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Abstract In this study, Wood Plastic Composites (WPCs) were produced from post-consumer bulky wastes of recycled plastic and wood in order to minimize waste, decrease environmental effects of plastics, reserve natural resources, and support circular economy for sustainable production and consumption. Five different types of polypropylene (PP) or polyethylene (PE) based recycled plastics and wood obtained from urban household bulky wastes were used in the production of recycled WPC composites, r-WPCs. Virgin WPC (v-WPC) and r-WPC compounds were prepared with wood flour (WF) and maleic anhydride grafted compatibilizer (MAPP or MAPE) to evaluate the effect of recycled polymer type and compatibilizer on the mechanical properties. It was found that tensile strength properties of r-WPCs produced from recycled PP (r-PP) were higher than that of the r-WPCs produced from mixed polyolefins and recycled PE. r-WPCs containing anti-oxidants, UV stabilizers, and compatibilizer with different WF compositions were produced from only recycled garden fraction PP (PPFGF) to determine the optimum composition and processing temperature for pilot scale manufacturing of r-WPCs. Based on tensile, impact, flexural, and water sorption properties of r-WPC compounds with different formulations, the optimum conditions of r-WPC compounds for industrial manufacturing process were determined. Surface morphology of fractured surfaces as well as tensile, flexural and density results of r-WPC compounds revealed the enhancement effect of MAPP on interfacial adhesion in r-WPCs. r-WPC products (crates and table/chair legs) based on bulky wastes were produced using an injection molding process at industrial scale by using 30 wt% WF-filled r-WPC compound. This study demonstrated that r-WPC compounds from recycled bulky plastic and wood wastes can be used as a potential raw material in plastic as well as WPC industry, contributing to circular economy. Graphic Abstract

In this study, we present the ethyl esters biodiesel production from Nannochloropsis oculata and Spirulina sp. microalgal lipids on 60 wt% CaO on Al2O3 catalyst at 50 degrees C and 1.0 atm. The activity of the catalyst was studied as a function of ethanol:lipid molar ratios, catalyst amounts and reaction times. It was found that 6 wt% of the lipids as catalyst amount resulted in 59% biodiesel yield in 30 min at 12 of ethanol:lipid molar ratio whereas 90-99% biodiesel yield was obtained at 24 and 48 of ethanol:lipid molar ratios. In order to achieve 90-99% yields, the basic strength was found to be weak and to be in the form of bi-carbonate, whereas high basicity was not necessary. Besides, pure CaO and Al2O3 were not active under the same reaction conditions. We found that the glycerolysis of triacylglyceride occurred in series with the reverse of the transesterification of the triacylglyceride when the catalyst amount was 6 wt% of the lipids and the ethanol:lipid molar ratio was 24 and 48 and the reaction time was 60 min. (C) 2019 Elsevier Ltd. All rights reserved.

PubMed: 31622724, POSS, regarded as the smallest silica particle, is widely used as nanofiller in polymer systems. POSS-based nanocomposites are deduced as novel materials having potency for biomedical applications owing to the enhanced biocompatibility and physicochemical characteristics. The aim of this work was to integrate the beneficial features of chitosan (CS) and OctaTMA-POSS nanoparticle to design nanocomposite for bone tissue regeneration. The nanocomposite scaffolds were fabricated by freeze-drying. The effects of POSS incorporation on morphology and structure of CS matrix were examined. Bioactivity and osteogenic effects of the POSS nanoparticles were investigated with cytocompatibility, cell proliferation, alkaline phosphatase activity, osteocalcin production and biomineralization assays. PUSS incorporation altered the surface morphology by increasing surface roughness. Nanocomposite scaffolds with 82-90% porosity exhibited an increase in compression modulus of scaffolds (78-107 kPa) compared to control CS group (56 kPa). Results indicated that CS-POSS scaffolds were found cytocompatible with 3T3, MG-63 and Saos-2 cell lines. POSS incorporation showed promising effects on osteoblast adhesion and proliferation as well as increasing ALP activity, octeocalcin secretion and biomineralization of cells. (C) 2019 Elsevier B.V. All rights reserved.

Brushite forming calcium phosphate cements (CPCs) have received growing interest for scaffold applications due to their high surface area and high bioresorbability. The dehydrated form of brushite, monetite, has a finer microstructure with higher surface area, higher strength and bioresorbability comparable to brushite, making it a viable alternative phase in CPCs. The increase in monetite content of the β-tricalcium phosphate (β-TCP)–monocalcium phosphate monohydrate (MCPM) cement system due to the reduction in its supersaturation upon addition of NaCl to excess setting liquid was investigated kinetically. The relaxation period was monitored by pH-stat titration of the cement solution by 0.1 M NaOH. Monetite growth was achieved in shorter periods at higher NaCl concentrations where the supersaturation gap between brushite and monetite is thought to be narrowed due to high ionic strength in accord with Pitzer's ion interaction model. The brushite/monetite ratio decreased consistently with increasing NaCl concentration in the 3–6 M range.

Phase behaviors of 1,2-Distearoyl-sn-glycero-3-phosphocholine (DSPC) and polyoxyethylene(40)stearate (PEG40St) were investigated with Langmuir monolayer isotherms and Brewster angle microscopy (BAM) imaging at DSPC/PEG40St molar ratios ranging from 9:1 to 5:5. Two plateaus were found in the Langmuir isotherms which were relatively shorter for the 9:1 mixture and extended significantly by increasing the PEG40St content, indicating that the PEG40St squeezed out whereas more emulsifier retained in the monolayer at higher PEG40St contents. A strong hysteresis was observed when the mixed monolayers were subjected to compression-expansion cycles. The degree of hysteresis for the first cycles also increased with increasing PEG40St content in the monolayer. Gray scale intensities in the Brewster angle microscopy images were determined for pure DSPC and pure PEG40St and a scale was established to better interpret the morphologies for the mixtures. Bud and vessels formed during the PEG40St squeezed out upon compression. Upon expansion, PEG40St and DSPC is reappeared on the monolayer. When considered BAM images together with the Langmuir isotherm, PEG40St molecules were found to be well distributed within the DSPC molecules at lower DSPC/PEG40St mole ratios and mostly phase separated at higher mole ratios. It was concluded that higher PEG40St content would be advantageous for the design of an efficient and cheaper ultrasound contrast agents., TUBITAK (113M270)

Lubricants consist of base oils and chemical additives such as dispersants, surfactants, oxidation inhibitors, and antiwear agents. Organic and inorganic boron-based additives increase wear resistance and decreases friction. Hexagonal boron nitride and metal borates are used for this purpose. Zinc borate is a synthetic hydrated metal borate. The production techniques of zinc borate generally include the reaction between zinc source materials (zinc oxide, zinc salts, zinc hydroxide) and the boron source materials (boric acid and borax). The nano zinc borate particles were prepared from zinc nitrate and borax in the present study by using low initial zinc and borate concentrations and low temperature to prevent particle growth. The templates span 60 and PEG 4000 were used to control the particle size. The particles were separated from mother liquor by centrifugation, washed with ethanol, dried and ground and used as additive to base oil. The particles have H2O and B(3)-O vibrations in their FTIR spectra. The empirical formula of the nanoparticles was approximately 3ZnO.2B2O3.4H2O from EDX and TGA analysis. X-ray diffraction diagram indicated the particles were in amorphous state. When the nanoparticles were added to light neutral oil the wear scar diameter and friction coefficient was lowered 50% and 20% respectively.

In this study, natural silica source, diatomite, incorporated novel chitosan based composite membranes were fabricated and characterized for bone tissue engineering applications as possible bone regeneration membrane. The effect of diatomite loading on the mechanical, morphological, chemical, thermal and surface properties, wettability and in vitro cytotoxicity and cell proliferation on of composite membranes were investigated and observed by tensile test, atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA), protein adsorption assay, air/water contact angle analysis and WST-1 respectively. Swelling studies were also performed by water absorption capacity determination. Results showed that incorporation of diatomite to the chitosan matrix increased the surface roughness, swelling capacity and tensile modulus of membranes. An increase of about 52% in Young's modulus was achieved for 10 wt% diatomite composite membranes compared with chitosan membranes. High cell viability results were obtained with indirect extraction method. Besides, in vitro cell proliferation and ALP activity results showed that diatom incorporation significantly increased the ALP activity of Saos-2 cells cultured on chitosan membranes. The novel composite membranes prepared in the present study with tunable properties can be considered as a potential candidate as a scaffold in view of its enhanced physical & chemical properties as well as biological activities for bone tissue engineering applications., Scientific Research Project of Izmir Institute of Technology (2011 IYTE02)

Boron industrial solid waste is used as reinforcement for preparing composite materials. This waste has boron trioxide which holds unique properties may affect the surface or interface of the composite. The prepared composites are characterized in order to determine the dispersion and the structure by means of inverse gas chromatography (IGC), Fourier transform infrared spectroscopy, thermal gravimetric analysis, scanning electron microscopy (SEM) and X-ray diffraction (XRD). There is a strong relation between the dispersion of reinforcement and the properties of newly formed composite. The dispersive component of the surface energies of the composites and components are determined by IGC. This parameter is difficult to measure by other methods and it is related to the wettability and adhesive characters of solid materials. The effect of compounding ratios of reinforcement is also examined. Furthermore, XRD diffractograms and SEM images of composites showed well dispersion. Thermal analysis revealed that the addition of the boron industrial solid waste to the polymer increased the thermal stability of pure polymer. Infrared spectra of the composites indicated that the composites were formed from the waste reinforcement and the polymer matrix., The Scientific Research Fund of Eskişehir Osmangazi University [grant number 201015040]

Polymer nanocomposites, based on bacterial biodegradable thermoplastic polyester, poly(hydroxy-butyrate) (PHB), poly(hydroxyl-butyrate-co-hydroxy-valerate) (PHBHV), and commercial organo-modified montmorillonite (OMMT-Cloisite 10A) were prepared by solution casting method. This work aims to investigate the effect of Cloisite 10A type clay addition on the water vapour permeability properties of PHB/OMMT, and PHBHV/OMMT nanobiocomposite films. Temperature dependence of water vapor permeabilities of the films were also evaluated at various temperatures, and semi empirical permeability models were used to predict the permeability of polymer systems as a function of clay concentration and aspect ratio of nanoplates. Moreover, thermal, optical, and mechanical properties of the composites were examined by using varieties of techniques including differential scanning calorimeter (DSC), thermogravimetric analyzer (TGA), scanning electron microscope (SEM), and thin-film X-ray diffractometer (TF-XRD) respectively. Test results indicated that addition of highly intergallery swollen Cloisite 10A to the PHB/PHBHV, reduced the water vapor permeability up to 41 and 25% compared to native PHB and PHBHV films, respectively. Regarding the all mechanical properties measured, the maximum improvement was achieved for 3 wt% clay loaded samples for both PHB and PHBHV polymer composites. An increase of about 152 and 73% in tensile strength and of 77 and 18% in strain at break was achieved for PHB and PHBHV polymers, respectively. As a result of X-ray diffraction analysis, exfoliated structure was achieved at low clay loaded sample (1% w/w), however at higher concentration (3% w/w) the structure found as intercalated. Therefore, it is an evident that enhancement of characteristic properties highly depend on the dispersion level of clay particles in polymer matrix. The results obtained in this study show the feasibility of improvement of the properties of PHB based polymers with incorporation of nanoclay., National Research Council of Turkey (TUBITAK 108M335)

The development of a better understanding of the low temperature nanophase evolution of high surface area titania (TiO2) based powders is essential for their use in photocatalytic applications. A series of rare earth (RE) element doped TiO2 powders were prepared by sol-gel processing. The effects of RE doping level, ionic size and heat treatment temperature on the nanophase structure evolution and the dopant ion location in TiO2 main matrix were investigated. Anatase was determined to be the main phase up to 900 °C at all doping levels for all REs. Anatase to rutile phase transformation was inhibited by RE doping. The inhibitory effect of REs increased with increasing ionic radius. Oxide phases of La, Nd, Pr, Sm were not present up to 5% and Nd4Ti9O24 phase was formed at 10% doping level at 800 °C. The formation of RE2Ti2O7 phases were determined for the REs with relatively lower ionic radii at 800 °C., Scientific and Technological Research Council of Turkey (TUBITAK 10M739)

Clinoptilolite supported rutile TiO2 composites were synthesized for the enhancement of its photocatalytic performance in the degradation of the aqueous terephthalic acid solution under UVC illumination by the increase in its surface area and to simplify its recovery from the treated solution after use. The XRD spectra of the composites revealed the formation of pure rutile TiO2 on the surface of the clinoptilolite. The SEM images showed the formation of the spherical TiO2 clusters were composed of nano fibers on the surface of the clinoptilolite. For all composites synthesized, the dispersion of the TiO2 particles on the clinoptilolite led to a surface area larger than that of the bare TiO2 and clinoptilolite. The materials synthesized in the present study exhibited higher catalytic activity compared with the commercial Degussa P25 and anatase. Among the catalysts synthesized the TiO2/clinoptilolite with a weight ratio of 0.5 was found to be the most photoactive catalyst even though it contains a lesser amount of active TiO2. The kinetic of the reactions for different catalyst was found to be consistent with the pseudo-first order kinetic model. The results of the Langmuir-Hinshelwood model showed the slight contribution of the adsorption on the degradation. The activity of the TiO2/clinoptilolite with a weight ratio of 0.5 decreased after repetitive use due to the accumulation of the TPA molecules on the surface of the catalyst., Scientific and Technological Research Council of Turkey (TUBITAK 104M255-110M451); Science, Technology Application, and Research Center of Ege University (EBILTEM) (2012/BIL/027); Scientific Research Council of Ege University (13MUH031)

WOS: 000395353600090, PubMed ID: 27939936, Atmospheric and concurrent soil samples were collected during winter and summer of 2014 at 41 sites in Kutahya, Turkey to investigate spatial and seasonal variations, sources, air-soil exchange, and associated carcinogenic risks of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs). The highest atmospheric and soil concentrations were observed near power plants and residential areas, and the wintertime concentrations were generally higher than ones measured in summer. Spatial distribution of measured ambient concentrations and results of the factor analysis showed that the major contributing PAH sources in Kutahya region were the coal combustion for power generation and residential heating (48.9%), and diesel and gasoline exhaust emissions (473%) while the major PCB sources were the coal (thermal power plants and residential heating) and wood combustion (residential heating) (45.4%), and evaporative emissions from previously used technical PCB mixtures (34.7%). Results of fugacity fraction calculations indicated that the soil and atmosphere were not in equilibrium for most of the PAHs (88.0% in winter, 87.4% in summer) and PCBs (76.8% in winter, 83.8% in summer). For PAHs, deposition to the soil was the dominant mechanism in winter while in summer volatilization was equally important. For PCBs, volatilization dominated in summer while deposition was higher in winter. Cancer risks associated with inhalation and accidental soil ingestion of soil were also estimated. Generally, the estimated carcinogenic risks were below the acceptable risk level of 10-6. The percentage of the population exceeding the acceptable risk level ranged from 10-6, Scientific and Technological Research Council of Turkey [TUB/112Y305]; Anadolu University research fund for scientific projects [1306F272]; Gizem Tuna Tuygun and Hasan Altiok (Dokuz Eylul University), This study was supported by The Scientific and Technological Research Council of Turkey (project no: TUB/112Y305) and by Anadolu University research fund for scientific projects (project no: 1306F272). We would like to thank Gizem Tuna Tuygun and Hasan Altiok (Dokuz Eylul University) for their support during the study.

Polyurethane foam (PUF) passive samplers were employed to assess air concentrations of polychlorinated biphenyls (PCBs) in background, agricultural, semi-urban, urban and industrial sites in Bursa, Turkey. Samplers were deployed for approximately 2-month periods from February to December 2014 in five sampling campaign. Results showed a clear rural-agricultural-semi-urban-urban-industrial PCBs concentration gradient. Considering all sampling periods, ambient air concentrations of Σ43PCBs ranged from 9.6 to 1240 pg/m3at all sites with an average of 24.1 ± 8.2, 43.8 ± 24.4, 140 ± 190, 42.8 ± 24.6, 160 ± 280, 84.1 ± 105, 170 ± 150 and 280 ± 540 pg/m3for Mount Uludag, Uludag University Campus, Camlica, Bursa Technical University Osmangazi Campus, Hamitler, Agakoy, Kestel Organised Industrial District and Demirtas Organised Industrial District sampling sites, respectively. The ambient air PCB concentrations increased along a gradient from background to industrial areas by a factor of 1.7–11.4. 4-Cl PCBs (31.50–81.60%) was the most dominant homologue group at all sampling sites followed by 3-Cl, 7-Cl, 6-Cl and 5-Cl homologue groups. Sampling locations and potential sources grouped in principal component analysis. Results of PCA plots highlighted a large variability of the PCB mixture in air, hence possible related sources, in Bursa area. Calculated inhalation risk levels in this study indicated no serious adverse health effects. This study is one of few efforts to characterize PCB composition in ambient air seasonally and spatially for urban and industrial areas of Turkey by using passive samplers as an alternative sampling method for concurrent monitoring at multiple sites., Scientific and Technological Research Council of Turkey (21514107-221.01-8290); TUBITAK (112Y315)

Purpose This paper aims to present a novel and cost-effective optical biosensor design by simple preparation method for detection of “parathion-methyl,” which is a model pesticide pose to public health and the environment. Design/methodology/approach The optical enzyme biosensor (TCA) for detection of pesticide “parathion-methyl” was developed on the basis of immobilization of tyrosinase enzyme on chitosan film by adsorption technique. The analytic performance of TCA was investigated by measuring its activity with Ultraviolet (UV) visible spectrophotometer. Findings Uniform porous network structure and protonated groups of chitosan film provided a microenvironment for tyrosinase immobilization evident from Fourier transform infrared (FTIR) spectroscopy and Atomic Force Microscopy analysis. TCA has a wide linear detection range (0-1.03 µM) with high correlation coefficient and it can detect the parathion-methyl concentration as low as 159 nM by noncompetitive inhibition kinetics. Using the TCA sensor both for ten times and at least 45 days without a significant loss in its activity are the indicators of its good operational and storage stability. Moreover, TCA can be applicable to tap water, providing a promising tool for pesticides detection. Originality/value This is the first time to use the in situ analytical technique that can improve the performance of optical enzyme sensor provided to control the pesticide residue better with respect to traditional techniques. The effect of organic solvents on the performance of optical enzyme biosensor was investigated. Inhibition kinetic of the solvents rarely encountered in literature was also studied besides the pH and temperature tolerance of the optical biosensor.

Polycyclic aromatic hydrocarbons (PAHs) and some of their nitrated derivatives, NPAHs, are seemingly ubiquitous in the atmospheric environment. Atmospheric lifetimes may nevertheless vary within a wide range, and be as short as a few hours. The sources and sinks of NPAH in the atmosphere are not well understood. With a Lagrangian field experiment and modeling, we studied the conversion of the semivolatile PAHs fluoranthene and pyrene into the 2-nitro derivatives 2-nitrofluoranthene and 2-nitropyrene in a cloud-free marine atmosphere on the time scale of hours to 1 day between a coastal and an island site. Chemistry and transport during several episodes was simulated by a Lagrangian box model i.e., a box model coupled to a Lagrangian particle dispersion model, FLEXPART-WRF. It is found that the chemical kinetic data do capture photochemical degradation of the 4-ring PAHs under ambient conditions on the time scale of hours to 1 day, while the production of the corresponding NPAH, which sustained 2-nitrofluoranthene/fluoranthene and 2-nitropyrene/pyrene yields of (3.7 ± 0.2) and (1.5 ± 0.1)%, respectively, is by far underestimated. Predicted levels of NPAH come close to observed ones, when kinetic data describing the reactivity of the OH-adduct were explored by means of theoretically based estimates. Predictions are also underestimated by 1-2 orders of magnitude, when NPAH/PAH yields reported from laboratory experiments conducted under high NOx conditions are adopted for the simulations. It is concluded that NPAH sources effective under low NOx conditions, are largely underestimated., Grant Agency of the Czech Republic (P503 16-115375); Izmir Institute of Technology Research Fund (2013IYTE-14); Max Planck Society; European Union (262254); Ministry of Education, Youth & Sports - Czech Republic (LM2015051/CZ.02.1.01/0.0/0.0/16_013/0001761)

WOS: 000456637900023, PubMed: 30445350, The aim of this study is to prepare high flux, stable, antifouling nanofiltration membranes through single bilayer polyelectrolyte deposition. To this end, a tight ultrafiltration support membrane was prepared from a polysulfone/sulfonated polyethersulfone blend. Deposition of a polyethyleneimine and alginate pair on this support has reduced the molecular weight cut off from 6 kDa to below 1 kDa. The pure water permeability and polyethylene glycol 1000 rejection of the coated membrane were found to be 15.5 +/- 0.3 L/m(2).h.bar and 90 +/- 0.6%, respectively, by setting the deposition pH for each layer to 8 and the ionic strengths to 0.5 M and 0 M. This membrane has exhibited significantly higher permeability than commercial membranes with the same molecular weight cut off, retaining 98% of the initial flux during 15 h filtration of bovine serum albumine. In addition, the membrane has been able to completely remove anionic dyes from aqueous solution by showing 99.9% retentions to Reactive red 141, Brilliant blue G and Congo red with a 2 bar transmembrane pressure. High flux and membrane stability in acidic and salty environments have been achieved when deposition conditions favor high adsorption levels for the first layer and strong ionic cross-linking between the carboxyl group on the alginate and the amine groups on the polyethyleneimine. (C) 2018 Elsevier Inc. All rights reserved.

Despite the advancements in bone transplantation operations, inflammation is still a serious problem that threatens human health at the post-implantation period. Conventional antibiotic therapy methods may lead to some side effects such as ototoxicity and nephrotoxicity, especially when applied in high doses. Therefore, local drug delivery systems play a vital role in bone disorders due to the elimination of the disadvantages introduced by conventional methods. In the presented study, it was aimed to develop Vancomycin (VC) and Gentamicin (GC) loaded chitosan-montmorillonite nanoclay composites (CS/MMT) to provide required antibiotic doses to combat post-implantation infection. CS/MMT nanocomposite formation was supplied by microfluidizer homogenization and spherical drug carrier nanoparticles were obtained by electrospraying technique. Three factors; voltage, distance and flowrate were varied to fabricate spherical nanoparticles with uniform size. Emprical model was developed to predict nanosphere size by altering process variables. Nanospheres were characterized in terms of morphology, hydrodynamic size, zeta potential, drug encapsulation efficiency and release profile. Drug loaded nanospheres have been successfully produced with a size range of 180-350 nm. Nanocomposite drug carriers showed high encapsulation efficiency (80%-95%) and prolonged release period when compared to bare chitosan nanospheres. The drug release from nanocomposite carriers was monitored by diffusion mechanism up to 30 d. The in vitro release medium of nanospheres showed strong antimicrobial activity against gram-positive S. aureus and gram-negative E. coli bacteria. Furthermore, it was found that the nanospheres did not show any cytotoxic effect to fibroblast (NIH/3T3) and osteoblast (SaOS-2) cell lines. The results demonstrated that the prepared composite nanospheres can be a promising option for bone infection prevention at the post implantation period., TUBITAK (116M096)

In this paper, a novel hybrid process for the treatment of microcrystalline cellulose (MCC) under hot-compressed water was investigated by applying constant direct current on the reaction medium. Constant current range from 1A to 2A was applied through a cylindrical anode made of titanium to the reactor wall. Reactions were conducted using a specially designed batch reactor (450 mL) made of SUS 316 stainless steel for 30–120 min of reaction time at temperature range of 170–230 °C. As a proton donor H2SO4 was used at concentrations of 1–50 mM. Main hydrolysis products of MCC degradation in HCW were detected as glucose, fructose, levulinic acid, 5-HMF, and furfural. For the quantification of these products, High Performance Liquid Chromatography (HPLC) and Gas Chromatography with Mass Spectroscopy (GC–MS) were used. A ½ fractional factorial design with 2-level of four factors; reaction time, temperature, H2SO4 concentration and applied current with 3 center points were built and responses were statistically analyzed. Response surface methodology was used for process optimization and it was found that introduction of 1A current at 200 °C to the reaction medium increased Total Organic Carbon (TOC) and cellulose conversions to 62 and 81 %, respectively. Moreover, application of current diminished the necessary reaction temperature and time to obtain high TOC and cellulose conversion values and hence decreased the energy required for cellulose hydrolysis to value added chemicals. Applied current had diverse effect on levulinic acid concentration (29.9 %) in the liquid product (230 °C, 120 min., 2 A, 50 mM H2SO4). © 2016, Springer Science+Business Media Dordrecht., Marie Curie Career Integration Grants (FP7-PEOPLE-CIG) PCIG11-GA-2012-321741

The effect of acidic or basic pre-treatment on the adsorption capacity of CO2 on coals was investigated. Argonne Premium Pocahontas No. 3, Upper Freeport, Pittsburgh No. 8, Lewiston–Stockton, Blind Canyon, Illinois No. 6, Wyodak, and Beulah–Zap coals were washed in weak solutions of H2SO4 and NaOH to the pH values of 10, 7, and 2, after an initial washing in acidic water. Attempts to treat the Wyodak and Beulah–Zap coals were unsuccessful because the base treatment after the initial acid treatment resulted in a suspension which could be separated neither via filtration through a 45 μm filter nor centrifugation. Equilibration took several days in some cases, although the as-received coal had been ground to 150 μm. Acid washing preferentially removed Ca (calcite) and Mg. Aluminosilicate clays were not notably removed. Iron was removed in significant amounts only after base treatment, possibly after it was converted to hematite. The adsorption capacity of CO2 on the acid treated coals was higher than both the base treated and untreated coals. The difference in adsorption capacities for acid and base treated coals was related to the pore sizes and mineral matter removal from the coals, where the calculated average pore size was higher for acid treated coals than for the base treated coals. It is concluded that the pH decrease due to CO2 dissolution in cleat water is favored in coal seam sequestration, which resulted in an increase in storage capacity of coals.

The effect of calcium hydroxide (Ca(OH)2) on the stability of calcium carbonate (CaCO3) particles was investigated with respect to the surface potential and particle size. Both CaCO3 and Ca(OH)2 were dissolved in ultrapure water at concentrations up to 100 mM. The solubility limits were about 18 mM for Ca(OH)2 and about 0.13 mM for CaCO3 at 23 °C in water. Dissolution of commercial CaCO3 in 10 mM of Ca(OH)2 solution and dissolution of Ca(OH)2 in 10 mM of CaCO3 slurry were also studied at similar conditions. Conductivity, pH, zeta potential, and average particle sizes were measured for each solution. The morphological characteristics of the particles were analyzed by the SEM images. It was found that the zeta potential of CaCO3 particles was greater than + 30 mV when they were placed in the Ca(OH)2 solution compared to a zeta potential value of - 10 mV in water. It was concluded that the Ca(OH)2 solution is a stabilizer for the CaCO3 particles., Scientific and Technological Research Council of Turkey (TUBITAK MAG 110M104)

The main purpose of this study is to model one-dimensional, premixed, laminar, burner-stabilized, fuel-rich n-heptane flame to understand its combustion characteristics. Detailed chemical kinetic modeling technique was used to obtain more information about the formation nature of emissions in n-heptane flame. A detailed chemical kinetic mechanism was generated by combining several mechanisms from the literature that related with possible products of fuel-rich n-heptane combustion. The mechanism consists of 4185 reactions and 893 species. Validations of the mechanism were done by species mole fractions of premixed laminar flames and jet stirred reactors, and ignition delay times in shock tubes. A detailed investigation of the n-heptane flame was carried out using rate of production and reaction pathway analyses. Propargyl radical (C3H3), vinylacetylene (C4H4) and acetylene (C2H2) were found as the main precursors of benzene formation. The mechanism was able to predict most of the major, minor, and trace species up to four-fused aromatic rings formed in the flame. A skeletal mechanism was also generated using Directed Relation Graph with Error Propagation (DRGEP) method. It consists of 1879 reactions and 359 species. The skeletal mechanism was in a good agreement with the detailed mechanism on the species mole fraction predictions.

WOS: 000445987500038, Polyamide-imides (PAI) are attractive materials for membrane formation due to their high chemical and thermal stability. In this study, we report a facile approach for preparing positively charged nanofiltration (NF) membranes using a one-step process. Polyethylenimine (PEI) was dissolved in a coagulation bath and formed in-situ ionic crosslinking with PAI during phase inversion. The membranes were characterized by attenuated total reflectance Fourier Transform Infrared spectroscopy (ATR-FTIR), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), atomic force microscopy (AFM), contact angle and zeta potential measurements. The most positively charged membrane was obtained when the pH of the coagulation bath was adjusted to 10. This membrane showed a significant decrease in contact angle and surface roughness and increase in the pure water permeability (PWP) compared to the plain PAI membrane. The salt rejection performance of the cross linked PAI membrane was measured using MgCl2, CaCl2, NaCl and Na2SO4 salts. The rejection of Mg2+ and Ca2+ ions was found to be 95.6% and 90.2%, respectively. The crosslinked membrane showed excellent chemical stability when stored in HCl solution at pH 3 up to 7 days. Antifouling behaviour of the optimized membrane was tested using bovine serum albumin (BSA) and flux recovery ratio of the membrane was found to be 92.2% at the end of 3 h filtration. The results suggest that the positively charged PAI membranes crosslinked with PEI may have a potential in recovering valuable cationic metals from acid mine wastewater.

WOS: 000441177500052, In this study, glycidyl methacrylate and 1H, 1H, 2H, 2H-perfluorodecyl acrylate copolymer p(GMA-co-PFDA) thin-films fabricated via Initiated Chemical Vapor Deposition (iCVD) were investigated as protective coatings on optical BK7 glass substrates and commercial optical filters. Durability tests based on military standards MIL-F-48616 and MIL-C-48497A were performed to evaluate performance of coatings for the protection of surfaces of optical elements. Cross-linked p(GMA-co-PFDA) copolymer coatings successfully passed all durability tests showing excellent mechanical properties and protection against humidity, salt water, swelling in water, and resistance to organic solvents while providing excellent adhesion to substrate. iCVD process enabled fine tuning of film morphology, mechanical properties and hydrophobicity by controlling the process parameters. Fabricated films were hydrophobic and highly transparent (> 98%) in the wavelength range from 300 nm to 1000 nm. Optical transmittance measurements before and after coating process proved that while providing chemical and physical protection, p(GMA-co-PFDA) copolymer thin-films do not cause any detectable change in optical performance of commercial narrow band and wide band filters.

Bulmus, Volga/0000-0001-9944-1444, WOS: 000434745200044, Synthetic peptides with cyclic arginine-glycine-aspartate motif (cRGD) play an important role in cell recognition and cell adhesion. cRGD-decorated soluble polymers and polymeric nanoparticles have been increasingly used for cell-specific delivery of antitumor drugs. While the significance of cRGD modification for tumor cell-specific targeting of polymeric carriers is well-accepted, straightforward procedures ensuring the fidelity of cRGD modification of polymeric systems are still lacking. Herein, we have reported an in-situ polymerization approach for synthesis of cRGD-end-functionalized well-defined polymers as potential building blocks of targeted drug delivery systems. A new cRGD peptide functionalized RAFT agent was synthesized as confirmed by MALDI-TOF and H-1 NMR spectroscopy. The ability of this RAFT agent to control polymerizations was then tested using two different monomers oligoethyleneglycol acrylate and t-butyl methacrylate. The RAFT-controlled character of polymerizations and the living characteristic of the synthesized polymers were investigated through a series of kinetic experiments. The cytotoxicity and targeting capability of cRGD-functionalized OEGA polymers were investigated using cell lines expressing alpha(v)beta(3) integrins at varying extents.

Tihminlioglu, Funda/0000-0002-3715-8253, WOS: 000442192000028, PubMed: 30033256, As a natural and abundant silica mineral, diatomite particles (SiO2-nH(2)O) have been used in several areas such as filtration, photonics, sound and heat insulation, filler material and drug delivery due to its abundance, inexpensive cost, unique morphology and porous structure. But up to date, diatomite incorporated silica based scaffolds have not been used for bone tissue engineering applications. In the present study, the goal was to combine the useful biomaterial properties of both chitosan and diatomite as biocomposite organic/inorganic biomaterial for bone tissue engineering applications and optimize the silica content of the composites in order to obtain optimum morphological structure, high mechanical properties, enlarged surface area and enhanced cell proliferation. The effect of silica loading on the mechanical, morphological, chemical, and surface properties, wettability and biocompatibility of composite scaffolds were investigated. In addition, in vitro cytotoxicity and cellular activities including cell proliferation, ALP activity and biomineralization were investigated in order to determine biological activity of the composite scaffolds. Diatomite particles lead to enhancement in the water uptake capacity of scaffolds. Chitosan-silica composites exhibited 82-90% porosity. Wet chitosan-silica composite scaffolds exhibited higher compression moduli when compared to pure chitosan scaffold in the range of 67.3-90.1 kPa. Average pore size range of chitosan-diatomite composite scaffolds was obtained as 218-319 mu m. In vitro results indicated that chitosan-diatomite composites did not show any cytotoxic effect on 3T3, MG-63 and Saos-2 cell lines. Scaffolds were found to be favorable for osteoblast proliferation. Diatomite incorporation showed promising effects on enhancing ALP activity as well as mineral formation on scaffold surface. Thus, the prepared scaffolds in this study can be considered prospective material for bone tissue engineering applications.

In this study, the layer-by-layer (LbL) assembly method was employed to modify a commercial polyethersulfone (PES) membrane by successive adsorption of chitosan and alginate as cationic and anionic polyelectrolytes. To enhance anti-biofouling property, pure, PEG mixed and PEGylated AgCl/TiO2 xerogels were incorporated solely in the top layer of the LbL-modified membranes. Organic and biological foulings were addressed separately using alginate and Escherichia coli bacteria suspensions as the organic and biological model foulants, respectively. LbL-modifying the commercial PES membrane successively with chitosan and alginate polyelectrolyte multilayers prevented organic fouling extensively. In addition, we found that AgCl/TiO2-incorporated membranes show higher water permeability and improved resistance to biological fouling as compared to the PES membrane. Silver amounts in consecutively collected permeate samples were quantified by ICP-MS analysis to assess the stability of AgCl/TiO2-incorporated layers. Silver loss per filtration cycle followed an increasing trend initially, up to a filtration volume totaling 3000L/m2, leading to 4.2% reduction in the immobilized silver amount. After that, silver loss per filtration cycle stabilized at ~7.44μg/L, which extrapolates to ~265 days time-span for the remaining silver to be released at a filtration rate of ~1000L/m2 h. Antibacterial activity tests showed that AgCl/TiO2-incorporated layers do not permit bacterial growth on the membrane surface., European Union (246039)

Aqueous precipitation products of Zn(NO3)2 and NaOH obtained by changing the method of combining the reactants and by using lysozyme as an additive were investigated. In the case of single addition method, octahedral e-Zn(OH)2 and plate-like β-Zn(OH)2 structures formed in the absence and in the presence of lysozyme, respectively. Calcination of these Zn(OH)2 samples at 700 °C yielded porous ZnO structures by conserving the template crystals. When zinc source was added dropwise into NaOH solution, predominantly clover-like ZnO crystals were obtained independent of lysozyme addition. Mixed spherical and elongated ZnO morphology was observed when NaOH was added dropwise into Zn(NO3)2 solution containing lysozyme. Lysozyme contents of the precipitation products were estimated as in the range of ∼5–20% and FTIR indicated no significant conformational change of lysozyme in the composite. These results suggest that lysozyme-ZnO/Zn(OH)2 composite materials may have a value as an antibacterial material.

Water repellency on natural stone surfaces is the most important issue in the protection of stone monuments from effects of atmospheric pollutants. In this study, effectiveness of a bio-nano composite coating, composed of a biodegradable polymer (poly-L-lactide [PLA]) and montmorillonite clay (MMT) was investigated for the protection of marble surfaces from pollution. The clay dispersion in polymer matrices was analyzed by using Scanning Tunnel Electron Microscopy (STEM) and X-Ray Diffraction (XRD), while protection performance was investigated by the measurement of surface roughness, wettability, water vapor permeability, capillary water absorption, and color changes on the marble surfaces. As a result, no alteration on the color of coated marbles was observed, significant improvement was obtained for hydrophobicity of the surface and inhibition of sulfation reaction on the exposed marble surfaces under acidic atmosphere. It could be said that PLA based nanocomposites seem to be promising materials as protective coating agents in reducing the effects of water and atmospheric pollutants on marble surfaces., Scientific and Technical Research Council of Turkey (108M335)

The objective of this study is to improve the blood compatibility of polysulfone (PSF) based hemodialysis membranes through generating antioxidative surfaces with superoxide dismutase (SOD)/catalase (CAT) enzyme couple immobilization. Enzymes were attached both covalently and ionically on the plasma treated and polyethyleneimine (PEI) deposited membranes, respectively. The loss of enzymes from PEI modified surface at the end of 4 h was found to be relatively higher during storage in phosphate buffered saline (PBS) at pH 7.4 when compared to the enzymes on the plasma treated surface. The kinetic studies indicated that SOD catalyzed the reaction in the diffusion-limited regime at all substrate concentrations and its inactivation by hydrogen peroxide was prevented in the presence of CAT. SOD/CAT coated PSF membranes were capable of reducing the levels of reactive oxygen species in blood and can significantly prolong activated partial thromboplastin time. In addition, both the adsorption of human plasma proteins and platelet activation on all modified membranes decreased significantly compared to the unmodified PSF membranes. Proposed modification methods did not affect high permeability, high mechanical strength or the non-toxic properties of the PSF membranes., L'Oreal Turkey Women in Science Program; Izmir Institute of Technology (2010IYTE03)

Monodisperse silica spheres in the 50–520 nm size range were prepared by using the Stober process. Diffusive growth has been determined from Nielsen chronomal analysis for the 520 and 310 nm monodisperse silica spheres. The densification behaviour and evolution of the microstructure of the sphere compacts indicated an inverse dependence of shrinkage rate on the sphere size due to viscous sintering. The increase in sphere size from 50 to 500 nm shifted the densification temperature from ~1120 °C to 1240 °C. The amorphous nature of the spheres was conserved up to 1200 °C where cristobalite crystal nucleation started and complete transformation to cristobalite phase has been observed upon heat treatment at 1300 °C. The activation energies for viscous sintering according to the Frenkel and Mackenzie/Shuttleworth models were calculated as 125 and 335 kJ/mol, respectively. These substantially low activation energies can be attributed to the presence of a significant level of silanol groups.

Recent studies in wound dressing applications offer new therapies and promote wound healing process. The aim of this study was to develop Hypericum perforatum (St John's Wort) oil incorporated chitosan films for wound dressing applications. H. perforatum oil as a potential therapeutic agent was encapsulated in chitosan film to achieve a better wound dressing material. Oil incorporated chitosan films were successfully prepared by solvent casting method in different oil concentrations (0.25-1.5%v/v). Water vapor permeability (WVP), mechanical test, swelling behavior and surface hydrophobicity were performed in order to characterize the prepared films. Antimicrobial test was performed by disc diffusion method and the growth inhibition effects of the films including different amount of H. perforatum oil were investigated on Escherichia coli and Staphylococcus aureus. WVP increased with oil incorporation and the highest value was obtained for 0.25% oil concentration.The highest strain value was obtained in 0.25% oil content films although tensile stress decreased with increasing oil content. H. perforatum oil incorporated films had antimicrobial effect on both microorganisms. Chitosan based films had no cytotoxic effects on NIH3T3fibroblast cells and provided a good surface for cell attachment and proliferation. The results showed that the H. perforatum incorporated chitosan films seems to be a potential and novel biomaterial for wound healing applications.

The surface properties of newly synthesized N-methoxy isopropyl acrylamide, N-methoxy isopropyl methacrylamide, cyclo propyl acrylamide, and cyclo propyl methacrylamide polymers were investigated using inverse gas chromatography. The highest dispersive component of the surface energy value was obtained for cyclo propyl methacrylamide at 30°C. The values obtained for all polymers were decreasing with the increasing temperature. The values obtained for the acidic and the basic parameters revealed strong basic characters for the surface of N-methoxy isopropyl methacrylamide and cyclo propyl methacrylamide polymers and weak basic characters for the surface of N-methoxy isopropyl acrylamide and cyclo propyl acrylamide polymers.

In this study, the effect of introduction of titania (TiO2) material into Pt-Ru/C anode electrocatalyst on the performance of direct methanol fuel cells (DMFCs) was investigated. TiO2 materials were first synthesized applying a sol-gel method and then incorporated directly into commercial Pt-Ru/C anode electrocatalyst with different TiO2 weight ratios (5, 15, and 25 wt.%) to improve the performance of the DMFC. For comparison, the anode electrocatalysts with the same TiO2 weight ratios were also prepared using commercial TiO2 materials. The performance tests of the DMFCs based on these composite anode electrocatalysts were conducted and their performances were also compared to that of a DMFC based on a traditional anode electrocatalyst (Pt-Ru/C) under various operating conditions. In addition, 4 h short-term stability tests were conducted for all the manufactured DMFCs. The highest power densities were found as 705.12 W/m(2) and 709.32 W/m(2) at 80 degrees C and 1 M for the DMFCs based on Pt-Ru/C-TiO2 anode electrocatalysts containing 5 wt.% of commercial and in-house TiO2, respectively. The results of the short-term stability tests showed that introduction of 5 wt.% of commercial TiO2 into commercial Pt-Ru/C anode electrocatalyst improved its stability characteristics significantly. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Kurt-Karakus, Perihan Binnur/0000-0001-6737-3475; Alegria, Henry/0000-0003-1685-2008, WOS: 000426356600056, PubMed: 29291570, Passive air samples were collected at eight sites in Bursa, Turkey during five sampling periods between February-December 2014. Locations encompassed urban, suburban, industrial, rural and background environments. Soil samples (n = 8) were collected at each site during February 2014. Six OPEs were detected in samples: tris(2-chloroethyl) phosphate (TCEP), tris(chloropropyl) phosphate (TCPP), triphenyl phosphate (TPHP), tris(2-butoxyethyl) phosphate (TBOEP), tris(2-ethylhexyl) phosphate (TEHP), and tris(2-isopropylphenyl) phosphate (T2-iPPP). Frequency of detection in air samples was TCPP and TPHP (100%) > TBOEP (88%) > TCEP (85%) > TEHP (78%) > T2iPPP (20%). Total OPEs in air per site by sampling period (excluding non-detects) ranged from 529 to 19,139 pg/m(3). In soil, total OPEs ranged from 38 to 468 ng/g dw. In air, alkylated OPEs dominated followed by halogenated and aryl OPEs. In air, annual mean concentrations were TBOEP > TCPP > TPHP > T2iPPP > TEHP > TCEP. In soils, alkylated OPEs were dominant at six sites and chlorinated OPEs at two sites. A comparison of OPE profiles between air and soil suggests that soils may be partly a source of OPEs to air. Mean concentrations in air were not directly proportional to temperature, and there were differences between alkylated compared to halogenated and aryl OPEs. In air, total and alkylated OPEs levels were fairly uniform, whereas more variability was found for the halogenated and aryl compounds. The relative contribution to total OPEs decreases for alkylated OPEs and increases for halogenated OPEs in samples going from background to suburban to urban and industrial sites. Levels of individual OPEs were all positively correlated between air and soils. In air, correlations between individual compounds were weak to moderate and were only statistically significant for TBOEP and TPHP. In soils, correlations were generally stronger and statistically significant only for TPHP and T2iPPP. (C) 2017 Elsevier B.V. All rights reserved.

Investigation of morphology of deoxyribonucleotide triphosphate (DNA) dried on different surfaces by atomic force microscopy (AFM) is important in DNA research that is focused on subjects of condensation for gene therapy, sizing, DNA mapping, and cancer examination. The solvent, the surface type, and the method of drying effect the morphology of DNA on solid surfaces. Ethanol and water were used as solvents, flat mica, silica, and alumina surfaces were used as the substrates in the present study. Different methods such as ambient air-drying, N2-forced flow regime drying, and freeze-drying have been applied to droplets of DNA solutions in water or ethanol on the substrates. Forced flow drying regime causes nonlinear DNA attachment on the surface and self-assembly. DNA vertical distance on mica surface was found to be 6 and 1.4 nm for DNA dried in ambient air from ethanol and water solutions, respectively. It was 1.6 nm for N2 flow drying of aqueous DNA solution on mica surface. It was 4.6, 4.6, and 1.99 nm for ambient, N2 flow, and freeze-dried aqueous DNA on alumina surfaces, respectively. Aqueous solution of DNA dried under N2 flow on silica surface had 0.8 nm vertical distance. The smallest standard deviation of 0.05 nm was observed for DNA dried under N2 flow on alumina surface.

A new methodology was introduced to produce hollow nano calcite particles in homogenous size distribution without aggregation. The design consisted of a jet flow system in which the crystallization region was separated from the stabilization region. The newly produced nano CaCO3 particles of about 140 nm were removed from the crystallization region as quickly as possible into the stabilization region before aggregation or crystal growth. In the stages of crystallization, the particles started to dissolve from their edges which opened-up the pores inside the particles. At the late stages of crystallization, the open pores closed. These particles were stable in Ca(OH)2 solution and no aggregation was detected. Different particles with different morphologies can be produced by adjusting the stages in the crystallization., Scientific and Technological Research Counsel of Turkey (TUBITAK 110M104)

Hydrothermal conversion of waste hazelnut shell in hot compressed water, green and environmentally friendly medium, was investigated under different operating conditions to clarify the effects of reaction temperature, reaction time, acid concentration and acid kind (H2SO4 and H3PO4) on the production of value-added chemicals with high temperature/high pressure autoclave. In literature, to our best knowledge, there is no study about the production of levulinic acid, as a high value chemical, from waste hazelnut shell in hot-compressed water without using any mineral and heterogeneous catalyst. Hydrothermal reactions were conducted at 150–280 °C for reaction times of 15 to 120 min with various H2SO4 and H3PO4 concentrations varying from 0 to 125 mM. The detailed liquid product species were identified with High Performance Liquid Chromatography (HPLC) and gaseous products were analyzed by Gas Chromatography with a Thermal Conductivity Detector (GC-TCD). The main identified liquid compounds were levulinic acid, acetic acid and furfural while carbon dioxide and carbon monoxide were the major gaseous products. Increasing the reaction temperature (280 °C) and reaction time (120 min) resulted in a significant increment on the conversion (65.40%) as well as levulinic acid yield (13.05%). The production of levulinic acid was enhanced with H2SO4 addition; whereas treatments with H3PO4 improved the furfural production., Marie Curie Career Integration Grants (FP7-PEOPLE-CIG) PCIG11-GA-2012-321741

Preparation and characterization of pure metal soaps and investigation of their effects on poly(vinyl chloride) (PVC) dehydrochlorination were the objectives of the present study. Magnesium stearate (MgSt2), cobalt stearate (CoSt2), and copper stearate (CuSt2) were prepared by a precipitation method. An aqueous sodium stearate (NaSt) solution was mixed at 500 rpm with respective metal salt solutions at 75oC. The precipitates that formed were collected by filtration, washed with water, and ultimately dried at 105oC under reduced pressure. Lamellar crystals that melted on heating were obtained. Solid-liquid phase transitions were observed by optical microscopy at 160oC, 159oC, and 117oC for MgSt2, CoSt2, and CuSt2, respectively. However, the melting points of MgSt2, CoSt2, and CuSt2 were determined as 115oC, 159oC, and 111oC, respectively, by analysis by differential scanning calorimetry. The onset temperature of the mass loss was the lowest at 255oC for CuSt2 and the lowest activation energy for thermal decomposition was 18 kJ/mol for CuSt2. CoSt2 was effective in extending the induction time of PVC dehydrochlorination at both 140oC and 160oC. The activation energy calculated from stability time decreased from 175 kJ/mol for a blank PVC sample to 114, 105, and 107 kJ/mol for MgSt2, CoSt2, and CuSt2-containing PVC samples, respectively. All three metal soaps accelerated the dehydrochlorination of PVC. J. VINYL ADDIT. TECHNOL., 21:235-244, 2015., TUBITAK (MISAG 185)

The isothermal crystallization and mechanical behavior of biodegradable polycaprolactone (PCL) composites with organic (oleic acid and glycerol monooleate) and inorganic (zinc oxide, organoclay, and hydroxy apatite) additives used alone or simultaneously were investigated. The effect of all additives on the degree of crystallinity percentage (DOC%), isothermal crystallization kinetics parameters, and mechanical test results of PCL composites was studied. The PCL composite films were prepared by solvent casting by using dichloromethane as the solvent. The films were characterized by X-ray diffraction, differential scanning calorimetry (DSC), and tensile tests. DSC of the first melting and X-ray diffraction DOC% results (for composites by solvent casting) are compatible. The values by DSC of the second melting (for composites by extrusion method) are lower. Organoclay gives the highest crystallinity among the other inorganic additives used. Small amounts of inorganic additives act as a nucleating agent and increase the crystallinity; the higher amounts decrease. The organic additives act as the plasticizer. When used alone, it lowers the crystallinity, but when used with inorganic additives, it improves the dispersion of inorganic particles in the polymer matrix. The isothermal crystallization kinetics parameters by Avrami analysis showed that crystallization was controlled by nucleation and the crystals had spherical structure. The nucleation type changed between thermal and athermal nucleation. The Pukanzky model interaction parameter B indicated that the organic additives improved the dispersion of inorganic particles in the polymer matrix. Statistically significant, eight correlations (F>6) were obtained for the crystallinity, crystallization parameters, Young's modulus, and tensile strength as a function of concentration of additives., Scientific and Technological Research Council of Turkey (110M157)

Methylene blue (MB) adsorption studies were performed with poly(vinyl chloride)-(dioctyl phthalate)-silica composites, which were obtained by using plastisol-plastigel technology. The films were flexible, having elastic modulus of 1.0–1.5 GPa. Diminishing MB concentration in the aqueous phase was followed as the adsorption process advanced by using visible spectroscopy. Contributions of the individual components of the composites to adsorption were also investigated. Although the MB adsorption capacity was extensively high for silica, it was moderate for the composite, most likely owing to the occlusion of pores of silica by plasticizer to some extent. The improvement of MB adsorption capacity of the composites as the silica ratio increased was explicitly deduced from the optical microscopy photographs. The diffusion coefficients of MB through the composites were 5 × 10−13, 6 × 10−13, and 3 × 10−13 m2 s−1 with regression coefficients of 0.73, 0.89, and 0.88 for 0, 2, and 16% silica-containing composites, respectively. Because of the slow diffusion of MB in poly(vinyl chloride)-silica composites, using them as dynamic column adsorbent was not practical. However, these versatile plastics can be used as plastic labels, colored clothing, leather substitutes, antimicrobial medical devices, and laser printable surfaces. J. VINYL ADDIT. TECHNOL., 21:42–50, 2015. © 2014 Society of Plastics Engineers

Polyoxometalates (POMs) were used, together with chitosan (CS), to obtain hybrid nanoaggregates. Three representative POMs were efficiently assembled into nanoparticles of few hundred nm diameter, featuring entangled ribbons substructure. In order to establish suitable preparation and stability conditions, the assemblies were characterized in solution by UV-Vis spectroscopy, dynamic light scattering and ζ-potential. The nanoparticles were tested against E. coli (106 CFU/ml) in aqueous solution, showing a synergic activity of the heteropolyacid H5PMo10V2O40 and CS. For such components, a highly porous and antibacterial film was obtained upon lyophilisation of the colloidal mixture., European Union's Seventh Framework Programme (246039); MIUR (FIRB) (prot. RBAP11ETKA)

Diblock copolymers of 4-vinylpyridine (4VP) and oligoethyleneglycol methyl ether methacrylate (OEGMA) were synthesized for the first time using RAFT polymerization technique as potential drug delivery systems. Effects of the number of ethylene glycol units in OEGMA, chain length of hydrophobic P4VP block, pH, concentration and temperature on the solution behavior of the copolymers were investigated comprehensively. Copolymer chains formed micelles at pH values higher than 5 whereas unimeric polymers were observed to exist below pH 5, owing to the repulsion between positively charged P4VP blocks. The size of the micelles was dependent on the relative length of blocks, P4VP and POEGMA. Thermo-responsive properties of copolymers were investigated depending on the pH and length of P4VP block. The increase in the length of P4VP block decreased the LCST substantially at pH 7. At pH 3, LCST of copolymers shifted to higher temperatures due to the increased interaction of copolymers with water through positively charged P4VP block., The Scientific and Technological Research Council of Turkey (110T570)

The isothermal crystallization and mechanical behavior of polycaprolactone (PCL) with zinc oxide (ZnO) with oleic acid and glycerol monooleate (GMO) were studied. Theoretical melting points calculated by the Flory-Huggins and Thompson-Gibbs models were thoroughly compared with differential scanning calorimetry experimental observations. The isothermal crystallization kinetic parameters by Avrami analysis showed that crystallization was controlled by nucleation, crystal growth was spherical, and the nucleation type changed between thermal and athermal nucleation. X-ray diffraction showed that when the additives were used together both the crystal thickness and the degree of crystallinity increased. A multiple-response regression analysis was made with the ZnO, oleic acid, and GMO concentrations as variables and the crystallinity as output. Interaction parameters by the Pukanzky model were calculated from the tensile strength at the yield point and indicated that the addition of oleic acid or GMO improved the interface between the ZnO particles and PCL., TUBITAK-110M157; Ege University Scientific Research Project Fund (BAP 09/MUH/093)

Methylene Blue (MB) adsorption studies were performed on flexible Polyvinyl Chloride/Silica composites which were obtained by using plastisol-plastigel technology. Change of MB concentration in aqueous phase as the adsorption process advanced was followed by using visible spectroscopy. The diffusion of MB through the composites exhibited non-Fickian behavior with a diffusivity of 10−11m2s−1. Making use of such PVC-silica composite sheets as column packing, the packing time will be reduced and the surface available for diffusion will be increased.

Tihminlioglu, Funda/0000-0002-3715-8253, WOS: 000424301800001, PubMed: 29196900, In this study, novel composites membranes composed of chitosan matrix and polyhedral oligomeric silsesquioxanes (POSS) were fabricated by solvent casting method. The effect of POSS loading on the mechanical, morphological, chemical, thermal and surface properties, and cytocompatibility of composite membranes were investigated and observed by tensile test, atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA), protein adsorption assay, air/water contact angle analysis and WST-1 respectively. Swelling studies were also performed by water absorption capacity determination. Results showed that incorporation of Octa-TMA POSS (R) nanofiller to the chitosan matrix increased the surface roughness, protein adsorption and swelling capacity of membranes. The addition of POSS enhanced significantly the ultimate tensile strength and strain at break of the composite membranes up to 3 wt% POSS loaded samples. An increase of about 76% in tensile strength and of strain at break 1.28% was achieved for 3 wt% POSS loaded nanocomposite membranes compared with chitosan membranes. The presence of POSS filler into polymer matrix increased the plasma protein adsorption on the surface. Maximum protein capacity and swelling was obtained for 10 wt% loaded samples. High cell viability results were obtained with indirect extraction of chitosan/POSS composites. Besides, cell proliferation and ALP activity results showed that POSS incorporation significantly increased the ALP activity of Saos-2 cells cultured on chitosan membranes. This novel composite membranes with tunable properties could be considered as a potential candidate for guided bone regeneration applications.

The purpose of this study is to develop a novel controlled release system based on pH-responsive polyacrylic acid (PAA)/lysozyme (LYS) complexes incorporated within a hydrophilic whey protein isolate (WPI) film matrix for active food packaging applications. Complex formation is simple under benign conditions that are suitable for preserving antimicrobial activity of the lysozyme. In addition, the pH-dependent charge density of complexes allowed a uniform distribution in the matrix. The properties of the complexes such as size, surface charge and hydrophilicity were varied by changing PAA/LYS ratio (0.1 and 0.3 w/w) and PAA molecular weight (2 kDa and 450 kDa). The effects of complex properties as well as mode of lysozyme incorporation into the films (100%-free, 50%-free+50%-PAA/LYS complex and 100%-PAA/LYS complex) on the LYS release rate, activity and antimicrobial efficacy of the films were investigated. The results have shown that ∼100% LYS loading into the complexes is possible regardless of PAA molecular weight or PAA/LYS ratio. Incorporating lysozyme into the film in complexed form extended its release time from less than 24 h up to 500 h and reduced its diffusivity from ∼10−9 to ∼10−13 cm2/s. The films including 50%-free-LYS+50%-PAA/LYS complex showed a 5.7 log reduction in bacterial population within 72 h whereas 100%-free-LYS containing film could not suppress Listeria innocua growth after 24 h. Overall, the results suggest that complexation of lysozyme with weak polyelectrolytes can be used as an effective strategy to achieve a long-lasting antimicrobial effect and that films prepared with such complexes have great potential as food packaging materials., Scientific and Technical Research Council of Turkey (110M440)

This chapter discusses the historical development of surface chemistry. During the period 1860 – 1912, the surface chemistry of catalysis made progress as a result of many experimental observations of scientists, such as in oxidation of hydrogen chloride, SO2oxidation to SO3, the reaction of methane with steam to form CO and H2, the oxidation of ammonia, ethylene hydrogenation, and the synthesis of ammonia. Catalytic technology has to be complemented by advancements in the chemical industry. The development of catalytic technology is closely related not only to the technological advances in the chemical industry, but also to significant political concerns. Most of the particulate materials used as heterogeneous catalysts present some limitations such as low stability, formation of agglomerates, and little selectivity, these conditions are likely to be due to weak surface conditions rather than bulk deficiencies themselves; surface optimization can improve the performance in materials that already have the necessary bulk properties.

We have shown that Ca(OH)2 solution is a natural stabilizer for CaCO3 particles. We designed a CO2 bubbling crystallization reactor to produce nano-CaCO3 particles in homogenous size distribution without aggregation. In the experimental set-up, the crystallization region was separated from the stabilization region. The produced nanoparticles were removed from the crystallization region into the stabilization region before aggregation or crystal growth. It was shown that rice-like hollow nano-CaCO3 particles in about 250 nm in size were produced with almost monodispersed size distribution. The particles started to dissolve through their edges as CO2 bubbles were injected, which opened-up the pores inside the particles. At the late stages of crystallization, the open pores were closed as a result of dissolution-recrystallization of the newly synthesized CaCO3 particles. These particles were stable in Ca(OH)2 solution and no aggregation was detected. The present methodology can be used in drug encapsulation into inorganic CaCO3 particles for cancer treatment with some modifications., Scientific and Technological Research Council of Turkey (MAG 110M104)

In this study, interactions of polyethylene glycol (PEG)-coated gold nanoparticles (AuNPs) with cells were investigated with particular focus on the relationship between the PEG layer properties (conformation, grafting density, and hydrodynamic volume) and cell cycle arrest, apoptosis, and DNA damage. Steric hindrance and PEG hydrodynamic volume controlled the protein adsorption, whereas the AuNP core size and PEG hydrodynamic volume were primary factors for cell uptake and viability. At all PEG grafting densities, the particles caused significant cell cycle arrest and DNA damage against CaCo2 and PC3 cells without apoptosis. However, at a particular PEG grafting density (∼0.65 chains/nm2), none of these severe damages were observed on 3T3 cells indicating discriminating behavior of the healthy (3T3) and cancer (PC3 and CaCo2) cells. It was concluded that the PEG grafting density and hydrodynamic volume, tuned with the PEG concentration and AuNP size, played an important role in particle-cell interactions., Izmir Institute of Technology (2011IYTE10)

Semi-volatile organic compounds were monitored over a whole year, by collection of gas and particle phases every sixth day at a suburban site in Izmir, Turkey. Annual mean concentrations of 32 polychlorinated biphenyls (∑32PCBs) and 14 polycyclic aromatic hydrocarbons (∑14PAHs) were 348 pg/m3 and 36 ng/m3, respectively, while it was 273 pg/m3 for endosulfan, the dominant compound among 23 organochlorine pesticides (OCPs). Monte Carlo simulation was applied to the USEPA exposure-risk models for the estimation of the population exposure and carcinogenic risk probability distributions for heating and non-heating periods. The estimated population risks associated with dermal contact and inhalation routes to ∑32PCBs, ∑14PAHs, and some of the targeted OCPs (α-hexachlorocyclohexane (α-HCH), β-hexachlorocyclohexane (β-HCH), heptachlor, heptachlor epoxide, α-chlordane (α-CHL), γ-chlordane (γ-CHL), and p,p′-dichlorodiphenyltrichloroethane (p,p′-DDT)) were in the ranges of 1.86 × 10−16–7.29 × 10−9 and 1.38 × 10−10–4.07 × 10−6, respectively. The inhalation 95th percentile risks for ∑32PCBs, ∑14PAHs, and OCPs were about 6, 3, and 4–7 orders of magnitude higher than those of dermal route, respectively. The 95th percentile inhalation risk for ∑32PCBs and OCPs in the non-heating period were 1.8- and 1.2–4.6 folds higher than in the heating period, respectively. In contrast, the 95th percentile risk levels for ∑14PAHs in the heating period were 4.3 times greater than that of non-heating period for inhalation, respectively. While risk levels associated with exposure to PCBs and OCPs did not exceed the acceptable level of 1 × 10−6, it was exceeded for 47 % of the population associated with inhalation of PAHs with a maximum value of about 4 × 10−6., Scientific and Technical Research Council of Turkey (ICTAG-C033); Izmir Institute of Technology (IYTE-BAP-20)