposites even after calcination at 800°C

Fluoroalkyl end-capped vinyltrimethoxysilane oligomer [RF-(CH2CHSi(OMe)3)n-RF; n = 2, 3; RF = CF(CF3)OC3F7] undergoes the sol–gel reactions in the presence of hexagonal boron nitride (h-BN) nanoparticles and low molecular weight aromatic compounds (ArHs) such as bisphenol AF (BPAF) and 1-(2-naphthyl)ethanol (Naph-EtOH) under alkaline conditions at room temperature to afford the corresponding fluorinated oligomeric silica/h-BN/ArHs nanocomposites [RF-(VM-SiO3/2)n-RF/h-BN/ArHs]. TG–DTA analyses and XRD spectra measurements show that the encapsulated ArHs in the fluorinated oligomeric silica/h-BN nanocomposites exhibit an amorphous structure, affording no weight loss corresponding to the contents of the ArHs in the nanocomposites even after calcination at 800°C, although the simple blend hybrids of the RF-(VM-SiO3/2)n-RF/h-BN nanocomposites and the original ArHs provide not only the crystal characteristic toward the ArHs but also a clear weight loss behavior in proportion to the contents of the ArHs in the blend hybrids after calcination at 800°C. 1H MAS NMR spectra, UV–Vis spectra, and fluorescent spectra of the RF-(VM-SiO2)n-RF/h-BN/ArHs nanocomposites obtained through the sol–gel reactions under alkaline conditions showed the presence of the ArHs in the nanocomposites, respectively.

A simple fractionation method and GPC analysis of organosolv extracts obtained from lignocellulosic materials

The elucidation of lignin structural features is necessary for the efficient application of this polymer. Fractionation is an effective technique to achieve homogeneous lignin fractions, helping to better understand its composition and structure, and improving its use as source of phenolic compounds. This work develops a new and simple fractionation method of organosolv extracts obtained from lignocellulosic materials that enables the selective separation of lignin (from complex macromolecules to low molecular weight aromatic compounds originated from their degradation) from saccharides derived from hemicelluloses and cellulose. For this purpose, the non-catalytic organosolv extraction of lignin from almond shells was performed with dioxane/water mixtures and then the successful fractionation of the organosolv extracts with anhydrous tetrahydrofuran was achieved, resulting in the selective separation of lignin (lignin fraction) from saccharides (saccharide fraction). Gel permeation chromatography (GPC), thioacidolysis, and GC-MS were used as analytical methods to qualitatively determine the purity of both fractions. In addition, GPC was also used to quantify the content of lignin monomers and furfural in the organosolv extracts, thus allowing valuable information on the state of degradation of the lignin and hemicelluloses extracted to be obtained, respectively. The application of the GPC method also enabled the determination of the molecular weight distribution of the extracted lignin in the same analysis.

Depolymerization of Alkaline Lignin in the Medium of Supercritical 2-Propanol

The results of optimizing the conditions of alkaline lignin depolymerization in a medium of supercritical 2-propanol in order to obtain low molecular weight aromatic compounds, which are potential renewable raw materials for organic synthesis, production of various products and materials, are presented. The designed experiment was applied, based on a central composite rotatable uniform plan design of the second-order for three variables (temperature, process time, liquid module) varied at five levels. The target parameters for optimization were the degree of conversion of lignin to soluble products and their molecular weight. Based on the obtained dependences the optimal depolymerization conditions (450°C, 8 min, liquid module 20) were determined, which ensured the degree of lignin conversion at the level of 73%. Using high-resolution mass spectrometry, it was shown that the resulting depolymerization products have an extremely complex component composition, which includes mainly monomeric and dimeric phenols.

Hydrotreatment of pyrolytic lignins to aromatics and phenolics using heterogeneous catalysts

The pyrolysis of lignocellulosic biomass generates a liquid product, known as pyrolysis oil, that can be further processed into biofuels and value-added chemicals. During pyrolysis, cellulose and hemicelulose fractions are converted into a range of water-soluble sugar derivatives, for which several valorisation strategies exist. On the other hand, lignin is broken down into so-called pyrolytic lignin, a water-insoluble complex mixture of aromatic oligomers that requires different upgrading strategies than the sugar rich fraction. Here, we report an experimental study on the valorisation of pyrolytic lignin via catalytic hydrotreatment in the absence of an external solvent. A variety of carbon-supported noble-metal heterogeneous catalysts were tested (Ru/C, Pd/C, Pt/C and Rh/C), as well as conventional hydrotreatment catalysts (sulphided NiMo/Al2O3 and CoMo/Al2O3) to obtain valuable low molecular weight aromatic and phenolic compounds. Overall, depolymerized liquids were obtained with organic yields of up to 63 wt%. Pd/C was shown to be the best catalyst, yielding 59 wt% of monomers based on the organic product (i.e. 33 wt% based on pyrolytic lignin intake). While noble metal catalysts favored higher monomer yields, though with some over-reduction of aromatic rings to saturated hydrocarbons, sulphided catalysts were more efficient in deoxygenation and aromatization reactions, but yielded less monomers. The hydrocracking efficiency was shown to be strongly dependent on the reaction temperature. Based on the experimental data, a global reaction network is proposed. The high monomer yields reveal the potential of catalytic hydrotreatment for the upgrading of pyrolytic lignin into valuable phenolics and aromatics.

An automated microliter-scale high-throughput screening system (MSHTS) for real-time monitoring of protein aggregation using quantum-dot nanoprobes

Protein aggregation is the principal component of numerous protein misfolding pathologies termed proteinopathies, such as Alzheimer’s disease, Parkinson’s disease, prion disease, and AA amyloidosis with unmet treatment needs. Protein aggregation inhibitors have great potential for the prevention and treatment of proteinopathies. Here we report the development of an automated real-time microliter-scale high throughput screening (MSHTS) system for amyloid aggregation inhibitors using quantum-dot nanoprobes. Screening 504 crude extracts and 134 low molecular weight aromatic compounds revealed the relationship of amyloid-β (Aβ) aggregation inhibitory activities of plant extracts using a plant-based classification. Within the eudicots, rosids, Geraniales and Myrtales showed higher activity. Screening low molecular weight aromatic compounds demonstrated that the structure of tropolone endows it with potential Aβ aggregation inhibitory activity. The activity of the most active tropolone derivative was higher than that of rosmarinic acid. MSHTS also identified three chaperone molecules as tau aggregation inhibitors. These results demonstrate that our automated MSHTS system is a novel and robust tool that can be adapted to a wide range of compounds and aggregation-prone polypeptides.

Alkali lignin depolymerization under eco-friendly and cost-effective NaOH/urea aqueous solution for fast curing bio-based phenolic resin

It is still a challenge to use lignin without any pretreatment due to its high molecular weight, strong steric hindrance, and low reactivity. To prepare value-added low molecular weight aromatic compounds for preparation of lignin-based phenolic resins, alkali lignin (AL) was depolymerized under low cost and environmental-friendly NaOH/urea aqueous solution at low temperature in this paper. The molecular structure changes of the depolymerized AL (DAL) products were characterized by MALDI-TOF-MS, 1H NMR, and FT-IR spectrophotometers. Low molecular weight aromatic compounds mainly composed of phenyl-propane trimers were prepared after depolymerization. The active proton content at C5 position increased from 0.03 mmol/g to 0.26 mmol/g, and the phenolic hydroxyl group content increased from 0.07 mmol/g to 0.12 mmol/g. Moreover, a depolymerization mechanism was proposed to explicate the depolymerization process. AL and DAL products were used for the preparation of lignin-based phenolic resins. The chemical properties of lignin-based phenolic resins were studied by liquid-state 13C NMR and FT-IR spectroscopy, and its physical properties were also investigated. The results indicated that the depolymerized alkali lignin-phenol-formaldehyde (DALPF) resins exhibited enhanced properties, such as faster curing rate, lower formaldehyde emission, and higher bonding strength, compared to alkali lignin-phenol-formaldehyde (ALPF) resins.

Agarotetrol: a source compound for low molecular weight aromatic compounds from agarwood heating.

Agarwood is known to generate a distinct fragrance upon heating and is used as both a medicine and a fragrant wood. Low molecular weight aromatic compounds (LACs) such as benzylacetone are emitted from agarwood on heating and have a sedative effect on mice. These are detected exclusively in the headspace vapor of heated agarwood and are absent in the wood itself; hence, some compounds in agarwood are thought to be converted to LACs by the process of heating. In this study, different fractions obtained from agarwood were analyzed to reveal the source compounds of LACs. Some LACs detected in the resinous agarwood were absent from the non-resinous parts and confirmed as characteristic of the resinous parts. The essential oil and hydrosol of agarwood obtained by distillation were analyzed by gas chromatography-mass spectrometry (GC-MS). Sesquiterpenes were detected in the essential oil, and sesquiterpenes and a variety of LACs were detected in the hydrosol. A hot water extract of agarwood remaining in the distillation flask after distillation was analyzed by high-performance liquid chromatography (HPLC), and agarotetrol was found to be the main compound. Purified agarotetrol was heated in a glass vial and its headspace vapor was analyzed by solid-phase microextraction GC-MS. Benzylacetone and other LACs were detected. These results indicate that agarotetrol, a chromone derivative, contributes to the fragrance of agarwood through the generation of LACs upon heating.

Preparation of Fluoroalkyl End-Capped Oligomer/Cyclodextrin Polymer Composites: Development of Fluorinated Composite Material Having a Higher Adsorption Ability toward Organic Molecules

Fluoroalkyl end-capped vinyltrimethoxysilane oligomer [RF-(CH2CHSi(OMe)3)n-RF; RF = CF(CF3)OCF7, n = 2, 3; RF-(VM)n-RF] was applied to the preparation of fluoroalkyl end-capped vinyltrimethoxysilane oligomer/α-, β-, γ-cyclodextrin polymers (α-, β-, γ-CDPs) composites [RF-(VM-SiO2)n-RF/α-, β-, γ-CDPs] by the sol-gel reaction of the corresponding oligomer in the presence of the α-, β-, γ-CDPs under alkaline conditions. The RF-(VM-SiO2)n-RF/α-, β-, γ-CDPs composites thus obtained were found to give a good dispersibility toward the traditional organic media except for water, and were applied to the surface modification of glass to provide a sueperoleophilic/superhydrophobic characteristic on the modified surface, although the corresponding RF-(VM-SiO2)n-RF nanocomposites can give a usual oleophobic/superhydrophobic property on the surface. These composites powders were also found to be applicable to the packing material for the column chromatography to separate the mixture of oil/water and the water in oil (W/O) emulsions. More interestingly, these composite powders were found to have a higher adsorption ability toward not only low-molecular weight aromatic compounds such as bisphenol A and bisphenol AF but also volatile organic compounds, compared to that of the pristine α-, β-, γ-CDPs.

Continuous Electrochemical Reactor for Conversion of Biorefinery Lignin to Aromatic Compounds

Lignin is one of the most abundant biopolymers on Earth, constituting about 20 to 30 percent of wood; it is one of the major waste materials of the pulp and paper industry and emerging biorefineries [1]. Utilization of lignin as a raw material for industrial chemicals would provide additional revenue streams for pulping mills and biorefineries, and especially in the case of the latter, reduce the overall cost of generating biofuel. Lignin depolymerization is the main approach to conversion of the biopolymer to value-added chemicals. It occurs by cleavage of C-C and C-O linkages between lignin units to produce low molecular weight aromatic compounds. However, the high molecular weight and three dimensional structure of lignin results in a high amount of energy to break down these linkages [4]. Electrochemical techniques applied to this problem could address issues like low selectivity toward desirable products, high energy consumption and low reaction rates. This presentation will focus on our efforts to develop continuous electrochemical processes to convert biorefinery lignin to aromatic compounds useful to industry. We will discuss electrocatalyst development, product stream analysis techniques, and validation of a continuous process that leads to higher yield and selectivity toward useful aromatic compounds.

Evaluation of Pulmonary Function in Car Spray Paint Sprayers

Evaluation of Pulmonary Function in Car Spray Paint Sprayers

Biodegradation of kraft lignin by a newly isolated anaerobic bacterial strain, Acetoanaerobium sp. WJDL-Y2.

An anaerobic kraft lignin (KL)-degrading bacterial strain was isolated from sludge of a pulp and paper mill. It was characterized as Acetoanaerobium sp. WJDL-Y2 by 16S rRNA gene sequencing. The maximum KL degradation capability of strain Y2 was determined to be 24·9% on a COD basis under an optimal condition with temperature of 31·5°C, initial pH of 6·8 and KL to nitrogen (as NH4 Cl) ratio of 6·5 by mass. Growth kinetic studies showed that the KL tolerance of strain Y2 was relatively high (Ki =8120·45mgl(-1) ). Analysing KL degradation products by GC-MS revealed the formation of low-molecular-weight aromatic compounds (LMWACs), including benzene-propanoic acid, syringic acid and ferulic acid. This indicates that strain Y2 can oxidize lignin structure's p-hydroxyphenyl (H) units, guaiacyl (G) units and syringyl (S). In addition, the inoculated sample also contained low-molecular acid compounds, such as hexanoic acid, adipic acid and 2-hydroxybutyric acid, further validating strain Y2's ability to degrade KL. Kraft lignin containing effluents discharged from pulp and paper industries causes serious environmental pollution in developing countries. Due to the immense environmental adaptability and biochemical versatility, bacterial ligninolytic potential deserve to be studied for application in effluent treatment of pulp and paper industry. In this study, an anaerobic lignin-degrading bacterium, Acetoanaerobium sp. WJDL-Y2 (accession no. KF176997),was isolated from the sludge of a pulp and paper mill. Strain Y2 can play an important role in treating pulp and paper wastewater, as well as breaking down materials for biofuel and chemical production.

Preparation and Surface Property of Fluoroalkyl End-Capped Vinyltrimethoxysilane Oligomer/Talc Composite-Encapsulated Organic Compounds: Application for the Separation of Oil and Water

Fluoroalkyl end-capped vinyltrimethoxysilane oligomer [R(F)-(CH2-CHSi(OMe)3)n-R(F); n = 2, 3; R(F) = CF(CF3)OC3F7 (R(F)-VM oligomer)] can undergo the sol-gel reaction in the presence of talc particles under alkaline conditions at room temperature to provide the corresponding fluorinated oligomeric silica/talc nanocomposites (RF-VM-SiO2/Talc). A variety of guest molecules such as 2-hydroxy-4-methoxybenzophenone (HMB), bisphenol A (BPA), bisphenol AF, 3-(hydroxysilyl)-1-propanesulfonic acid (THSP), and perfluoro-2-methyl-3-oxahexanoic acid (R(F)-COOH) are effectively encapsulated into the R(F)-VM-SiO2/Talc composite cores to afford the corresponding fluorinated nanocomposites-encapsulated these guest molecules. The R(F)-VM-SiO2/Talc composites encapsulated low molecular weight aromatic compounds such as HMB and BPA can exhibit a superoleophilic-superhydrophobic characteristic on the surfaces; however, the R(F)-VM-SiO2/Talc composite-encapsulated THSP and R(F)-COOH exhibit a superoleophobic-superhydrophilic characteristic on the modified surfaces. In these nanocomposites, the R(F)-VM-SiO2/Talc/THSP composites are applicable to the surface modification of polyester fabric, and the modified polyester fabric possessing a superoleophobic-superhydrophilic characteristic on the surface can be used for the membrane for oil (dodecane)/water separation. In addition, the R(F)-VM-SiO2/Talc composites-encapsulated micrometer-size controlled cross-linked polystyrene particles can be also prepared under similar conditions, and the obtained composite white-colored particle powders are applied to the packing material for the column chromatography to separate water-in-oil (W/O) emulsion.

Characterization of asphaltic oil occurrences from the southeastern margin of the Basque-Cantabrian Basin, Spain

A geochemical investigation has been undertaken on biodegraded hydrocarbons in outcropping reservoirs of the south-eastern margin of the Basque-Cantabrian Basin (Alava sector). The aims of the study were the characterization of the geochemical features and biodegradation level of these hydrocarbons, and the evaluation of their resemblance to oils from the Ayoluengo onshore oil field by means of isotopic analyses and gas chromatography-mass spectrometry techniques. Most of the samples lack n-alkanes, isoprenoids, low molecular weight aromatic compounds, steranes, homohopanes, diasteranes and triaromatic steroids, whereas hexacyclic and heptacyclic alkanes appear as key compounds although some structures were not totally elucidated. Thermal maturity has been assessed with several parameters and a calculated-equivalent vitrinite reflectance value of around 0.8% was estimated. In addition, gammacerane content, diasterane-to-sterane ratio and C35 to C34 hopanes ratio suggest that the Alava oil shows were derived from a carbonate rock deposited in a reducing, water-stratified and possibly hypersaline environment. Isotopic signatures and other data confirmed that these hydrocarbons are not genetically related to the oils from Ayoluengo and, consequently, their origin is associated with a yet unknown source rock in the basin.