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Structural optimization of activated carbon (AC) mainly relies on experience, which depends on the intrinsic structure of biochar, processing conditions, and the interplay of both parties. A fundam...

In this work, naturally dispersed ash components in bio-carbon composites were prepared from waste spent mushroom substrate. Two kinds of deashing treatments were used to study the role of soluble and poorly soluble ash in the adsorption of NH4+ and increase specific surface area. The role of ash components on pore structure and the adsorption of ammonia nitrogen were systematically investigated. It is revealed that the relationship of ammonium adsorption capacity of three ACs is MAC > MAC-W > MAC-A at the varied pH conditions. Specifically, the ammonia nitrogen adsorption capacity of MAC increases 108.9% as compared with MAC-A. The bigger pore structure and BET of carbon was obtained after absorption due to naturally dispersed ash components exchanged with NH4+. What is more, Na+, K+, and Ca2+ in the ash have a greater effect on the adsorption of ammonia nitrogen of ACs. The struvite formation will consume the Mg2+ and NH4+ ion, leading to the enhanced adsorption properties via chemical deposition. This work provides a new perspective on dispersed ash components in bio-carbon from the low-valued biomass for the ammonia nitrogen removal and specific surface area augment.

This paper investigated experimentally the machining of Ti-6A-4V with a new graphene based cutting fluid. Three different types of graphene oxide (GO) nanofluids with various GO concentrations were applied in a series of cutting experiments. Tool wear, cutting force and the vibration in turning titanium alloy with the new nanofluids as well as conventional coolant were analysed. The working mechanism and different cutting effects caused by the variation of GO concentration and coolant pressure were discussed. The results show that the cutting force was reduced by 50.83 % when GO nanofluids were used. The vibration in the turning Ti-6Al-4 V with GO nanofluids was significantly lower than that in using base fluids. While the Build-up-Edge (BUE) and adhered layers on the rake face were less than those formed in using conventional coolant, the reduction of flank wear was up to 44.1 %, 53.9 % and 71.3 % respectively when GO nanofluids with the concentration of 0.1 wt.% GO, 0.3 wt.% GO and 0.5 wt.% GO were applied.

Cobalt–salen-based porous ionic polymers, which are composed of cobalt and halogen anions decorated on the framework, effectively catalyze the CO2 cycloaddition reaction of epoxides to cyclic carbo...

In order to solve the toxic and hazardous issues of the agents in the chemical reduction process of graphene oxide (GO), disodium guanosine 5′-monophosphate (GMP-2Na) was used as an ideal reducing agent for the synthesis of functionalized GO (FGO) for lipase immobilization. At the condition of low amount adsorption of GMP-2Na indicated by the N1s spectra of X-ray photoelectron spectroscopy (XPS), the C/O atomic ratio of the FGO increased from 2.09 to 3.12, indicating the reduction of GO. As the amount of GMP-2Na increased, the intensity of the characteristic peak of GO in the XRD pattern decreased, and the I D /I G peak intensity of Raman spectra increased during the functionalization process. It was found that when the concentration of GMP-2Na is 0.20 mg/mL, the degree of hydrophobicity of FGO is conducive to the formation of optimal conformation of lipase. After immobilization, the activity of the immobilized enzyme reaches twice the value of free enzyme. At the same time, the protein loading reaches to 600 mg/g. The immobilized enzyme showed enhanced durability since no obvious decrease was observed after incubation for 8 h at pH 6.0 and pH 7.0. After storage for 35 days, the activity of GO-G@ enzyme was 54.47% higher than that of free enzyme. GO reduced by GMP-2Na provides a possibility to obtain a highly efficient lipase immobilization carrier.

In past decades, more research efforts have been devoted to the processing of thermally conductive polymer composite and less on fundamental aspects of heat conduction in polymeric materials. Here we presented a polymeric hybrid system comprising of polymer chain and short thermal linkers that show promising thermal conductivity and optical transparency. This was achieved by engineering their intermolecular interactions without incorporating traditional fillers (carbon, ceramic and metal). Polyvinyl alcohol (PVA) with different degrees of hydrolysis has been engineered to achieve enhanced thermal conduction by using small organic linkers (OL) having symmetric terminal groups such as ethylene diamine (ED) and ethylene glycol (EG) and hybrid terminal groups like ethanolamine (EA). Comparing with ED and EG, EA has been demonstrated more effective in enhancing thermal conductivity for both PVAs with different degrees of hydrolysis (88% and 99+%). Presence of bulkier acetate group in PVA (88% hydrolysis) restricted the efficient thermal connections by steric hindrance. Optimized pairing of terminal groups of OLs was thus found to provide an interesting handle to manipulate the thermal conductivity. Additionally, degree of hydrolysis of polymer matrix is another crucial factor to effectively engineer thermal conductivity. In summary, impact of functional group, molecular structure, side groups of backbone polymer and organic linkers were found to have substantial impact on overall thermal conductivity of PVA/OL and can be manipulated for efficient thermal management.

Lignin, one of the most abundant natural polymers, has been successfully used as an effective lubricant additive with high value. The chemical structure of lignin is very diverse and strongly affected by both the source of lignin (i.e. plant species) and the lignin extraction process. In this work, a series of lignin from different biomass sources (hard or soft wood) and extraction process (organosolv with or without acid catalyst) has been successfully incorporated into poly(ethylene glycol) (PEG) and fortified lubricating properties were achieved. The effects of different lignin on the rheological, thermal and tribological properties of the lignin/EG lubricants were systematically investigated by different characterization techniques. Lignin in PEG significantly improves the lubricating property, where a wear reduction of 93.8% was observed. The thermal and lubrication properties of the PEG lubricants filled with different kinds of lignin are tightly related to the synergistic state of hydrogen bonding and molecular weight distribution. Lignin with broader molecular weight distribution and higher hydroxyl content shows better adhesion on metal surfaces and strengthened lubricating film, which could be used as the efficient lubricating additives. This work provides a criterion for selecting appropriate lignin as the efficient lubricant additive and accelerates the application of lignin.

Polymer composites are of great interest in thermal conduction applications, while poor filler dispersion and enormous phonon scattering at composite interface become the critical bottleneck for ef...

TiO2 solid acid catalysts with different niobium (Nb) doping ratios (8, 16, and 24 mol%) were synthesized for microwave-assisted catalytic conversion of fructose to hydroxymethylfurfural (HMF). Nb doping has been demonstrated effective to enhance the quantity of acid sites and increase the acid strength. At optimal Nb loading of 16 mol%, it was found that the reaction rate constant and energy efficiency were significantly enhanced by 32 and 49%, respectively. The enhancement mechanism of Nb-doping was investigated by both experiment and density functional theory (DFT) calculation. It was revealed that Nb doping promoted the electron transfer from the bulk catalyst to surface sulfonic groups, resulting in enhanced acidity and polarity of sulfonic groups. The electron transfer could strengthen the sulfonic group-water interaction at catalyst surface and created a unique polarized interface region where heat generation and the catalytic reaction can be coupled for enhanced energy efficiency of such reactions.

Lignin strengthened ionic liquids (ILs) have shown high potential to be used as high performance green lubricants. Strengthened lignin-ILs molecular interaction is an effective approach to improve ...

This study investigated the effect of dietary myo-inositol (MI) on alleviating the adverse effect of the high carbohydrate diet in Nile tilapia (Oreochromis niloticus). Six diets contained either low carbohydrate (LC 30%) or high carbohydrate (HC 45%) with three levels of MI supplementation (0, 400 and 1200 mg/kg diet) to each level of the carbohydrate diet. After an 8-week trial, the fish fed 400 mg/kg MI under HC levels had the highest weight gain and fatness, but the fish fed 1200 mg/kg MI had the lowest hepatosomatic index, visceral index and crude lipid in the HC group. The diet of 1200 mg/kg MI significantly decreased triglyceride content in the serum and liver compared with those fed the MI supplemented diets regardless of carbohydrate levels. Dietary MI decreased triglyceride accumulation in the liver irrespective of carbohydrate levels. The content of malondialdehyde decreased with increasing dietary MI at both carbohydrate levels. Fish fed 1200 mg/kg MI had the highest glutathione peroxidase, superoxide dismutase, aspartate aminotransferase and glutamic-pyruvic transaminase activities. The HC diet increased the mRNA expression of key genes involved in lipid synthesis (DGAT, SREBP, FAS) in the fish fed the diet without MI supplementation. Dietary MI significantly under expressed fatty acid synthetase in fish fed the HC diets. Moreover, the mRNA expression of genes related to lipid catabolism (CPT, ATGL, PPAR-&alpha, ) was significantly up-regulated with the increase of dietary MI levels despite dietary carbohydrate levels. The gene expressions of gluconeogenesis, glycolysis and MI biosynthesis were significantly down-regulated, while the expression of the pentose phosphate pathway was up-regulated with the increase of MI levels. This study indicates that HC diets can interrupt normal lipid metabolism and tend to form a fatty liver in fish. Dietary MI supplement can alleviate lipid accumulation in the liver by diverging some glucose metabolism into the pentose phosphate pathway and enhance the antioxidant capacity in O. niloticus.

The capability of sensor systems to efficiently scavenge their operational power from stray, weak environmental energies through sustainable pathways could enable viable schemes for self-powered health diagnostics and therapeutics. Triboelectric nanogenerators (TENG) can effectively transform the otherwise wasted environmental, mechanical energy into electrical power. Recent advances in TENGs have resulted in a significant boost in output performance. However, obstacles hindering the development of efficient triboelectric devices based on biocompatible materials continue to prevail. Being one of the most widely used polymers for biomedical applications, polyvinyl alcohol (PVA) presents exciting opportunities for biocompatible, wearable TENGs. Here, the holistic engineering and systematic characterization of the impact of molecular and ionic fillers on PVA blends' triboelectric performance is presented for the first time. Triboelectric devices built with optimized PVA-gelatin composite films exhibit stable and robust triboelectricity outputs. Such wearable devices can detect the imperceptible skin deformation induced by the human pulse and capture the cardiovascular information encoded in the pulse signals with high fidelity. The gained fundamental understanding and demonstrated capabilities enable the rational design and holistic engineering of novel materials for more capable biocompatible triboelectric devices that can continuously monitor vital physiological signals for self-powered health diagnostics and therapeutics.

Graphene oxide (GO) membrane assembling through edge-edge or plane-plane connection has huge influence on membrane microstructure and thus separation performance. In this work, plane-plane connection of GO sheets was promoted in supported GO membranes by grafting oxalic acid (OA) molecules in GO basal plane. With subsequent crosslinking by ethylene diamine (EDA), better packing structure can be achieved with reduced wrinkling in GO membrane. With this unique approach, restricted swelling, tightly packed laminar structure, reduced wrinkling and improved separation property can be simultaneously achieved. Specifically, membranes were prepared on polydopamine coated porous polyethersulfone (PES) support via pressurization filtration method. GO membrane thickness was controlled within the range of 100–400 nm with d-spacing of × 10−8 mol m−2 s−1 Pa−1. This membrane also excels in liquid separation, where methylene blue rejection rate of 99.9% and ion (Na+, K+, Mg2+, Cl-, and SO42-) rejection rate of > 98.1% were achieved.

In this paper, bubble-on-plate structure is realized on hollow IF-MoS2/reduced graphene oxide (HIF-MoS2/RGO) nanocomposites. HIF-MoS2 nanocages templated with the generated ammonia (NH3) are connected to RGO through the interlayered MoS2. The as-prepared HIF-MoS2/RGO is added into an ionic grease to study the tribological behavior of HIF-MoS2/RGO. For comparison, commercial grade MoS2 nanoparticles, single RGO or HIF-MoS2 or their physical mixture are also studied. Tribological results show that, compared with other additives, HIF-MoS2/RGO nanocomposites have the best anti-wear properties especially under higher load of 3.0 GPa. The wear reduction of HIF-MoS2/RGO reinforced grease under 2.5 GPa and 3.0 GPa reached 67% and 96%, respectively. In addition, HIF-MoS2/RGO reinforced grease achieves much lower and stable friction coefficient (0.079, the value of neat grease is 0.098) under 3.0 GPa. HIF-MoS2/RGO reinforced grease maintains very low friction coefficient and wear up to 4.1 GPa, while the normal MoS2 and RGO show high wear at the pressure up to 3.0 GPa. It is proposed that HIF-MoS2 nanocages on RGO act as rolling balls during friction resulting in better separation of steels.

Covalent bonding is widely adopted in graphene oxide (GO) membrane to improve structural integrity and restrict swelling, while it comes with a price of enlarged d-spacing and sacrifices membrane selectivity. This work offers a facile strategy to break the trade-off between membrane stability and selectivity. Specifically, graphene oxide (GO)/reduced graphene oxide (rGO) hybrid membranes were fabricated by a controlled pre-cross-linking method. With this method, restricted swelling by cross-linking and reduced d-spacing by GO reduction can be achieved simultaneously by controlling reaction time. Membranes were prepared on porous alumina support by vacuum filtration method. Two different d-spacing values (∼12.0 and ∼7.5 A) were found in the hybrid membrane, representing the layer structures of expanded GO interspacing with inserted cross-linker and reduced layer spacing after GO reduction. The presence of such mixed layer structures enables restricted swelling, excellent mechanical strength, and unique sep...

Fast reaction rate under mild reaction conditions is highly desired in the oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA). Continuous control of pH and temperature is the key to accelerate the reaction rate. This work offers a binary addition method enabling continuous control of solution pH during the entire reaction period and thus expedites reaction rate in each step along the reaction path. The fluctuation of reaction temperature from binary addition is then addressed by a coupled microwave heating method. FDCA yield of >99 mol % can be achieved within 30 min under mild reaction conditions of atmospheric pressure and low temperature of

Superhydrophobic polysulfone (PSU)/carbon nanotubes (CNTs) nanocomposite coating with biomimetic golden spherical cactus surface structure (with micro-sphere and nano-thorns) was fabricated by electrostatic powder-spraying method. The superhydrophobic PSU-CNTs-FEP nanocomposite (PCFn) coating can be applied to different substrates such as aluminum plate, steel plate, glass plate, and steel pipe, which exhibited a maximum water contact angle all beyond 164 ± 1.5° and low slide angle of less than 5 ± 0.5°. The morphology, chemical composition and spherical cactus structure formation of the coatings were investigated. The electrostatic spraying and micro-phase separation promise a synergistic effect on promoting the superhydrophobicity, self-cleaning and high durability of PCFn coating. Moreover, the PCFn coating demonstrated unique multiple anti-corrosion effects, providing with air bubble corrosion protection, physical shielding and decreasing interfacial electronic agglomeration effect, which promises the wide applicability of the PCFn coatings in different engineering processes.

Biogas-residue-based mesoporous carbons with high adsorption capacity have been successfully synthesized via a facile template-free and one-step approach by sodium amide activation and applied in the removal of organic and inorganic pollutants in wastewater for the first time in this study. A “waste” and widely available resource, biogas residue, was utilized as carbon precursor. Different mesoporous carbons were prepared by direct co-milling and activation at various conditions, among which largest surface area of 1278 m2/g and maximum adsorption of 556 mg/g on methylene blue were achieved, respectively. It is also verified to possess superior adsorption capacity on typical organic pollutant phenanthrene (112 mg/g) and typical inorganic pollutant N/P element (N, 113 mg/g; P, 12 mg/g). The results show that the prepared mesoporous carbons possess high and universal adsorption performance toward both organic and inorganic pollutants in wastewater. Finally, the adsorption mechanism such as the relationship between the adsorption capacities and characterization results was also discussed. The low-valued raw materials, convenient procedure, energy conservation, minimum pollution and corrosion, high adsorption capacity show feasible manufacture in industry.

All-acrylic multigraft copolymers, poly(butyl acrylate)-g-poly(methyl methacrylate), synthesized using a facile grafting-through methodology, exhibit elongation at break (>1700%) and strain recovery behavior far exceeding those of any commercial acrylic (∼500%) and styrenic (∼1000%) triblock copolymers to date. One-batch anionic polymerization of methyl methacrylate (MMA) using the sec-butyl lithium/N-isopropyl-4-vinylbenzylamine (sec-BuLi/PVBA) initiation system gives PMMA macromonomers with quantitative yield, short reaction time, and using simple synthetic procedures. These new all-acrylic superelastomers and the simple synthetic approach greatly expand the range of potential applications of all-acrylic thermoplastic elastomers (TPEs).

Microwave absorption and catalytic activity have been synergistically integrated into a core/shell structured CNT/polyaniline (PANI) hybrid catalyst that enables localized heating on the catalyst surface and uplifts energy efficiency in the dehydration reaction of saccharides to 5-hydroxymethylfurfural (HMF). Results reveal that the integration of CNT and polyaniline significantly improves the overall saccharide conversion and HMF yield. The PANI shell thickness and morphology are controlled by both reactant feeding ratio and polymerization reaction rate. A thinner and rougher PANI shell is favourable to enhance the overall microwave absorption, improve heat transfer efficiency to catalyst surface and thus reaction efficiency. The highest energy efficiency of 7.6 mmol kJ−1 L−1 is reached in 10 min with CNT/PANI catalyst (30 wt% CNTs) and 19 W input power. Moreover, the packing of polyaniline shell on CNT core facilitates its separation from reaction mixture and effectively prevents catalyst loss. These catalysts show excellent recyclability that the catalyst activity can be completely recovered by a simple re-doping process in 1.0 M sulfuric acid. This work opens up a new window in microwave responsive catalyst design that enhances energy efficiency in saccharide-HMF conversion reactions and promotes the economic feasibility of such reactions in practice.

A novel class of ortho, para-alternating linked polyarenes is synthesized via catalyst-transfer Suzuki coupling polymerization with Pd2(dba)3/t-Bu3P/p-BrC6H4COPh as initiator. Through a series of kinetic studies and MALDI-TOF analysis, the polymerization is shown to proceed in a chain-growth manner. The optical and thermal properties for the ortho, para-alternating linked polyarenes exhibit unusual molecular weight dependence. Thus, the polymer with lower molecular weight (Mn = 6300 g mol−1) emits green fluorescence whereas the one with higher molecular weight (Mn = 13 800 g mol−1) emits blue fluorescence under UV (λ = 360 nm) irradiation. Furthermore, an all-conjugated block copolymer containing a polyfluorene block and the ortho, para-alternating linked block is also successfully prepared, in a one-pot procedure. These results can provide a pathway to obtain polyarenes with precisely controlled structures, hence, desirable properties.

Orientation immobilization of enzymes has attracted intensive interest owing to the retainable specific activity and stability. Specially, glycoprotein immobilized onto Concanavalin A (Con A) modified carriers induces the orientation of the enzyme. However, the effects of the interface properties of carriers and enzymes are still not well understood yet. In this study, we synthesized the activated porous poly (styrene- divinylbenzene) resin carriers with 30 nm pore sizes and 72 m2 g−1 specific surface areas and decorated with Con A. The resultant loading capacity of NP1 on Con A modified carriers was as high as 4.02 mg g−1 wet support as a result of strong affinity between the enzyme and Con A decorated on carriers. It was found that the acid resistance, thermal stability, reusability and degradation efficiency of the immobilized enzyme on Con A modified porous carriers were significantly improved. The reduction of Km from 18.40 ± 0.55 mg mL−1 to 17.19 ± 0.51 mg mL−1 illustrated the improved substrate affinity of HA-GA-ConA-NP1. Moreover, Con A-affinity NP1 exhibited the best operational stability that only 7% of its initial activity was lost even after 9 batches repeated reaction. This work demonstrates that surface property manipulation of porous carriers and its derivatives has great potential in efficient biocatalytic systems.

A novel N-doped porous graphitized biochar (NPGBC) with a large specific surface area (950.52 m2/g), partly graphitized structure, and high nitrogen (N) doping (3.61%) was prepared by co-carbonization of alfalfa, ferric chloride (FeCl3), and potassium hydroxide (KOH). This biochar was used as an adsorbent with excellent methylene blue (MB) (326.90 mg/g) and methyl orange (MO) (906.52 mg/g) sorption capacities from wastewater. The sorption of MB and MO by NPGBC followed pseudo-second-order kinetics and Sips models. Density functional theory (DFT) calculations showed that the pyrrole N and pyridine N played decisive roles in the elimination of MO. When the content of pyridine N was more than 6.67%, or the content of pyrrole N was more than 3.00% in the calculation model, it was conducive to the sorption of MO. The interactions between NPGBC and organic dyes included π–π stacking and electrostatic and hydrogen-bonding interactions. The above results provide important reference values for the preparation and application of high-efficiency organic dye adsorbents.

Partial deposition of carbon onto mesoporous TiO2 (C/TiO2) were prepared as supporting substrate for Pt catalyst development. Carbon deposition is achieved by in-situ carbonization of furfuryl alcohol. The hybrid catalysts were characterized by XRD, Raman, SEM and TEM and exhibited outstanding catalytic activity and stability in methanol oxidation reaction. The heterogeneous carbon coated on mesoporous TiO2 fibers provided excellent electrical conductivity and strong interfacial interaction between TiO2 support and Pt metal nanoparticles. Methanol oxidation reaction results showed that the activity of Pt-C/TiO2 is 3.0 and 1.5 times higher than that of Pt-TiO2 and Pt-C, respectively. In addition, the Pt-C/TiO2 exhibited a 6.7 times enhanced stability compared with Pt-C after 2000 cycles. The synergistic effect of C/TiO2 is responsible for the enhanced activity of Pt-C/TiO2, and its excellent durability could be ascribed to the strong interfacial interaction between Pt nanoparticles and C/TiO2 support.

In the past couple of decades, high thermally conductive fillers are extensively used to develop thermally conductive polymer based composites. Such conventional methods suffer from wide variety of problems especially related to fabrication, high-cost, poor mechanical properties etc. Though covalent bonds in single polymer chain can lead to very high thermal conduction, it is irony that bulk polymers are thermal insulators due to significant phonon scattering. In this work, we have shown how by engineering intermolecular interaction within the polymer chain, one can create continuous thermal network which in turn drives thermal conduction in polymer without using any traditional fillers. Thermal conduction pathways were introduced in a blend film of long chain polymer Poly (vinyl alcohol) (PVA) and short chain Poly (ethylene glycol) (PEG). Thermal conductivity enhancement of around 1.6 times of neat polymer was achieved. The critical factor responsible for thermal conduction in these films was found to be homogeneous distribution of “thermal bridges” formed by hydrogen bonding between PVA and short PEG chain. Reduction in thermal conductivity was observed when PVA blend film with longer PEG chain, which is mainly due to poor thermal bridges distribution and chain agglomeration. This work presents a fascinating yet promising non-conventional method to make thermally conductive polymer based material without using traditional fillers for thermal management applications.

Molecular level engineering of polymer or polymer blends has been recently demonstrated an effective strategy to regulate thermal conductivity. Such materials are of great interest to meet critical requirements of transparent, lightweight, flexible, and so on for thermal management in electronic applications. In this work, modulated polymer blends with poly(vinyl alcohol) (PVA) and biopolymers (lignin, gelatin) were designed and significantly enhanced thermal conductivity was achieved by tuning the intermolecular interaction among polymer components. The hydrogen bond interaction has been revealed as the major driving force that affects the polymer coil dimension in aqueous solution, the microstructure of coil–coil interaction in solid film, and thus, the thermal conduction. A solid relationship across molecular level interaction to macroscale thermal conduction is constructed via careful characterization of the coil size in liquid phase and assembled microstructure in solid phase. Appropriate integration...

Zeolitic Imidazolate Framework-8 (ZIF-8) membranes have shown great potential for effective separation of industrially important propylene/propane gas mixtures. In this work, we coated the silicalite seed nanoparticles on the anodic alumina oxide (AAO) substrate in order to increase membrane-substrate bonding. ZIF-8 membrane was synthesized on a silicalite-seeded AAO substrate by secondary growth method. It was found that high quality ZIF-8 membrane was fabricated due to strong attachment of silicalite seed crystals to AAO substrates through hydrogen bonding. Moreover, when ZnCl2 was used as the Zn source, the ZIF-8 layer was formed with larger ZIF-8 crystal size and a more intergrown surface than the layer in which ZnNO3 was used. An excellent propylene/propane separation factor of 170 was obtained in a silicalite-seeded ZIF-8 membrane with ZnCl2, which is twice that of a ZIF-8 membrane synthesized without the seeding process, and which is 3.6 times higher than a silicalite-seeded ZIF-8 membrane with ZnNO3.

In polymer composites, organosilanes are often used to modify the surface property of silica nanoparticles and improve the interfacial properties. Surface properties of the modified silica, such as grafting density and consequent surface energy, largely depend on the molecular structure of the silane. Achieving maximum interfacial bonding between the filler and polymer requires precise control of silica surface property. In this work, four silanes with similar molecular structure but different alkyl chain lengths, trimethoxy(propyl)silane, trimethoxy(octyl)silane, hexadecyltrimethoxysilane and trimethoxy(octadecyl)silane, are selected as model agents to study their roles in influencing silica surface property. The grafting density of silane on the silica is well controlled by regulating the reaction conditions. Three main surface characters, silane grafting density, surface energy and surface potential, are measured. More importantly, a linear relationship has been correlated when plotting grafting density vs. surface energy and grafting density vs. surface potential. Utilizing these relationships, a linear model has been developed to predict grafting density and surface energy by simply measuring surface potential. This model has been validated by both commercial silica and synthesized silica particles of different sizes.

All acrylic-based thermoplastic elastomers (TPEs) offer potential alternatives to the widely-used styrenic TPEs. However, the high entanglement molecular weight (Me) of polyacrylates, as compared to polydienes, leads to “disappointing” mechanical performance as compared to styrenic TPEs. In this study, triblock copolymers composed of alkyl acrylates with different pendant groups and different glass transition temperatures (Tgs), i.e. 1-adamatyl acrylate (AdA) and tetrahydrofurfuryl acrylate (THFA), were synthesized via reversible addition–fragmentation chain transfer (RAFT) polymerization. Thermal characterization of the resulting polymers was performed using differential scanning calorimetry (DSC), and the Tgs of both segments were observed for the block copolymers. This indication of microphase separation behavior was further demonstrated using atomic-force microscopy (AFM) and small angle X-ray scattering (SAXS). Dynamic mechanical analysis (DMA) showed that the softening temperature of the PAdA domains is 123 °C, which is higher than that of both styrenic TPEs and commercial acrylic based TPEs with poly(methyl methacrylate) (PMMA) hard block. The resulting triblock copolymers also exhibited stress–strain behavior superior to that of conventional all acrylic-based TPEs composed of PMMA and poly(n-butyl acrylate) (PBA) made by controlled radical processes, while the tensile strength was lower than for products made by living anionic polymerization.

Cotton fabric has been processed into hierarchically porous carbon with a two-step chemical-free method, i.e. carbonization in nitrogen and controlled thermal oxidation in air. By optimizing thermal oxidation temperature, large surface area of 777 m2/g could be achieved in cotton fabric derived carbon. The processed carbon remained the micron-meter tubular structure (same as cotton fiber), while meso-/micro-pores were also generated on tube wall. This uniquely structured porous carbon was then doped with nitrogen via a thermal pyrolysis process by using melamine as nitrogen source. The nitrogen doping level was controlled by adjusting the mass ratio of melamine and porous carbon. The nitrogen content in the doped porous carbon could reach up to 9.0 atom% without sacrificing the porous structure and surface area. The nitrogen doping significantly improved the electrochemical capacitance up to 180 F/g at 0.5 A/g, which is 74% enhancement compared to the nitrogen-free carbon (104 F/g). Both origin carbon and nitrogen doped carbon show excellent cycling stability that 95% of the capacitance could be remained after 5000 charge-discharge cycles.

Erosion is relevant to a variety of infrastructure problems such as bridge scour, roadway shoulder erosion, coastal erosion, and riverbank and slope stability. This research investigated the feasibility of using microbial-induced calcite precipitation (MICP) as an erosion countermeasure. MICP is a natural phenomenon in which calcite precipitation occurs as a consequence of microbial metabolic activity. The precipitated calcite modifies the soil fabric and provides an additional bonding force between soil particles. In this paper, a preliminary experimental study on the erosional behavior of MICP-treated sand is presented. A standard soil, Ottawa graded sand, was treated with a bacterium (Sporosarcina pasteurii) in a full-contact reactor-one in which the soil in a fabric mold was fully immersed in the bacteria and cementation solution. The morphologies and crystalline structures of the precipitated calcite in porous sediments were characterized using microscopic imaging techniques. The treated soil samples were tested in a flume to investigate the erosional behavior; both surface erosion and bridge scour tests were conducted. Although the untreated soil is highly erodible, the erosion of the treated sand was found to be negligible under the circumstances of the test; however, some concerns were raised regarding practical applications. Efforts will be made in the future to identify alternative treatment procedures that are more applicable to the field.

Surface functionalization of carbon nanofibers (CNFs) was carried out, i e, CNFs were firstly oxidized and then the surface was silanized by 3-Aminopropyltriethoxysilane (APTES) via an assembly method. A new kind of high wear resistance s-CNFs/epoxy composite was fabricated by in-situ reaction. FTIR spectroscopy was used to detect the changes of the functional groups produced by silane on the surface of CNFs. The tribological properties and microstructures of modified and unmodified CNFs/epoxy composites were studied, respectively. The expremental results indicate that APTES is covalently linked to the surface of CNFs successfully and improves the dispersion of CNF in epoxy matrix. The friction coefficients and the wear rates of s-CNFs/epoxy composites are evidently lower than those of u-CNFs/epoxy composites under the same loads. Investigations also indicate that abrasive wear is the main wear mechanism for u-CNFs/epoxy composite, with slight adhesive wear for s-CNFs/epoxy composite under the same sliding wear condition.

Converting nitrobenzene to freestanding polyaniline tube arrays has been successfully carried out in a "water-oil-water" triphasic reaction system, where catalytic reduction of nitrobenzene to aniline and aniline polymerization reactions were synergistically integrated. With optimized control over molecular diffusion and reaction at separate solid/liquid and liquid/liquid interfaces, polyaniline nanostructures could be synthesized with different morphologies. The paired molecular diffusion and reaction rate is revealed as the dominating factor that determines the feasibility of the reaction system to produce a patterned array structure. Slow molecular diffusion leads to a better ordered three-dimensional (3D) assembling structure. This work demonstrates a new approach to control 3D assembling structures with integrated control on diffusion and reaction across multiple liquid/liquid interfaces.

Hybrid electrodes with electroactive components on conductive substrates have been demonstrated to be an effective strategy to achieve high energy and power density in supercapacitors. However, the mismatch of interface property could be a huge hurdle to further improve energy storage performance and long-term stability. In this work, an interfacial metal seeding approach has been developed targeting strengthening of the interfacial interaction between electroactive NiCo2O4 nanostructure and carbon substrate as well as to promote electron transfer across the interface. By implanting low-concentration nickel (Ni) nanoparticles at the interface, the electrochemical capacitance of NiCo2O4 was boosted up to 2367 F/g at a current density of 1 A/g in a symmetric two-electrode configuration, which is about 2 times higher than the capacitance obtained from the electrode without metal seeds. The Ni seeds also contribute to an excellent cycling retention of >96% after 5000 cycles, where only 65% capacitance was ret...

The use of graphene oxide (GO) nanosheets for functional enzyme support has attracted intensive interest owing to their unique planar structure and intriguing physical and chemical properties. However, the detailed effects of the interface properties of GO and its functionalized derivatives on active biomolecules are not well understood. We immobilize nuclease P1, a common industrial nucleic acid production enzyme, on pristine and amino poly(ethylene glycol) (PEG-NH2) modified GO nanosheets with interface property heterogeneity using two approaches, physical adsorption and chemical crosslinking. It is demonstrated that nuclease P1 could be stable immobilized on the surface of pristine GO by physical adsorption and on the edge of modified GO nanosheets by chemical crosslinking. The resultant loading capacity of nuclease P1 on pristine GO is as high as 6.45mg/mg as a consequence of strong electrostatic and hydrophobic interactions between the enzyme and carrier. However, it is determined that the acid resistance, thermal stability, reusability and degradation efficiency of the immobilized enzyme on PEG-NH2-modified GO are obviously improved compared to those of the enzyme immobilized on pristine GO. The enhanced catalytic behavior demonstrates that GO and its derivatives have great potential in efficient biocatalytic systems.

Whereas poly(3-alkyl-2,5-thiophene)s (P3AT), with many potential applications, have been extensively investigated, their ortho-connected isomers, poly(5-alkyl-2,3-thiophene)s (P5AT), have never been reported because of the difficulty in their syntheses. We herein present the first synthesis of regioregular P5AT via controlled Suzuki cross-coupling polymerization with PEPPSI-IPr as catalyst, affording the polymers with tunable molecular weight, narrow polydispersity (PDI), and well-defined functional end groups at the gram scale. The helical geometry of P5AT was studied by a combination of NMR, small-angle X-ray scattering (SAXS), and scanning tunneling microscopy (STM). Particularly, the single polymer chain of poly(5-butyl-2,3-thiophene) (P5BT) on highly oriented pyrolytic graphite (HOPG) substrates with either M or P helical conformation was directly observed by STM. The comparison of UV–vis absorption between poly(5-hexyl-2,3-thiophene) (P5HT) (λ = 345 nm) and poly(3-hexyl-2,5-thiophene) (P3HT) (λ = 45...

Depolymerization and modification of lignin have been achieved simultaneously in a one-pot chemical reaction. Two heteroelement-rich modifiers, imidazol-1-yl phosphonic dichloride and 1H-1,2,4-triazol-1-yl phosphonic dichloride, were selected to react with lignin in this work. The modified lignin (m-lignin) is demonstrated as an effective lubricating additive for [choline][amino acid] ([CH][AA]) bioionic liquids. Different characterization techniques have been utilized to study the lignin depolymerization, reaction between lignin and modifiers and m-lignin/[CH][AA] interaction. The effect of the molecular structure of the modifiers on the rheological and tribological properties of m-lignin/[CH][AA] lubricants was systematically investigated. Density function theory is used to calculate the electronic structure of lignin, m-lignin, and [CH][AA]. The atomic natural charge analysis revealed the most negative charge on nitrogen bonded to a phosphorus atom and the strongest capability of forming hydrogen bondi...

Myo-inositol (MI) as a major intracellular osmolyte can be accumulated to protect cells from a variety of stress. The present study was to evaluate the effects of dietary MI on growth, osmotic response and transcriptional response in the liver of euryhaline fish Oreochromis mossambicus under long-term salinity stress. Five isonitrogenous and isolipidic diets were formulated to include 0 (MI0), 200 (MI200), 400 (MI400), 800 (MI800) and 1600 (MI1600) mg/kg MI. In this study, dietary 400 mg/kg MI significantly increased the weight gain and specific growth rate of O. mossambicus compared with the group without dietary MI supplementation under salinity stress. Moreover, dietary MI decreased serum glucose and insulin levels of fish under long-term salinity stress. Fish fed 400 mg/kg MI supplementation had significantly higher serum cortisol, sodium (Na+) and chloride ion (Cl−) than those fed a diet without MI supplementation. A total of 132.17 million and 115.8 million clean reads were obtained from the 0 mg/kg MI (MI0) and 400 mg/kg (MI400) MI group respectively. Compared with the MI0 group, the expression of 704 genes was significantly changed (521-up and 183-down) in the MI400 group under long-term salinity stress. Transcriptome results indicate that myo-inositol can regulate lipid and pyruvic acid metabolism, increase phospholipid synthesis-related mRNA levels and improve antioxidant properties of O. mossambicus under long-term salinity stress. This study suggests that optimum MI supplementation is 400 mg/kg in the diet based on weight gain against dietary MI and this result provides a nutritional solution for tilapia to cope with salinity stress.

This study was to evaluate the relationship between myo-inositol synthesis and carbohydrate metabolism in Mozambique tilapia (Oreochromis mossambicus). Fish were immediately transferred from 0 psu (practical salinity units, the control) to 20 psu for 96 h with 60 fish in each group. Compared with the control group, the volume of the mitochondria-rich cell in the gills of O. mossambicus was significantly increased by acute hypersaline stress. The osmotic pressure and the contents of Na+, K+ and Cl− in the serum were significantly increased in the 20 psu group. Moreover, fish in the 20 psu group had significantly higher activities of glutathione peroxidase and superoxide dismutase and a higher malondialdehyde content than the control in the liver. Salinity stress significantly increased the serum glucose but decreased the liver glycogen. The activities of glucokinase and phosphofructokinase in the liver and gills were significantly higher in the 20 psu group, indicating that glycolysis could be significantly enhanced by salinity stress. The activities of glucose-6-phosphate synthase and phosphoenolpyruvate carboxykinase in the liver were significantly decreased by salinity stress. The expressions of myo-inositol-1-phosphate synthase and myo-inositol monophosphatase were significantly up-regulated in the gills and kidney. However, the expressions of these two genes were significantly down-regulated in the liver. The myo-inositol content in the gills, kidney and liver in the 20 psu group were significantly increased by salinity stress. This study indicates that salinity stress can impair the gill structure and reduce the antioxidant capacity of O. mossambicus. The changes in MI biosynthesis and carbohydrate metabolism could be an effective strategy to alleviate the adverse effect of salinity stress.

Double-percolated thermally conductive polymer composites comprising of polypropylene (PP), poly (methyl methacrylate) (PMMA), and boron nitride (BN) were successfully produced by melt compounding. The effects of BN platelets sizes on morphology and thermal conductivity (TC) were investigated by mixing three different sizes BN, namely 16, 30 and 180 μm with PP and PMMA. The obtained results demonstrate that for all the sizes, BN platelets were either in the PMMA phase or at the interface, and the ternary composites with high filler loadings showed enhanced TC compared to the corresponding binary systems. It is shown that smaller BN platelets led to finer morphology, which caused more interfaces and consequently more phonon scattering and lower TC of the system. Finally, we show for the first time that there is a direct scaling between particle size, mechanical properties and TC. This work proved the advantage of using double-percolated structure to improve TC of polymer composites and provided a better understanding of the filler size effects on the morphology and TC of ternary systems.

Lignin, one of the most naturally abundant polymers, has been successfully incorporated into ethylene glycol (EG) and poly(ethylene glycol) (PEG) in this work and fortified lubricating properties were achieved in EG/lignin and PEG/lignin. The molecular interaction between lignin and EG (or PEG) has been revealed as hydrogen bonding, which serves as the dominating factor that determines the thermal, rheological, and tribological properties of the mixed systems of EG/lignin and PEG/lignin. The physicochemical properties of the mixed lubricants are tightly related to the state of internal hydrogen bonding (EG–EG, PEG–PEG, EG–lignin, PEG–lignin, and lignin–lignin) and are well correlated to their lubrication properties. Generally, larger lignin fractions lead to better lubricating performance in both EG and PEG systems. Lignin liquefaction in PEG has been addressed by catalytic degradation with the presence of sulfuric acid, which was then neutralized by triethanolamine for lubricant development. Lignin in PE...

Ionic liquid lubricants or lubricant additives have been studied intensively over past decades. However, ionic grease serving as lubricant has rarely been investigated so far. In this work, novel protic [triethanolamine][oleic acid] and aprotic [choline][oleic acid] ionic greases are successfully synthesized. These ionic greases can be directly used as lubricants without adding thickeners or other additives. Their distinct thermal and rheological properties are investigated and are well-correlated to their tribological properties. It is revealed that aprotic ionic grease shows superior temperature- and pressure-tolerant lubrication properties over those of protic ionic grease. The lubrication mechanism is studied, and it reveals that strong physical adsorption of ionic grease onto friction surface plays a dominating role for promoted lubrication instead of tribo-chemical film formation.

Superamphiphobic and electroactive composite coating on aluminum substrate was successfully fabricated by integrating epoxy, polyaniline (PANI), fluorinated ethylene propylene, carbon nanotubes and SiO2 nanoparticles into a two-layer coating configuration with nano/micro hierarchical surface structure. The composite coating demonstrates strong adhesion, excellent wear resistance and durable anti-wettability. The electrochemical tests demonstrated significantly enhanced anticorrosion performance by surface barrier effect of the superamphiphobic coating and redox catalytic capability of embedded electroactive PANI. The design principle of the multi-functional coatings will definitely benefit the advancement of durable anti-corrosive coatings and the achieved superior properties will promise a wider engineering applications in petroleum related industries.

Engineering polymers with high glass transition temperature have been widely used in dynamic friction systems by oil or solid lubrication. However, in high-load systems, oil lubrication is less efficient due to the viscosity decrease at higher temperatures induced by friction heat. [Bmim][PF6] ionic liquid was used and compared with traditional L-HM46 oil and solid PTFE. Taking advantage of high [Bmim][PF6] viscosity, strong steel-[Bmim][PF6] but poor PEEK-[Bmim][PF6] interaction, the [Bmim][PF6] lubricated PEEK/steel slide falls in hydrodynamic lubrication and elastohydrodynamic lubrication region under 150–1500 N. While the oil and PTFE both failed to lubricate under 800 N.

Mesoporous TiO 2 microparticles featuring distinct, well-defined pore sizes (3.7–40 nm) were used for investigating the effect of geometrical topography and surface chemistry on the immobilization of adenosine deaminase (ADA). We determined that the pore size of the microparticles can be tuned by varying the post-heat-treatment process. The ADA-adsorption properties of microparticles displaying distinct geometrical topographies were compared, and the relations between pore sizes and the levels of protein loading and enzyme activity were investigated. Although the specific surface area of large-pore microparticles was smaller than that of microparticles harboring small pores, carriers derived from large-pore microparticles exhibited comparatively superior enzyme loading; an overall enzyme loading of 13.5 mg/g was achieved in the case of TiO 2 carriers featuring 20 nm intra-particle pores. In order to strengthen operational stability, surface modification with (3-aminopropyl) triethoxysilane (APTES) and crosslinking with glutaraldehyde were performed; the operational stability of ADA immobilized on TiO 2 –APTES microparticles featuring various pore sizes was considerably higher than that of ADA immobilized on blank TiO 2 . Thus, both the geometrical topography and surface chemistry of mesoporous TiO 2 microparticles and ADA were crucial for achieving high biocatalysis activity and operational stability.

In this study, hydrogen-bonding interactions between polyvinylalcohol (PVA) and graphene oxide (GO) were utilized as the driving force to fabricate organic/inorganic PVA nanocomposite films with homogeneous dispersion of GO. The nanomechanical and nanotribological performances of pure PVA and PVA/GO films were investigated by using nanoindentation technique. The results demonstrated that the incorporation of 0.5 wt% GO in PVA gives the highest improvement in nanomechanical and nanotribological properties. Compared to pure PVA, the elastic modulus and hardness of 0.5 wt% GO/PVA were notably increased by 122.8% and 64.5%, respectively. Furthermore, the film showed self-lubrication effect and enhanced anti-scratch performance. TGA study reveals an enhanced maximum decomposing temperature of 68.4 °C with the addition of 0.5 wt% GO in PVA. The stability of hydrogen bonding between PVA and GO accompanied with the formed organic/inorganic assembled lamellar micro-structure of PVA/GO films is the main reason for the distinct improvements in nanomechanical, nanotribological and thermal properties of PVA/GO nanocomposite films.

The graphene-covered mesoporous TiO 2 ( S BET > 90 m 2 g −1 ) were successfully prepared by using graphene oxide (GO) as graphene source via one-step hydrothermal reduction, and then were prepared supported NiMo catalysts for hydrodesulfurization (HDS) of dibenzothiophene (DBT). The active species were incorporated by incipient impregnation. Compared with the unmodified NiMo/TiO 2 catalyst, all modified catalysts exhibited higher HDS activity under mild conditions of 280 °C, 2.0 MPa, liquid hourly space velocity of 4 h −1 and hydrogen/feed ratio of 400 (V/V). Among of them, the catalyst with the appropriate mass ratio of rGO/TiO 2 (0.5) showed the highest DBT conversion of 99.9%. The prepared catalysts were characterized by various techniques (N 2 adsorption-desorption, XRD, Raman, Pyridine FT-IR, NH 3 -TPD, H 2 -TPR, CO uptake, SEM and TEM). The enhanced HDS activity can be ascribed to (i) The incorporation of rGO (reduced graphene oxide) induces proper enhanced Lewis acidity of the modified catalysts, which promotes the adsorption of DBT molecules and facilitates the hydrogenation route. (ii) The introduction of rGO changes the HDS product (H 2 S) desorption behaviors, accelerating H 2 S desorption rate from catalyst surface and promoting the efficiency of catalyst immediately.

The phase equilibria of the Sn-Zn-Sb ternary system at 400 and 500 °C were experimentally determined by electron probe microanalyzer, x-ray diffraction and differential scanning calorimetry. In this study, the ternary compound of (Zn,Sn)Sb is confirmed at 400 and 500 °C. Additionally, a liquid phase region is found at 400 °C with composition ranges of 9.09-12.86 at.% Zn and 31.47-34.22 at.% Sn, which becomes a prolongation of the main liquid as the temperature is raised to 500 °C.

Hierarchically porous tubular carbon (HPTC) with large surface area of 1094 m(2)/g has been successfully synthesized by selectively removing lignin from natural wood. No templates or chemicals are involved during the process. By further KOH activation, surface area of activated HPTC reaches up to 2925 m(2)/g. These materials show unprecedented high adsorption capacity toward organic dyes (methylene blue, 838 mg/g; methyl orange, 264 mg/g) and large electrochemical capacitance of200 F/g. The sustainable feature of the wood precursor and demonstrated superior adsorption and energy storage properties allow promising applications of the processed materials in energy and environmental related fields.