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Graphene and its derivatives are an important material with many unique properties and potential in photocatalytic degradation and adsorption applications. Removal of oxygen-containing functional groups by reduction of graphene oxide (GO) is an interesting method that has been used frequently in recent years. The aim of this study is to examine graphene oxide reduction by using green synthesis and purple cabbage aqueous extraxt, which is an easy and effective method, and its use in photocatalytic removal applications. To optimize the synthesis conditions, the reaction temperature was first studied at 25, 50, and 100°C, and then the reaction time was studied for 1, 2, 4, and 6 hours. According to XRD, FTIR, UV/vis and SEM results, suitable experimental conditions for GO reduction are obtained at reaction temperature of 100°C and reaction time of 6 h. The obtained reduced graphene oxide (IGO) was used in photocatalytic degradation experiments in the aqueous solution of methylene blue (MM), an organic and cationic dye, under UV lamp and in the presence of H2O2. The results showed that after 120 min, IGO removed 85% of MM from the aqueous solution. It was determined that the MM photocatalytic degradation reaction kinetics of IGO matched the pseudo second-order reaction kinetics. [ABSTRACT FROM AUTHOR]

Superhydrophobic and oleophilic modification of commercial acoustic melamine foam (MF) was made in this study. The modification was carried out with chitosan (CHI) and silica particles (SiO2), by using both a layer-by-layer-like approach (LbL) and dip coating technique. Subsequently, 1-octadecanethiol was used as a secondary modification agent. QCM-D, SEM, and FTIR analyses confirmed that the coating was successfully performed. After the modification, the column wall thicknesses increased than that of MF and they ranged from 25% to 48% for modified MF with an LbL-like approach (MMF) and modified MF via dip coating technique (MMFd), respectively. The sorption experiments showed that modified MFs, which had a water contact angle (WCA) above 160°, could sorb several model pollutants (vegetable oil, chloroform, ethanol, and toluene) up to 76-130 times their original weight. It had been determined that MMF protects its open-pore structure better than that of MMFd, which indicated that MF has a more uniform pore structure after modification. Furthermore, after 10 cycles of the sorption and release process, there was no significant change in sorption capacity, and they preserved their mechanical stability and flexibility. [ABSTRACT FROM AUTHOR]

This study aims to optimize the synthesis of semiconductor zirconia (ZrO2) nanoparticles for future photocatalytic applications in degradation of pollutants in wastewater under ultraviolet (UV) light. The synthesis procedure of ZrO2 nanoparticles was optimized by examining the effects of synthesis methods (ultrasound-assisted, hydrothermal method in an autoclave and conventional precipitation), reaction time (2, 6, 10, and 18 h), ambient pH (3, 7, 10, 13), and surfactant type (anionic, cationic, and non-ionic), on the particle size and crystal phase of the nanomaterial. The characterization of the synthesized samples was performed by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy (EDS), high-contrast transmission electron microscopy (HR-TEM), and transmission electron microscope (TEM) analysis. Consequently, to synthesize ZrO2 nanoparticles with the smallest particle size and monoclinic/tetragonal phase, the experimental conditions were optimized as ultrasound-assisted synthesis method, pH 10, and 6 h reaction time without surfactant. Moreover, percentage yield, particle size, crystallinity, monoclinic and tetragonal volumes of ZrO2 nanostructures synthesized under optimized conditions were determined as 39.40%, approximately 9 nm, 46.77, 79%, and 21%, respectively. It has been determined that the particle sizes can be kept under control by controlling the phase composition of ZrO2 nanostructures by optimizing the synthesis parameters. Structural and morphological characterization results can be correlated to the photocatalytic application, showing the potential of this material for the photodegradation of organic dye pollutants. [ABSTRACT FROM AUTHOR]

Nowadays, in the treatment of such fungal infections, antifungal drugs in various forms are one of the most preferred methods. These medications can be in the form of creams and lotions, shampoos, pills, suppositories, powders, or sprays. The dose of the drugs is adjusted according to the type and growth area of the fungus, the severity of the symptoms, and the medical history of the patients. Dressing materials with antifungal properties are an alternative treatment method used for the treatment of fungal skin infections. These covers not only treat fungal infections but also prevent their spread. Within the scope of this study, polyurethane-based wound dressing materials (PU-UDA/PCL) with antifungal properties were developed. Electrospining method was used to produce these dressing materials and the surface area of the wound dressing material was increased, thereby increasing the effect of antifungal property. Polypropylene glycol, glycerol, and catechin as polyol were preferred in polyurethane (PU) synthesis. These structures were polymerized with isophorone diisocyanate and modified with 10-undecenoic acid. Obtained 10-undecenoic acid modified polyurethane (PU-UDA) structures were transformed into wound dressing structure with polycaprolactone (PCL) by electrospinning method. Structural, morphological, and thermal properties of the wound dressing materials were analyzed with different instrumental analysis methods. The antifungal activities of PU-UDA/PCL were tested. Antifungal tests were performed on C. albicans and C. tropicalis. Therefore, PU-UDA/PCL series could be used as an efficient antifungal agent. Finally, it was determined that the obtained 10-undecenoic acid-based polyurethane fibers have a suitable structure and feature for the treatment of many fungal infections. [ABSTRACT FROM AUTHOR]

Bacterial cellulose is used in different areas. One of these areas is using this material as bioadsorbent for decolorization of different dyes. In the study, Gluconacetobacter xylinus was used for obtaining bacterial cellulose (BC). The wet and dry forms of the BC were utilized as bioadsorbent for removal of the Reactive Blue 171 (C.I Chrocion Blue HERD) (200 mg/L), Remazol Brilliant Blue R (150 mg/L) (C. I Reactive Blue 19), and Chrocion Green H-E4BD (100 mg/L) dyes. The highest decolorization rates were obtained with wet BC at the first use as 51%, 52% and 54% for CBHERD, RBBR, and CH GREEN dyes after 24 hours of incubation at 30°C, 150 rpm, respectively. These values were 11%, 21%, and 20% for dry forms of BC at the end of the first use. At the same time, the structure and morphology of bacterial cellulose were determined by SEM, XRD, and FTIR analysis. [ABSTRACT FROM AUTHOR]

This study reports the preparation of poly(sodium-4-styrene sulfonate) (PSS) treated bentonite and clinoptilolite to prevent the agglomeration and sedimentation of these inorganic fillers during the preparation of hydrogel. For this purpose PSS treated fillers were prepared by using various techniques (dip and dry, hydrothermal, one-step ball milling and ultrasonication methods). The most suitable technique for preparing these PSS treated inorganic fillers (abbreviated as BP-dip and CP-dip) was the dip and dry method. BP-dip and CP-dip based polyvinyl alcohol/polyvinylpyrrolidone (PVA/PVP) composite hydrogels were prepared using the freeze/thawing method after the addition of one of BP-dip and CP-dip inorganic fillers in various amounts. The swelling properties, stability behaviors and Rhodamine B (RhB) adsorption of the composite hydrogels were studied. It was found that the swelling degrees of CP-dip and BP-dip based composite hydrogels with 25 mg of filler were higher than that of all other samples. The kinetic mechanism of RhB adsorption process and the related characteristic kinetic parameters were investigated by Pseudo kinetic models. The adsorption kinetics results for RhB adsorption were found best fitted with pseudo-second-order kinetics model. The maximum RhB adsorption capacity was determined to be for PVA/PVP-CP-dip25, which was 3.3 times higher than that of the unfilled PVA/PVP hydrogel. [ABSTRACT FROM AUTHOR]

In this study, the effects of starting material types on graphene oxide (GO) are reported with the aim of developing graphene (GR) synthesis. The GOs were prepared from natural graphite (NG) powder and graphite nanoplate (GNp) based on the Hummers method. Two kinds of GR were successfully synthesized using GOs, which were prepared from NG and GNp in the presence of hydrazine and ammonia for 24 h at a 100°C reaction temperature. The synthesized GOs and GRs were characterized by X-ray diffraction (XRD) techniques, Fourier transform infrared, highcontrast transmission electron microscopy (HCTEM), dispersive Raman spectroscopic analyses, and elemental analyses. HCTEM analyses of GOs and GRs exhibited largely folded, convoluted, and entwined GO and GR structures. The XRD and Raman analyses showed that the number of layers of GO1, GO2, GR1, and GR2 were 9.27, 13.53, 4.11, and 5.26, respectively. On the other hand, GR1, prepared from NG powder, showed much higher quality (peak intensities (ID/IG) = 1.53, C/O = 3.64) than GR2, which was prepared from GNp (ID/IG = 1.64, C/O = 3.17). Thus, this study provides a way to produce higher quality GOs and GRs. [ABSTRACT FROM AUTHOR]

The effects of incubation time, temperature, initial pH, and dye concentration on the indigo carmine decolorization activity of Pseudomonas aeruginosa ATCC 10145 and some factors on the decolorization potential of crude laccase enzyme obtained from Funalia trogii ATCC 200800 were comparatively investigated. This bacterium showed effective decolorization activity at all agitation and temperature values. Indigo carmine was greatly decolorized by P. aeruginosa at all pH values except pH 10. A decrease in decolorization activity occurred with increasing dye concentration, but this bacterium effectively decolorized the dye within 24 h. The decolorization process was through microbial metabolism, not biosorption. No decolorization or laccase activity could be obtained by the cell-free intracellular extract or culture filtrate of this bacterium. On the other hand, crude laccase effectively decolorized indigo carmine under highly acidic conditions, especially at pH 3.0 as 57% in 300 seconds. This activity decreased progressively due to the increase in pH values. In a short incubation period and at high temperature values, the crude laccase enzyme removed the color of the dye at 50 °C (56%), 60 °C (45%), and 70 °C (38%). These data are important for improving methods for decolorization of textile dyes used at high temperatures in various industrial applications. [ABSTRACT FROM AUTHOR]

Conductive poly(o-toluidine)/kaolinite composite was synthesized via chemical polymerization of o-toluidine in the availability of kaolinite using ammonium persulfate as oxidizing agent. To investigate the use of the prepared conductive composite as humidity and temperature sensor, the effect of polymerization conditions such as HCl, o-toluidine and oxidant concentrations on the amount of conductive POT contained in the composite and the conductivity values of composites were investigated. It was found that the composites with the highest poly (otoluidine) content (29.4%) and conductivity (8.3×10-4 Scm-1) were obtained by 0.2 M ammonium persulfate, 0.4 M o-toluidine and 1 M hydrochloric acid for 2 hours of continuous polymerization at 20 °C. The resistivity values of pure poly(o-toluidine) and poly (o-toluidine)/kaolinite composite were monitored during heatingcooling cycles in the range of 0-100 °C. Changes in resistivity for pure poly(o-toluidine) and poly(o-toluidine)/kaolinite composite with humidity 30-90% were examined and humidity sensor behavior was determined. Characterization of the prepared composite was performed by Fourier transform ınfrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and scanning electron microscopy techniques (SEM). [ABSTRACT FROM AUTHOR]

Funalia trogii and Trametes versicolor were grown on agro byproduct wheat bran moistened with various natural moistening agents, and their effects on laccase production under solid substrate condition were investigated. Laccase was the main enzyme detected under this condition. High levels of laccase activity were obtained with solid substrate cultures moistened with olive oil mill wastewater (OOMW) or alcohol factory wastewater (vinasse). Among the cultures without inducer, T. versicolor culture was detected as a more effective laccase producer than F. trogii culture. Copper and xylidine were used as laccase inducers, and copper induced laccase production more than xylidine. The maximum laccase activity was detected as 14.18 U/mL with F. trogii grown on wheat bran moistened with 5 mM CuSO4.5H2O added 25% vinasse. Azo dye decolorization activity of the supernatants from solid substrate cultures was also tested. While the use of 0.063 U/mL F. trogii laccase in reaction solution gave 66% decolorization in a minute, it was 14% for T. versicolor. This method can be a possible alternative for valorization of lignocellulosic materials and industrial wastewaters during solid substrate fermentation and for obtaining enzyme source with very high decolorization activity. [ABSTRACT FROM AUTHOR]

In this paper, an electrochemical sensor that can quickly and precisely determine the amount of caffeine (CAF) in various beverage using graphene based zirconia (ZrO 2) nanocomposite modified glassy carbon electrode (GCE) was produced. The particle size of the nanomaterials was determined as 5–7 nm by TEM and XRD techniques. The modified GCEs were prepared by dropping the nanomaterial dispersions onto GCE and electrochemical behavior of the electrodes was investigated using voltammetric techniques (CV and DPV). DPV result showed that xGnP-ZrO 2 nanocomposite modified GCE has a low detection limit (i.e., 1.19 × 10−8 M) in 0.1 M H 2 SO 4 medium at the range of 1 × 10−6-2x10−3 M of CAF concentration. A relative standard deviation (RSD) of an acceptable value below 5% was observed. It also exhibited good selectivity for components that might show common interference in the same medium as the CAF. The results revealed that proposed method has the potential for CAF detection. [Display omitted] • xGnP -ZrO 2 nanocomposite is synthesized by one-pot hydrothermal route. • xGnP-ZrO 2 modified GCE is prepared as an electrochemical sensor for CAF. • Low LOD and high sensitivity for CAF are achieved with the proposed electrode. • CAF could be quantified in beverages without any interference effect. [ABSTRACT FROM AUTHOR]

In the preparation of nanocomposites, the agglomeration of multi-walled carbon nanotubes (MWCNTs) in the composite due to their low colloidal stability limits their use in industrial areas. To overcome these problems, it is important to develop simpler, economical, high-yield and non-hazardous techniques to replace existing techniques with low yields, expensive additional equipment or hazardous liquids. This study explores how surfactants affect the macrodispersion of thermal stress-modified MWCNTs in cryogenic environments, focusing on their application in polymer film preparation. Firstly, optimal conditions for modifying MWCNTs through thermal stress were identified using liquid nitrogen. Parameters assessed included the number of cycles (2, 4, and 6), duration in liquid nitrogen (10, 20, and 30 min), and subsequent waiting time at room temperature (5, 12, and 20 min). Results showed that the highest surface area was obtained with 2 cycles, 20 min in liquid nitrogen, and 5 min at room temperature. Analytical techniques such as Brunauer-Emmett-Teller (BET), X-Ray Diffraction (XRD), High Contrast Transmission Electron Microscopy (CTEM) and Raman spectroscopy were used to evaluate the functionalization process's effects on MWCNTs' internal graphitic structure and physicochemical properties. CTEM micrographs indicated that thermal stress reduced the length of MWCNTs, while Raman analysis showed improved graphite quality. The modification process, carried out with 100 % efficiency and no sample loss, increased the BET surface area from 297.551 m2/g to 397.295 m2/g. The study also investigated the impact of surfactants (polyethylene glycol sorbitan monooleate-Tween 80, sodium dodecyl sulfate-SDS, and hexadecyltrimethylammonium bromide-CTAB) on MWCNTs' macrodispersion degrees (DM%) and energy band gaps via UV–visible (UV–Vis) absorption spectroscopy. CTAB provided the highest and most stable macrodispersion, reducing the energy band gaps of MWCNTs from 5.65–5.75 eV to 3.53–3.60 eV. CTAB showed excellent colloidal stability with a zeta potential of 44.2 mV, while SDS had −49.9 mV. Polyvinyl alcohol (PVA) polymer films, created using MWCNT solutions with optimal macrodispersion, were confirmed by Scanning Electron Microscope (SEM), Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimeters (DSC), and BET surface area analyses to have successfully and homogeneously incorporated MWCNTs. In addition to the superior properties of MWCNTs modified with the functionalization technique developed within the scope of this study by increasing their specific surface area and porosity, the excellent colloidal stability provided may have various effects in many industrial areas. These advantages enable MWCNTs functionalized with the developed technique to have a wider range of applications in industrial applications and provide more efficient and sustainable solutions. [Display omitted] • Modification of MWCNTs by rapid cooling-heating method was improved with success. • Developed a cost-effective, high-yield, and safe method to improve MWCNTs' colloidal stability. • The surface area of MWCNTs was increased by cryogenic modification without sample loss. • MWCNTs modified by the new technique can be uniformly incorporated into polymer films. [ABSTRACT FROM AUTHOR]

[Display omitted] • Propylthiouracil and levothyroxine caused growth retardation in embryos and tadpoles. • Propylthiouracil caused lethality and malformations in the FETAX test. • Significant enzyme inhibition was identified in stage 46 tadpoles exposed to drugs. • LDH induction in the AMA test indicates that drug exposure affects energy metabolism. • The developmental stages of Xenopus showed different sensitivities to drug exposure. The effects of two drugs containing the synthetic thyroid hormone levothyroxine (LEV) and an anti-thyroid drug containing propylthiouracil (PTU) on the three early life stages of Xenopus laevis were evaluated with the Frog Embryo Teratogenesis Assay- Xenopus , Tadpole Toxicity Test, and Amphibian Metamorphosis Assay using biochemical and morphological markers. Tested drugs caused more effective growth retardation in stage 8 embryos than stage 46 tadpoles. Significant inhibition of biomarker enzymes has been identified in stage 46 tadpoles for both drugs. AMA test results showed that LEV-I caused progression in the developmental stage and an increase in thyroxine level in 7 days exposure and growth retardation in 21 days exposure in stage 51 tadpoles. On the other hand, increases in lactate dehydrogenase activity for both drugs in the AMA test may be due to impacted energy metabolism during sub-chronic exposure. These results also show that the sensitivity and responses of Xenopus laevis at different early developmental stages may be different when exposed to drugs. [ABSTRACT FROM AUTHOR]

In this study, the laccase production ability of the newly isolated Trametes versicolor strain was investigated in three different fermentation processes. In all three fermentation processes, the fungus was able to produce the laccase enzyme. During the solid-state fermentation process 13.21 U/mL laccase activity was detected on the 20th day in the 10 mM coppercontaining medium, while this value reached to 27.30 U/mL in the medium containing 0.5 mM ABTS+10 mM copper. During the liquid batch fermentation process, laccase activity was significantly induced in the medium containing 1 mM copper and the laccase activities reached 2.25, 19.83 and 24.57 U/mL compared to the medium without copper on the 3rd, 6th, and 9th days, respectively. ABTS and xylidine induced the laccase production of this strain at a much lower level than copper. The liquid repeated-batch process also significantly induced the laccase production. While low level of enzyme activities were detected in a copper-free medium, laccase activities were induced in the copper-containing medium and the activity increased from 0.66 U/mL to 9.87 U/mL at the 6th use of the pellets. Copper was detected as an effective inducer for laccase production in all fermentation processes and activity staining after native polyacrylamide gel electrophoresis clearly showed the active laccase bands. The results revealed that this strain is a good laccase producer and the laccase production yield varies depending on the fermentation process, production time, and inducer used. [ABSTRACT FROM AUTHOR]

Commercially available multi-walled carbon nanotubes (MWCNTs), which are generally naturally intertwined, were cut by sudden, repeated exposure to oxidizing conditions in the air. This process has been proved to be an effective handle of producing open ended and medium level functionalization. Results showed that the typical closed graphite end caps for carbon nanotubes via functionalized with thermal stress (CNT-M) can be shorten long MWCNTs, while improving average graphite quality. These results were supported by the increase of Brunauer–Emmett–Teller (BET) surface area from 284.772 m2g−1 to 463.890 m2g−1. Copper oxide nanoparticles (CuO-PEGx) which were synthesized using polyethylene glycol (PEG) nonionic surfactants with different derivative (polyethylene glycol methyl ether methacrylate) and molecular weights (Mw: 200, 2000 and 5000), were encapsulated into CNT-Ms by simple wet impregnation technique. The filling capacity depended on the preparation conditions and particle size of CuO nanostructures. While other samples showed a multiple particle size distribution, only CNT-M-CuO-PEG950 sample indicated uniform particle size distribution with the smallest particles (3.6 nm) inside CNT-M channels. The BET surface areas of the nanocomposites (274.865–304.859 m2g−1) were lower than the surface area (463.890 m2g−1) of CNT-Ms while they were close and large to the surface area of MWCNTs (284.772 m2g−1). [Display omitted] • The using of thermal stress led to improving of the average graphite quality of MWCNTs. • The BET surface area of CNT-M (463.890 m2g−1) was achieved better within treated MWCNTs using other techniques. • PEG nonionic surfactants were used to synthesize smaller CuO nanoparticles. • CuO-PEG950 nanostructure was encapsulated inside CNT-M channels with uniform distribution and 3.6 nm average particle size. [ABSTRACT FROM AUTHOR]

In this study, a novel immobilization support for laccase was developed to enhance enzyme stability, efficiency and reusability. Firstly, Fe 3 O 4 magnetic particles were synthesized and modified by the co-precipitation route using thiolated chitosan (TCS). The support was characterized using several methods. Afterward, laccase was attached to the surface of functional support. The biochemical properties of the immobilized laccase were comprehensively investigated. It was observed that immobilized laccase achieved maximum activity at pH 4.0 and the optimum temperature was found to be 50 °C. After storage at +4 °C and ~25 °C for 4 weeks, the residual activity of the immobilized laccase was 87% and 80% of its initial activity, respectively. At 55 °C, the activity of immobilized laccase decreased to 73.4% in 180 min and after reused 20 times, the relative activity of immobilized laccase still was approximately 50% of its initial activity. Moreover, the textile dye (Reactive Blue 171 and Acid Blue 74) decolorization activity of immobilized laccase was also tested and it showed long-term textile dye decolorization activity. These results are promising for the use of laccase in industrial and biotechnological applications. Therefore, this functionalized magnetic hybrid composite might be used to immobilize laccase, an industrially important enzyme. • Fe 3 O 4 -TCS hybrid composite was synthesized for laccase immobilization. • Immobilized laccase showed high stability in a wider temperature and pH range. • The immobilized laccase exhibited well reusability after reused 20 times. • In addition, immobilized laccase showed long-term textile dye decolorization activity. [ABSTRACT FROM AUTHOR]

High cost and low operational stability are the most important challenges limiting the possible use of laccase in the removal of textile dyes. To overcome these challenges, in this study, polyvinylpyrrolidone (PVP)-coated magnetic nanoparticles (MNPs) were produced and characterized. To our knowledge, this is the first study to explore the feasibility of immobilizing a Trametes trogii laccase enzyme on Fe3O4/PVP MNPs. The characterization of samples and the successful immobilization of laccase were verified by characterization methods. Besides, the biochemical properties and stability of the Fe3O4/PVP/Lac were evaluated in terms of optimum pH, optimum temperature, thermostability, thermodynamic and kinetic parameters, storage stability, operational stability, and decolorization efficiency of two different textile dyes. The optimum activities were recorded at pH 2.5 °C and 30 °C. The Fe3O4/PVP/Lac displayed remarkable thermal stability and activation energy for denaturation, enthalpy, Gibbs free energy, and entropy results confirmed the enhanced stability of Fe3O4/PVP/Lac against high temperatures. Meanwhile, the Fe3O4/PVP/Lac retained about 58% of its original activity after seven consecutive reuses, while it retained up to 25% of its original activity after 28 d of storage at room temperature. Km and Vmax for the Fe3O4/PVP/Lac were calculated to be 126 µM and 211 µmol/min, respectively. Finally, after 8 and 6 cycles of repeated use, the Fe3O4/PVP/Lac still decolorized 32.34% and 32.23% of Remazol Brilliant Blue R (RBBR) and Indigo Carmine (IC), respectively. As envisioned, this study suggests a promising way to solve the problems of high price and poor operational stability of the enzyme during biocatalytic decolorization of textile dyes in wastewaters. [ABSTRACT FROM AUTHOR]

In spite of many works on the biodegradation of textile dyes and phenolic compounds, we propose a new, inexpensive, environmentally friendly, and sustainable material based on electrospun fiber and immobilized laccase. The polycaprolactone (PCL)/polyethyleneimine (PEI) electrospun fibers were optimized and prepared by electrospinning technique according to the operational parameters like PCL concentration (12 wt%), PEI concentration (10 wt%), voltage (16 kV), needle tip-collector distance (20 cm), and injection speed (0.7 mL/h). Next, characterization studies were performed to investigate the morphology and structure of the electrospun fibers without and with laccase. The crude laccase was obtained by cultivating the white rot fungus T. trogii (TT), and T. versicolor (TV). The resulting electrospun fibers showed a smooth surface with a mean diameter of around 560 nm, and larger diameters were observed after laccase immobilization. According to the results, immobilization increased the stability properties of laccase such as storage, and operational. For instance, the residual activity of the PCL/PEI/ TT L and PCL/PEI/ TV L after 10 repeated cycles, was 33.2 ± 0.2% and 26.0 ± 0.9%, respectively. After 3 weeks of storage, they retained around 30% of their original activity. Moreover, the PCL/PEI/ TT L and PCL/PEI/ TV L were found to possess high decolorization yield to remove Orange II and Malachite Green textile dyes from solutions imitating polluted waters. Among them, the PCL/PEI/ TT L exhibited the highest decolorization efficiencies of Orange II and Malachite Green after 8 continuous uses at pH 5 and a temperature of 50 °C, reaching over 86%, and 46%, respectively. Moreover, PCL/PEI/ TT L and PCL/PEI/ TV L effectively degraded the 2,6-dichlorophenol phenolic compound at an optimal pH and temperature range and exhibited maximum removal efficiency of 52.6 ± 0.1% and 64.5 ± 7.6%, respectively. Our approach combines the advantageous properties of electrospun fiber material and immobilization strategy for the efficient use of industrial scale important enzymes such as laccase in various enzymatic applications. [Display omitted] • Electrospun fibers were produced and used for immobilization of fungal laccases. • Immobilized laccases showed 30% of operational stability for up to 10 reuse cycles. • The highest decolorization efficiency was 86% and 46% for OII and MG, respectively. • In addition, the highest removal efficiency of 2,6-DCP was about 64.5% after 5 h. [ABSTRACT FROM AUTHOR]

Bilayer wound dressing systems consisting of various biopolymers have been preferred in biomedical applications due to its enhanced advantages in comparison with conventional systems. The aim of this research was to develop a novel bilayer wound dressing based on gelatin (G) and gellan gum (GG). The bilayer was composed of an upper layer impregnated with antibiotic drug sodium ampicillin and a drug-free lower sponge layer. The bilayer hydrogels were characterized by FTIR, TGA, DSC and SEM analyses including swelling behaviors and hydrolytic degradation tests. To achieve faster healing of the wound by prevention of the bacterial infection, the bilayer hydrogels were developed as antibiotic-releasing vehicles. Herein, release study of sodium ampicillin was performed in PBS to simulate the physiological micro-environment. Additionally, cyto-compatibility tests of L929 fibroblast cells showed the high proliferation and survival through drug-loaded GG and G hydrogels (GG-G-D) after 24h, 48h and 72h incubation. This novel GG-G bilayer hydrogel could be a good candidate as wound dressing. [ABSTRACT FROM AUTHOR]

In this study, graphene oxide (GO) was synthesized via modified Hummers method. The GO was grafted with poly(2,3,4,5,6-pentafluorostyrene) (PPFSGO) by surface initiated atom transfer radical polymerization (SI-ATRP). This material was used as a novel filler for thermoplastic polyurethane (TPU) to prepare composite films via solution casting method. FTIR, Raman and XRD spectroscopy analyses confirmed the formation of proposed hybrid structure. SEM analysis indicated that the GO layers of PPFSGO were exfoliated and decorated with weblike PPFS. Particularly, the contact angle measurements showed that the contact angle of TPU based composite films could be increased by 20% compared to bare TPU film with the incorporation of 10 wt% of PPFSGO while preserving thermal stability and electrically insulating properties. These results revealed that the herein proposed PPFSGO hybrid material is a promising candidate to adjust the wettability of TPU films without compatibility issues. [Display omitted] • GO was synthesized via modified Hummers method. • GO grafted poly(2,3,4,5,6-pentafluorostyrene) was prepared by SI-ATRP. • TPU based composite films were prepared by using the GO based material as filler. • Water contact angle of TPU based composite films was increased by 20%. [ABSTRACT FROM AUTHOR]

This study aims to present a simple and effective carrier matrix to immobilize laccase as opposed to complex and tedious immobilization processes and also to use it in the removal of textile dyes. For this purpose, Cobalt (Co) and Copper (Cu) based metal-organic frameworks (MOFs) were prepared and laccase was immobilized on two different MOFs via encapsulation. The characterization outcomes showed that laccase was well immobilized into MOF supports. Optimum pH and temperature were found for Lac/Co-MOF (pH 4.5 at 50 °C) and Lac/Cu-MOF (pH 5.0 at 50 °C). The Km (0.03 mM) and Vmax (97.4 μmol/min) values of Lac/Cu-MOF were lower than those of Lac/Co-MOF (Km = 0.13 mM, Vmax = 230.7 μmol/min). The immobilized laccases showed good reusability as well as improved resistance to temperature denaturation and high storage stability. For instance, the Lac/Co-MOF and Lac/Cu-MOF retained more than 58% activity after 4 weeks of storage at room temperature. Meanwhile, Lac/Co-MOF and Lac/Cu-MOF maintained 56.5% and 55.8% of their initial activity, respectively, after 12 reuse cycles. Moreover, thermal deactivation kinetic studies of immobilized laccases displayed lower k value, higher t 1/2 , and enhancement of thermodynamic parameters, which means better thermostability. Finally, the decolorization activities for the Lac/Co-MOF were 78% and 61% at the 5th cycle for Reactive Blue 171 and Reactive Blue 198, respectively. In conclusion, it can be inferred that the MOFs are more sustainable and beneficial support for laccase immobilization and they can be efficient for removing textile dyes from industrial wastes. [Display omitted] • Co-MOF, and Cu-MOF were suggested to immobilize laccase. • Immobilized laccases were produced by encapsulation. • The immobilized laccases exhibited enhanced thermal and storage stability. • The immobilized laccases maintained more than 55% activity after 12 cycles. • Reactive Blue 171 and Reactive Blue 198 were decolorized by immobilized laccases. [ABSTRACT FROM AUTHOR]

• Laccase was immobilized onto MOF-808 via adsorption for the first time. • Lac/MOF-808 displayed high thermal stability and storage stability. • The Km value of Lac/MOF-808 was 2.0-fold higher than free laccase. • Lac/MOF-808 retained 40 % of its initial activity after 10 cycles of recycling. • Lac/MOF-808 removed 56.7 % and 77.2 % of RB 171 and RB 198, respectively. Laccase enzyme sees application demand in many industries such as textile, food processing, wood processing, pharmaceutical, and chemical. However, it becomes difficult to maintain the enzymatic activity of laccase under harsh reaction conditions and even after several biocatalytic cycles. Therefore, suitably prescribed supports are crucial to ensure that the catalytic activity and reusability of the immobilized laccase are maintained at high levels. The present study highlights the development and dye decolorization application of an enzyme carrier matrix employing a Zr-based metal-organic framework (MOF), MOF-808, with hierarchical porosity for the immobilization of laccase from Trametes trogii. The immobilization efficiency for Lac/MOF-808 was found to be 70.83 ± 1.98 %. Lac/MOF-808 exhibited optimal catalytic temperature at 60 °C, while the optimal catalytic pH was 4.5. Due to recoverable properties from the carrier matrix the recycle test was satisfactory for the Lac/MOF-808, being reused 7 times without losses greater than 50 % of residual activity. Stored at 25 °C, Lac/MOF-808 retained 30 % of its activity during 4-weeks period. A kinetic study was carried out for Lac/MOF-808 monitoring the oxidation reaction of ABTS. The K m value was 0.070 mM and the V max was 87.7 µmol min−1 g −1. Kinetic investigations, on the other hand, demonstrated a decrease in K m following immobilization, signifying a higher affinity for substrate. The Lac/MOF-808 maintained its decolorization efficiency even after eight reaction cycles, exhibiting a remarkable activity of 56.7 % and 77.2 % against Reactive Blue 171 and Reactive Blue 198, respectively. Hence, the described Lac/MOF-808 might be an ideal candidate for efficient dye decolorization applications. [Display omitted] [ABSTRACT FROM AUTHOR]