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[Display omitted] • Date seed derived biochar production via slow pyrolysis. • Chemically modified activated carbons are derived from date seed using H 2 SO 4 as an activating agent. • Capacitive performance is highly affected by the ordered structure of biochar-based materials. The main aim of this research work is to make activated carbon (AC) materials based on biochar obtained from date seeds via pyrolysis and activated with H 2 SO 4. The study aimed to assess the potential of these biochar-based materials for energy storage in supercapacitor by investigating the impact of different activation temperatures on their electrochemical performance in an alkaline electrolyte. The focus was on identifying the most efficient material. Results from Raman Spectroscopy and XRD analysis revealed that sample DSAC-700 exhibited more ordered domains and suitable storage sites compared to the other biochar-based materials. Measured value of the ratio of intensity of D & G band (I D /I G) for DSBC-600, DSAC-700, DSAC-800, and DSAC-900 were 1.13, 0.83, 1.06, and 1.04, respectively. The lowest value of (I D /I G) for DSAC-700 indicated a higher ordered graphitic plane, resulting improved conductivity and diffusion of ions within the aligned graphitic domains, which positively impacted the electrochemical performance. Samples DSAC-700 showed 487.5 F/g specific capacitance at 1 A/g current density. Galvanic charge and discharge trends also showed that DSAC-700 had higher charge storage ability with less discharge. The biochar-based materials (BC and ACs) derived from DS showed promise as materials for energy storage applications, and they represent a step towards clean energy. [ABSTRACT FROM AUTHOR]

The main object of this research is chemical modification of the nanofibrillated cellulose (NFC) surface with a phenanthridinium silane salt to develop durable non-leaching antibacterial surface. Initially, (3-trimethoxysilylpropyl) phenanthridinium iodide (TMSPhI) as an antibacterial agent was synthesized using (3-chloropropyl trimethoxysilane) (CPTMS) and phenanthridine in the presence of potassium iodide. Subsequently, NFC was cationized by reaction of its hydroxyl groups with the trimethoxysilane group of TMSPhI to prepare the modified sample (NFC-TMSPhI). The synthesized TMSPhI was characterized by FT-IR, 1 H and 13 C NMR spectroscopies. The modified NFC samples were also characterized by FE-SEM/EDX, XRD, TGA, elemental analysis, contact angle measurement, FT-IR, UV–Visible and fluorescence spectroscopies. The obtained NFC–TMSPhI samples presented fluorescence property at the maximum emission wavelength in the range of 539-549 nm. Additionally, the antibacterial activity of the modified samples were evaluated quantitatively against Gram-positive ( S . aureus ) and Gram-negative ( E . coli ) bacteria. All the modified samples displayed promising results with at least bacteriostatic effect or bactericidal properties. Finally, the cytotoxic effect of the modified sample on human dermal fibroblasts (HDFs) and two cancer cell lines (MCF-7 and Hela) was investigated that showed dose- and surface charge-dependent toxicity. [ABSTRACT FROM AUTHOR]

Cellulose nanowhiskers (CWs) extracted from cotton fibers were successfully modified with distinct anhydrides structures and used as additives in poly(vinyl alcohol) (PVA) nanocomposite films. The surface modification of CWs was performed with maleic, succinic, acetic or phthalic anhydride to compare the interaction and action the carboxylic groups into PVA films and how these groups influence in mechanical properties of the nanocomposites. CWs presented a high degree of crystallinity and good dispersion in water, with average length at the nanoscale. The addition of specific amounts (3, 6 and 9 wt.%) of modified-CWs increased up to 4.4 times the storage modulus (PVA88-CWSA 9 wt.%), as observed from dynamic mechanical analysis (DMA), compared to the bare PVA films. A significant increase in mechanical properties such as tensile strength, elastic modulus, and elongation at break showed a close relationship to the amount and chemical surface characteristics of CWs added, suggesting that these modified-CWs could be explored as reinforcement additives in PVA films. [ABSTRACT FROM AUTHOR]

In practical applications, cyclic heating and high temperature will worsen the stability of nanofluids. To enhance the practical application of nanofluids for mid-temperature solar collectors, WO 2.9 nanoparticles were modified by hexadecyl trimethoxysilane and the corresponding heat-transfer-oil-based nanofluids was prepared for mid-temperature solar collecting. Stability of nanofluids was evaluated by static observation, Zeta potential and thermal shock experiments at 200 °C. The results showed that nanofluids with mass fractions up to 4 wt% remained static stability beyond 5 weeks and 0.85 wt% nanofluids had thermal shock stability at 200 °C for over 2 weeks. This excellent performance makes them a suitable long-term working fluid medium for solar mid-temperature collectors. The increase in thermal conductivity also enhances the thermal performance of systems in industrial processes. It's noteworthy that preliminary exploration of the cyclic thermal stability mechanism of nanofluids provides a reference for further research on thermal shock stability of nanofluids in actual services. [Display omitted] • Hexadecyl trimethoxysilane is used to improve the stability of nanofluids. • The self-condensation products are beneficial to the stability of nanofluids. • Nanofluids with mass fractions up to 4% remain stable after 5 weeks of resting. • The nanofluids remain stable after thermal shock experiment at 200 °C for 2 weeks. • The nanofluids can be used in solar mid-temperature collectors for a long time. [ABSTRACT FROM AUTHOR]

[Display omitted] • Stable binary nanofluids were prepared by surface modification with coupling agent. • Working condition was simulated by interval heating as well as magnetic stirring. • Thermal conductivity of nanofluids decreased within 3.5% after standing for 14 days. • Nanofluids remain stable after cyclic thermal shock experiment at 90 ℃ for 14 days. Binary nanofluid has excellent heat transfer performance and spectral selective absorption characteristic. However, when nanofluid is applied to actual systems, it is subject to severe thermal shock, which leads to quick agglomeration and therefore deterioration of the performances. This study aims to investigate the stability of tungsten oxide (WO 2.9)-silicon carbide (SiC) binary nanofluid in actual service environment. The surface of nanoparticles was chemically modified by the coupling agent method, and the process was optimized. Then, the binary nanofluid was prepared with the optimal process of unitary nanofluid and the improved two-step method. And the actual working condition was simulated by interval heating as well as magnetic stirring. Finally, the preparation process was optimized further from the aspects of particle size, particle concentration, and thermal shock temperature. The results show that the binary nanofluid prepared by the optimum preparation process can maintain great stability after cyclic thermal shock experiment at 90 ℃ for 14 days, which put a foundation for the application of binary nanoparticles into solar beam splitting and enhance its practicality. [ABSTRACT FROM AUTHOR]

One of the techniques for a reduction in particle cohesiveness is the admixing of nano-particles. However, the mechanism of cohesiveness reduction has not yet been clarified. In this study we focused on a compressed packing fraction as one of the values reflecting the cohesiveness and flowability in a compressed particle flow. In order to estimate the mechanism of the reduction, the effects of an adhesive force of admixed particles on the packing fraction were investigated experimentally. In the experiments, silica particles with 397 and 8 nm diameters were used as the main and the admixed particles, respectively. The surfaces of the admixed particles were modified chemically in order to vary their adhesive force with maintaining morphological and mechanical characteristics. At more than 2.0% mixing mass ratios, the decreasing rate with increasing the mass ratio in net difference value of packing fraction for modified admixed particles was smaller than that for the raw particles. A calculation of the packing fraction of the admixed particles in the voids of main particles revealed that difference of the decreasing rates could be attributed to the difference of cohesivenesses between raw and modified admixed particles. The maximum packing fraction achieved by the modified admixed particles was lower than that achieved by the raw admixed particles. However, when a mixture of main and admixed particles was packed by tapping, the packing fraction with modified admixed particles was higher than that with raw admixed particles. This implied that the adequate adhesive force of admixed particles is different by the applied compression force value. [ABSTRACT FROM AUTHOR]

The conversion of the cellular prion protein (PrPC) into aggregated ß-oligomeric (PrPß) and fibril (PrPSc) forms is the central element in the development of prion diseases. Here we report the first use of isotopically-coded hydrogen peroxide surface modification combined with mass spectrometry (MS) for the differential characterization of PrPC and PrPβ. 16O and 18O hydrogen peroxide were used to oxidize methionine and tryptophan residues in PrPC and PrPβ, allowing for the relative quantitation of the extent of modification of each form of the prion protein. After modification with either light or heavy forms of hydrogen peroxide (H2 16O2 and H2 18O2), the PrPC and PrPβ forms of the protein were then combined, digested with trypsin, and analysed by LC-MS. The 18O/16O signal intensity ratios were used to determine the relative levels of oxidation of specific amino acids in the PrPC and PrPβ forms. Using this approach we have detected several residues that are differentially-oxidized between the native and β-oligomeric prion forms, allowing determination of the regions of PrPC involved in the formation of PrPβ aggregates. Modification of these residues in the β-oligomeric form is compatible with a flip of the β1-H1-β2 loop away from amphipathic helices 2 and 3 during conversion. Biological significance: Surface modification using isotopically-coded hydrogen peroxide has allowed quantitative comparison of the exposure of methionine and tryptophan residues in PrPC and PrPß forms of prion protein. Detected changes in surface exposure of a number of residues have indicated portions of the PrP structure which undergo conformational transition upon conversion. This article is part of a Special Issue entitled: Can Proteomics Fill the Gap Between Genomics and Phenotypes? [ABSTRACT FROM AUTHOR]

Abstract: Block co-polymer (BCP) lithography is becoming an established technique for patterning beyond optical lithography limitations. It is based on combining the intrinsic property of block co-polymers to phase separate at the molecular scale with the capabilities of conventional top-down lithographic methods for patterning surfaces. Guiding the self-assembly of block co-polymers by surface chemical modification is one of the most used processes to drive the self-assembly in a convenient way. It consists on using lithography and oxygen plasma to create different wettability regions on a polymer brush grafted on the surface. However, the optimal conditions for obtaining a good guiding pattern in chemical surface modification are difficult to find since the ultimate mechanism that causes the guiding is not completely known. We present an investigation about the use of hydroxyl-terminated polystyrene (PS-OH) as a single polymer brush layer for multiple patterning directed self-assembly DSA of PS/PMMA block co-polymers. We achieve pattern multiplication with density increase factors up to ×12 and we demonstrate pattern transfer to silicon. [Copyright &y& Elsevier]

Abstract: Control over biointerfacial interactions in vitro and in vivo is the key to many biomedical applications: from cell culture and diagnostic tools to drug delivery, biomaterials and regenerative medicine. The increasing use of nanostructured materials is placing a greater demand on improving our understanding of how these new materials influence biointerfacial interactions, including protein adsorption and subsequent cellular responses. A range of nanoscale material properties influence these interactions, and material toxicity. The ability to manipulate both material nanochemistry and nanotopography remains challenging in its own right, however, a more in-depth knowledge of the subsequent biological responses to these new materials must occur simultaneously if they are ever to be affective in the clinic. We highlight some of the key technologies used for fabrication of nanostructured materials, examine how nanostructured materials influence the behavior of proteins and cells at surfaces and provide details of important analytical techniques used in this context. [Copyright &y& Elsevier]

Abstract: In recent years herbicides and heavy metals have surfaced as the most significant environmental pollutants due to rapid industrialization and an increase in population worldwide. While quite effective and efficient, some of the treatment methods, for the removal of these environmental pollutants, involve high operating and maintenance cost along with producing toxic byproducts. Thus, biosorbents have become an attractive alternative to other well established methods. In this study red algae, Gracilaria verrucosa was investigated as a potential biosorbent for the phenoxyalkanoic acid herbicide 2,4-D and the heavy metal Cr(VI). The sorption capacity was found to be 22.3mgg−1 and 113.2mgg−1 respectively. In order to establish the efficiency of G. verrucosa as a biosorbent, sorption tests were conducted with different environmental and process parameters. This study verified that the acid treated biomass, indicates a gradual 47% and 21% increment for 2,4-D and Cr(VI) sorption compared with alkali, formaldehyde, and alcohol treatment. The sorption tests of the red algae G. verrucosa; offer two times more heavy metal removal when compared with low cost biosorbents. Two and three parameter equilibrium models were used to describe the sorption process. Experimental and modeling studies indicate that the sorption process of the investigated sorbents is physisorption with monolayer and endothermic characteristics. Also, surface properties of G. verrucosa were investigated and the effects of the surface active groups were identified. For 2,4 D sorption hydroxyl, carboxyl, and amine and for Cr(VI) sorption hydroxyl, carbonyl, and amino groups were identified as the important surface active groups. [Copyright &y& Elsevier]

Abstract: Surface modification of polymeric films is a way to obtain final products with high performance for many specific and ad hoc tailored applications, e.g. in functional packaging, tissue engineering or (bio)sensing. The present work reports, for the first time, on the design and development of surface modified ethylene–acrylic acid copolymer (EAA) films with polyaniline (PANI), with the aim of inducing electrical conductivity and potentially enable the electronic control of a range of physical and chemical properties of the film surface, via a new “grafting from” approach. In particular, we demonstrate that PANI was successfully polymerized and covalently grafted onto flexible EAA substrates, previously activated. The final hybrid materials and the corresponding intermediates were fully characterized via FTIR, XPS, SEM–EDAX, mechanical and electrical tests. The mechanical properties of the films are not detrimentally affected by each treatment step, while a significant increase in electrical conductivity was achieved for the new hybrid materials. [Copyright &y& Elsevier]

Abstract: Organosilane self-assembled monolayers (SAMs) with perfluoroalkyl groups (R f) on glass surfaces were used for arraying proteins and cells on chips. Quartz crystal microbalance measurements confirmed the inhibition of protein adsorption on R f-SAM-modified surfaces and showed efficient adsorption on hydroxyl-, carboxyl-, and amino group-modified surfaces. The characteristics of R f-modified surfaces were evaluated using solvent contact angle measurement and Fourier transform infrared (FTIR) spectroscopy. The R f surface was highly water- and oil-resistant, as inferred from the contact angles of water, oleic acid, and hexadecane. Specific peaks of IR spectra were detected in the region from 1160 to 1360cm−1. Etching with dry plasma completely exfoliated the R f-SAM, exposing the underlying intact glass surface. Modification conditions were optimized using contact angle and FTIR measurements. After dry plasma processing, the contact angles of all solvents became undetectable, and the IR peaks disappeared. Micrometer scale protein and cell patterns can be fabricated using the proposed method. Protein adsorption on micropatterned R f-SAM-modified chips was evaluated using fluorescence analysis; protein adsorption was easily controlled by patterning R f-SAM. PC12 and HeLa cells grew well on micropatterned R f-SAM-modified chips. Micropatterning of R f-SAM by dry plasma treatment with photolithography is useful for the spatial arrangement of proteins and cells. [Copyright &y& Elsevier]

In the second part of the article, the subtractive processes—laser etching and cutting—in the presence of liquid water will be reviewed; but the rarely used methods of water assisted/underwater laser processing, such as welding, silicon wafer breaking, surface modification of polymers, pulsed laser deposition, particle formation and water mask defined microstructures fabrication, will also be described. Etching and cutting under water provide better tolerances and smaller heat-affected zone widths and avoid the re-deposition of debris. Irradiation under water results in increased wetting of fluoropolymers, and laser ablation in water vapor provides deposition of highly crystalline hydroxyapatite coatings. Laser irradiation of solid targets in water has been used to fabricate Ag, Au, Ni, Cu and carbon nanoparticles. The results of an original study on the formation of free-standing high aspect ratio Pb(ZrxTi1−x)O3 microplates fabricated by laser irradiation of Pb(ZrxTi1−x)O3 ceramics in water are also reported. The platelets were up to 60 μm in diameter and 50–160 nm in thickness. The use of neutral liquids other than water and some medical applications of underwater/water-assisted laser light driven processes will also be briefly reviewed. [Copyright &y& Elsevier]

Nowadays, metal oxide nanoparticles (NPs) have been applied in various fields of nanotechnology including catalysis of chemical reactions, drug delivery, water treatment, textile industries, polymer composites, adhesives, and coatings. The greatest challenge in relation to metal oxide NPs is high tendency to aggregation. Chemical surface modification of metal oxide NPs has gained widely interest to control of dispersion and aggregation of NPs. Silane modifiers are one of the most important bifunctional modifiers that are frequently used for surface treatment of metal oxide NPs. In this review paper, we first focus on the synthesis, surface thermodynamic properties, surface modification techniques, and kinetic of silanization reaction of metal oxide NPs. Then, the recent development in using silane modifiers for treatment of metal oxide NPs in various applications were investigated. It was found that the unmodified NPs have high surface energy and are thermodynamically unstable. The thermodynamic properties of NPs including G m s , H m s , and S m s increase with decreasing the particle size. Aggregation phenomena is the simple way to reduce the excess surface energy of NPs that leads to an increase in particle size. Therefore, the chemical surface modification of NPs using silane modifiers can be used as an effective method for the prevention of NPs agglomeration and improvement of NPs stability. Unlabelled Image • A general overview of the synthesis techniques of metal oxide nanoparticles. • Study of surface thermodynamic properties of nanoparticles. • Investigation of kinetic of silanization reaction. • Improvement of the surface properties of metal oxide nanoparticles by using silane modifiers. • A glimpse of potential application of silane-modified metal oxide nanoparticles. [ABSTRACT FROM AUTHOR]

Heavy metal adsorption from aqueous solution onto modified biochar derived from date seed biomass was investigated. Modification methods included pre-treatment of the biomass prior to pyrolysis using NaOH and HCl (labelled as DSB-PB and DSB-PA respectively) and post–treatment of the biochar pyrolyzed at 550 °C for 3 h with NaOH and HCl (labelled as DSB-BW and DSB-AW respectively). Modified biochars were compared to unmodified one in terms of their surface chemistry, morphology, metal uptake, and adsorption kinetic behaviour. Scanning electron microscopy images show that acid and base treatment enhanced the biochar porous structure. Fourier-transform infrared spectroscopy revealed that acid treatment had enriched the functional groups such as C C, C O, C O, and phenolic groups on the biochar surface which further facilitated metal ions adsorption. Alkali treatment had less significant impact on the biochar surface functional groups. Modification improved the adsorption capacity for all metals. Most notably, DSB-PA biochar showed the highest adsorption capacities of 0.911, 0.705, and 0.692 mmol g−1 for Pb2+, Cu2+, and Ni2+ respectively. Compared to the unmodified biochar, the adsorption capacities of DSB-PA for Pb2+, Cu2+, and Ni2+ increased by 27%, 66% and 98%, respectively. Sips model adequately described the adsorption isotherms indicating heterogeneous adsorption systems. Adsorption rates of metal ions onto the DSB-PA were fast with almost 94% of the total amount of metals adsorbed within the first hour compared to 3–6 h for unmodified biochar. Pre-treatment of biochar with HCl is an economical method to produce an effective low-cost adsorbent with low environmental impact. [ABSTRACT FROM AUTHOR]