Search

Addressing bacterial infection poses a notable challenge associated with medical implants, including magnesium (Mg)‐based implants used in orthopedic applications. The present work investigates the effect of graphene oxide (GO) and zinc oxide (ZnO) fillers on the microstructure, mechanical strength, corrosion resistance, antibacterial activity, and biodegradation properties of Mg alloy. The co‐inclusion of GO and ZnO in the nanocomposites (NCs) resulted in enhanced microhardness, compressive strength, corrosion performance, and hydrophobicity, with values rising from 51 to 82 Hv and 165 to 269 MPa, polarization resistance from 236 to 429 Ω cm2, and water contact angle from 46° to 87°, respectively. An exploration of the corrosion mechanism using electrochemical impedance spectroscopy and identification of NC characteristics revealed that the NC's compactness and the hindrance of corrosive ion penetration into the Mg matrix were attributed to the presence of GO/ZnO fillers. Additionally, the formulated NC improved MG63 cell proliferation and attachment. These findings indicate that the developed Mg‐based NCs, leveraging its antimicrobial properties through the inclusion of zinc oxide nanoparticles (ZnONPs) and graphene oxide nanoflakes (GONFs), holds significant potential as a degradable material for temporary orthopedic bone implants. [ABSTRACT FROM AUTHOR]

BACKGROUND: Membrane distillation (MD) for desalination encounters significant hurdles as a result of pore wetting, leading to reduced permeate flux or deterioration in permeate quality over time. Therefore, membranes used in MD must be highly hydrophobic to prevent liquid from entering the pores and contaminating the permeate stream. In this study, a thin layer of MoS2‐TiO2 composite was coated using poly (DOPA) as an adhesive to enhance attachment. Two coating methods, interlinking and layering, were compared to determine the most effective method for forming a thin hydrophobic coating layer onto PVDF‐PES hollow fiber membrane. RESULTS: Interestingly, this study revealed that increasing the number of dipping cycles led to higher flux, defying conventional expectations. This unexpected outcome is likely to have resulted from the thicker coatings creating a more hydrophobic surface, reducing water molecule adhesion and preventing wetting. Consequently, the membrane demonstrated enhanced flux despite its increased thickness. Among the membranes tested, the MoS2‐TiO2/PVDF‐PES membrane coated using the layering method exhibited the best performance, leading to a flux of 2.06 kg m−2 h−1 and 99.99% salt rejection. This superior performance can also be attributed to the membrane's hydrophobic properties, evident in its water contact angle (WCA) of 99°. By contrast, the interlinking method resulted in lower performance, with a permeate flux of 1.70 kg m−2 h−1 and 99.96% salt rejection, which is likely to have resulted from its lower WCA of 86°. CONCLUSION: The findings from this study suggest that the coating method has the potential to greatly improve membrane distillation performance through wettability modification rather than altering membrane porosity. © 2024 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

Membrane technology has been extensively applied for protein separation. A membrane with reliable filtration performance and high removal efficiency is required. In this study, an ultrafiltration (UF) membrane was fabricated by dry‐wet phase inversion to incorporate copper oxide nanoparticles (CuO NPs) with a different ratio of L‐cysteine (Cys) in polysulfone (PSf). The characterization of the membrane involves using scanning electron microscopy (SEM), water contact angle, water content, pore size, and porosity analysis. The membrane performance evaluation includes flux permeation and bovine serum albumin (BSA) removal as a protein foulant. The membrane antifouling feature was examined by dynamic filtration of BSA. It was found that the Cys to CuO NPs ratio of 1.7:1 gives an optimal value on flux permeation and protein removal. The membrane exhibited high removal of BSA with 96.3%, and optimum water flux was achieved at 173.3 L/m2h, respectively. The highest permeability of aqueous BSA permeate at 500 ppm was about 111 L/m2h and 82.5 L/m2h for 1000 ppm. The enhancement of PSf‐Cys‐CuO membrane performance could be due to its lower contact angle (68.7°), high porosity (68%), and ideal pore size (46 nm) as well as showing good morphological structure. Most significantly, the inclusion of Cys improves antifouling capabilities. The membrane showed a lower chance of fouling based on the evaluation of the relative flux reduction and flux recovery ratio. Hence, the availability of Cys has a better impact on the polymer‐based membrane and seems promising for protein separation applications. [ABSTRACT FROM AUTHOR]

BACKGROUND: The removal of lead ions (Pb2+) from industrial wastewater can be achieved using adsorption technology. Composites of zeolitic imidazolate framework‐8 (ZIF‐8) and graphene oxide (GO) were prepared via room temperature synthesis (RTS) using RO water as the solvent and by mixing GO with separated parts of ZIF‐8 precursors before its combination. Three weight percentages of GO, 10wt%, 30wt% and 50wt%, were used to synthesize ZGH10, ZGH30 and ZGH50 to determine optimum preparation and application conditions. Results: ZGH30 showed the most outstanding performance as an adsorbent for Pb2+ removal from aqueous solution. As captured by field emission scanning electron microscopy image, ZGH30 showed an adequate amount of ZIF‐8 grown on all surfaces of thr GO sheet, with an appropriate exposure of GO sheet layers for further Pb2+ interaction. The Pb2+ adsorption test revealed that ZGH30 obtained the optimum operating values between pH 5 and 6, using 10 mg dosage and it could remove ≤97% of 100 mg L−1 Pb2+. Additionally, ZGH30 achieved the most rapid equilibrium time within 10 min, similar to ZGH50, as compared to their individual components, ZIF‐8 (240 min) and GO (300 min). The mechanism of Pb2+ adsorption fitted well with a Langmuir isotherm and pseudo‐second‐order kinetic model. The theoretical maximum adsorption capacities obtained through Langmuir isotherm were 200, 454.55, 476.19, 555.56 and 454.55 mg g−1, for GO, ZH, ZGH10, ZGH30 and ZGH50, respectively. Conclusions: Therefore, ZGH30 hybrid successfully unleashed its potential as the adsorbent for wastewater treatment technology with improved performance after modification. © 2023 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

In this study, two different monomers, namely hexafluorobutyl acrylate (HFBA) and diethylaminoethyl methacrylate (DEAEMA) were individually used to modify graphene oxide (GO) nanosheets via environmentally friendly plasma enhanced chemical vapor deposition (PECVD) method. The results from instrumental analyses confirmed the successful deposition of respective functional material onto the nanomaterials. Modified GOs were used as the nano‐fillers to develop composite polyethersulfone (PES) ultrafiltration (UF) membrane with improved surface properties for oily solution treatment. All the developed membranes were characterized with a series of analytical instruments to support the findings of membrane filtration performance. The results indicated that the membrane incorporated with DEAEMA‐GOs (coated with hydrophilic polymer) could achieve better results in terms of oil rejection, antifouling resistance and water recovery rate than the membrane incorporated with HFBA‐GOs (coated with hydrophobic polymer). This is due to the reduced agglomeration between modified GOs as well as better interaction of hydrophilic‐coated GOs with polymer membrane. Compared to the pure water flux of the membrane incorporated with unmodified GO, the membrane incorporated with DEAEMA‐GO achieve approximately 85% higher value with oil removal rate remained almost unchanged (98.94% rejection). [ABSTRACT FROM AUTHOR]

Novel mixed matrix membranes (MMMs) were fabricated using Fe3O4, and Al2O3 nanoparticles (NPs) were added to the polysulfone (PSf) and N‐methylpyrrolidone (NMP) solution. The nanocomposite membranes were fabricated using the NIPS (non‐solvent induced phase separation) method. In order to create preferential permeation pathways for water across the MMMs, membrane formation is accomplished with an external magnetic field. Using magnetic casting cause the targeted placement of NPs in the best location and orientation. The performance of the prepared membranes was examined in terms of pure water flux and fouling parameters. Magnetic casting considerably increased pure water flux and decreased the total resistance of the optimum mixed matrix membrane, which contains 0.2% wt. of Fe3O4 NPs to 1175 L/m2h and 13.4 * 1011 (m−1), respectively. This is explained by the ordering of magnetic nanoparticles on the membrane sub‐layer cast under the magnetic field of 500 mT, which changed the sub‐layer structure. Less rough membrane surface of the mixed matrix membranes offered preferable anti‐fouling properties against fouling by BSA proteins. The characterization of fabricated membranes was carried out using field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), energy dispersive X‐ray (EDX), and water contact angle measurement methods. [ABSTRACT FROM AUTHOR]

Heavy metal pollution of water is a global concern, which adversely affects human health because of its resistance to biodegradation and thus its transmission in the food chain via bioaccumulation. Nano zerovalent iron (nZVI) is very effective for the removal of heavy metals and is cost effective in terms of production. However, the main problems of nZVI are agglomeration and ease of oxidation. Several stabilization materials have been implemented to limit the aggregation of nZVI, such as silica, activated carbon and biochar. In comparison, as a support material, biochar possesses a large surface area, high stability and strong adsorption capacity, as well as being obtainable from various types of materials. Thus, this work aims to establish the opportunities available on the use of biochar‐supported nZVI in utilizing its ability to stabilize and immobilize the nZVI. This review also reports the preparation, modification and surface enhancement of biochar, nZVI and biochar‐nZVI for practical use as adsorbents. This review shows that modifications of the nZVI surface can help in their stabilization and reduction of aggregation. Additionally, this review is able to increase one's understanding of heavy metal sorption behavior by biochar‐supported nZVI as it is the important as heavy metal sorption is driven based on biochar‐nZVI type and heavy metal species which involve numerous mechanisms, including physical binding, complexation, ion exchange, surface precipitation and electrostatic interactions. Furthermore, this research reviews the adsorption parameters, including the crucial adsorption mechanism of heavy metals onto biochar‐nZVI; the reusability of the biochar‐nZVI is also discussed in this work. © 2022 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

The substrate of forward osmosis (FO) thin‐film composite (TFC) membranes supports the formation of the selective layer. It can remarkably influence the structure as well as the physiochemical characteristics of the selective layer formed atop. Therefore, the improvement of TFC substrates in terms of its thickness, tortuosity and porosity can further fine tune the properties of the resultant TFC membranes. In this present study, TFC membrane comprising of polyamide selective layer and palygorskite‐chitin (PAL‐CH) containing polysulfone substrate was developed for FO desalination. The effects of PAL‐CH on the surface and structural properties of the substrate were examined. The FO desalination performance of the resultant membranes was evaluated in both active‐layer facing feed solution and active‐layer facing draw solution modes using NaCl as draw solution. In comparison with the un‐modified membrane, the TFC membrane with PAL‐CH embedded polysulfone substrate exhibited enhanced water flux and lower structural parameter. The incorporation of PAL‐CH hybrid nanomaterial resulted in improved flux of 34.39 L/m2 h1, which corresponds to improvement by 110% compared to that of pristine membranes. During the antifouling test, PAL‐CH‐S/PA membrane attained 97% water recovery while the pristine membrane attained 90% water recovery. [ABSTRACT FROM AUTHOR]

Since ancient times, wound dressings have experienced many significant improvements. Evolution began using natural materials to merely cover wounds and advanced to used innovative techniques that can be customized to perform different impressive functions. Recent wound dressings, which are made of electrospun polymers, contain different active compounds, such as antimicrobial agents, that aid in wound healing and prevent dehydration and infection. The mentioned issues may influence the healing process, leading even to serious health risks for the patients. As a result, scientists are now working on novel wound bandages with improved antimicrobial properties. Electrospun polymeric nanofibers, because of their structural similarities to normal skin's extracellular matrix (ECM), bactericidal activity, and appropriateness to distribute bioactive molecules to the wound location, are regarded as good resources for enhancing skin regeneration and controlling wound infection. Herein, the latest findings on approaches for producing antimicrobial polymeric nanofibers using electrospinning and related processes are discussed. Recent advances in antibacterial biopolymeric nanofibers incorporating antimicrobial nanoparticles (silver, zinc oxide, copper oxide, etc.) are discussed. This review paper may raise significant issues, encourage additional research, and offer important insight into the potential area of antibacterial polymeric fibers. [ABSTRACT FROM AUTHOR]

Hydrophilicity is one of the ideal properties for water treatment membrane. In addition, higher surface area with a porous structure results in extraordinary permeability and selectivity, thus making it a good candidate for water permeability. This study used iron oxide nanoparticles (IONPs) as polysulfone (PSf) membrane nanofillers to enhance the physicochemical properties. Nanofiber membranes were characterized in terms of morphology, wettability, and pure water permeability (PWP). The concentration of IONPs was varied from 0.5% to 2.0% (w/v). From the scanning electron microscope images, all produced membranes were smooth and contain bead‐free nanofibers. The produced nanofiber membrane with 1% (w/v) of IONPs concentration was found to be optimum since it had the highest porosity, lower contact angle, and desirable fiber thickness and diameter. In order to find the best PSf solution concentration, the loadings of PSf were varied from 18% to 27% (w/v). The PSf/IONPs with 25% (w/v) provided the best results in terms of fiber thickness and diameter, porosity and morphology. The contact angle also confirmed that in the presence of IONPs, the nanofiber structure produced with 25% PSf was less hydrophobic and had the highest PWP (70.27 L/m2 h bar). [ABSTRACT FROM AUTHOR]

In direct methanol fuel cells (DMFC), methanol crossover is a major issue which has reduced the performance of polymer electrolyte membrane (PEM) for energy generation. In this study, graphene oxide (GO) and conductive polyaniline decorated GO (PANI‐GO) were used as additives in fabrication of sulfonated poly(ether ether ketone) (SPEEK) nanocomposite PEM membrane to reduce methanol crossover. PANI‐GO was synthesized by in situ polymerization method and the formation of PANI coated GO nanostructures was confirmed by surface morphology and crystallinity analysis. The membrane morphology and topography analysis confirmed that GO and PANI‐GO were well dispersed on the surface of SPEEK membrane. 0.1 wt% PANI‐GO modified SPEEK nanocomposite membrane exhibited the highest water uptake and ion exchange capacity of 40% and 1.74 meq g−1, respectively. The oxidative stability of the nanocomposite membranes also improved. Lower methanol permeability of 4.33 × 10−7 cm−2S−1 was noticed for 0.1 wt% PANI‐GO modified SPEEK membrane. PANI‐GO modified SPEEK membrane enhanced the proton conductivity, which was due to the existence of acidic and hydrophilic group present in PANI and GO. PANI‐GO modified SPEEK membrane held higher selectivity of 1.94 × 104 S cm−3 s−1. Overall, these studies revealed that PANI‐GO modified SPEEK membrane is a potential material for DMFC applications. [ABSTRACT FROM AUTHOR]

Increasing demand for customized implants and tissue scaffolds requires advanced biomaterials and fabricating processes for fabricating three‐dimensional (3D) structures that resemble the complexity of the extracellular matrix (ECM). Lately, biofabrication approaches such as cell‐laden (soft) hydrogel 3D printing (3DP) have been of increasing interest in the development of 3D functional environments similar to natural tissues and organs. Hydrogels that resemble biological ECMs can provide mechanical support and signaling cues to cells to control their behavior. Although the capability of hydrogels to produce artificial ECMs can regulate cellular behavior, one of the major drawbacks of working with hydrogels is their inferior mechanical properties. Therefore, keeping and enhancing the mechanical integrity of fabricated scaffolds has become an essential matter for 3D hydrogel structures. Herein, 3D‐printed hydrogel‐based nanocomposites (NCs) are evaluated systematically in terms of introducing novel techniques for 3DP of hydrogel‐based materials, properties, and biomedical applications. [ABSTRACT FROM AUTHOR]

Poly(methyl methacrylate) (PMMA)‐based bone cements (BCs) can be defined as a family of materials that consist of powder and liquid phases which after mixing form a plastic paste that can self‐set once implanted in the human body. PMMA‐based BCs are easily molded and adapted to complex bone cavities or used in orthodontic applications to restore dental damage. The main advantages of the use of cement are the excellent primary fixation between bone and implant and, therefore, the faster recovery of the patient. Despite the initial success rate of implant fixation with BCs, they have some disadvantages such as local tissue damage due to exothermic polymerization reactions, mechanical mismatch between native bone and cement, lack of bone regeneration and bioactivity and poor mechanical properties which may cause the failure of the BCs. BCs are still considered as a top option for bone repair. Due to the disadvantages highlighted, research has focused on alternative materials used with PMMA‐based BCs. This review aims to critically review the BCs and emerging materials used in combination with PMMA‐based BCs. These materials include titania, apatite–wollastonite (A‐W), glass ceramic (GC) and hydroxyapatite (HA). The review discusses the properties of these materials and their pathway to clinical study. Among the various kinds of reinforcement, HA has been extensively used. So, in this review, we compare the effects of HA as reinforcement in PMMA‐based BCs. Upcoming study of PMMA‐based BCs should concentrate on trialing combinations of these reinforcing agents as this might improve beneficial characteristics. © 2020 Society of Industrial Chemistry [ABSTRACT FROM AUTHOR]

With the change in climate patterns, rapid industrialization, and population growth, the increasing water and energy demand became a major concern in the past decades. Desalination has been touted as the answer to the global water crisis, due to its capability in producing high‐quality fresh water from saline water. The continual research and innovations in the desalination field have resulted in the commercialization of large‐scale desalination in many water scarce regions. In the energetic context, all desalination processes are energy intensive. With the necessity to make desalination a more affordable and sustainable process, the energy efficiency of desalination is becoming an important topic. Herein, it is aimed to provide insights into the recent efforts and strategies established to tackle the energy‐related issues of both, thermal‐based and membrane‐based desalination processes. Depending on the principle of various commercial and emerging desalination processes, the directions of energy efficiency improvements, which include operating condition optimization, high‐performance material development, and renewable energy exploitation are discussed. The ideas and strategies reviewed herein, whether in their implementation or theoretical stage, are expected to provide insights into the possible improvement for application in commercial desalination plants. [ABSTRACT FROM AUTHOR]

Activated‐carbon nanofibers (ACNFs) provide a relatively new, modified structure of carbon‐based adsorbents that have the ability to adsorb carbon dioxide due to their high specific surface area, wide distribution of porous structures, and high volume of active sites. In this study, cost‐effective agricultural waste‐based graphene synthesized from rice husk ashes was used as additive to enhance the ACNF properties. ACNF/graphene (gACNF) is still a relatively unexplored adsorbent. The resultant gACNF exhibited better thermal stability properties, with higher yield, larger specific surface area, and higher micropore volume. These properties are the main factors contributing to their enhanced adsorption performance towards CO2. [ABSTRACT FROM AUTHOR]

Enhancing the performance of gas separation membranes is one of the major concerns of membrane researchers. Thus, in this study, poly(ether‐block‐amide) (Pebax)/polyetherimide (PEI) thin‐film composite membranes were prepared and their CO2/CH4 gas separation performance was investigated by means of pure and mixed gases permeation tests. To improve the properties of these membranes, halloysite nanotubes (HNT) were added to Pebax layer at different loadings of 0.5, 1, 2, and 5 wt % to form Pebax‐HNT/PEI membranes. Scanning electron microscopy, gas sorption, X‐ray diffraction, Fourier‐transform infrared, and differential scanning calorimetry tests were also performed to investigate the impact of HNT on structure and properties of prepared membranes. Results showed that both CO2/CH4 selectivity and CO2 permeance increased by adding HNT to Pebax layer up to 2 wt %. By increasing HNT loading to 5 wt %, the CO2/CH4 selectivity decreased from 32 to 18, while CO2 permeance increased from 3.25 to 4.2 GPU. Pebax/PEI and Pebax‐HNT/PEI membranes containing 2 wt % of HNT were tested using CO2/CH4 gas mixtures at different feed CO2 concentrations and feed pressure of 4 bar. The results showed that with increasing CO2 concentration from 20 to 80 vol %, CO2/CH4 selectivity of Pebax/PEI composite membranes increased by 19%, while, in Pebax‐HNT/PEI membrane, CO2/CH4 selectivity decreased by 40%. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48860. [ABSTRACT FROM AUTHOR]

BACKGROUND: In this work, a series of graphene oxide–polyethersulfone (GO–PES) composite flat sheet (FS) and hollow fiber (HF) membranes were fabricated by blending 0.5 and 1.0 wt% of GO into the PES matrix and utilized for oil–water separation. GO was first prepared and characterized by using Fourier‐transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), X‐ray diffraction (XRD) and thermogravimetric analysis (TGA) before being used as membrane fillers. RESULTS: Interestingly, although similar dope composition was used for the fabrication of HF and FS membranes, their morphology and pore size varied significantly owing to the way the membranes were fabricated. Significant enhancement of hydrophilicity was observed for both composite FS and HF membranes, where the water contact angle value decreased from 74.8° to 42.2° and 71.4° to 49.8°, respectively. The flux of the composite membranes increased up to 150% of the bare membranes especially when 1.0 wt% of GO was added. Although higher oil rejection (~99%) was observed for HF membranes that possess smaller pores, the permeation flux was maintained due to the improved flow dynamic. Lower oil rejection (up to 50%) was observed for FS membranes, which might be due to its big pore sizes particularly at the bottom surface. As more oil droplets formed on the membrane surface and prevented water molecules to pass through the membrane, fouling might occur rapidly. CONCLUSIONS: The results obtained in this work suggest that surface hydrophilicity, pore size of membranes and oil–water separation performances was greatly affected by membrane shape. Owing to many advantages of HF membranes, this type of membrane has great potential for commercial applications. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Bone cement synthesis through combination of polymers and bioceramics leads to the enhancement of mechanical and biological performances required for osteogenic properties and apatite‐formation ability with the aim of new bone growth. The purpose of the present study is to characterize a novel poly methyl methacrylate–poly caprolactone (PCL) bone cement containing baghdadite (BAGH) for orthopedic applications. Considerable enhancement in the mechanical properties was found in the cement containing BAGH compared to the cement without BAGH. Noticeably, favorable bioactivity was found in the bone cement containing BAGH, while the cement without BAGH presented poor bioactivity. The MTT assay illustrated that the MG63 osteoblasts' viability was noticeably improved by incorporation of BAGH into the cement. In addition, higher cell attachment and spreading were observed in the cement containing BAGH compared to the cement without BAGH. Hence, the synergistic effects of the cement containing BAGH including high mechanical properties, good bioactivity, and desirable cytocompatibility make it an attractive candidate for filling bone defects in orthopedic surgeries. [ABSTRACT FROM AUTHOR]

Removal by absorptive ceramic membranes can simultaneously absorb and separate metal ions from water. Alumina/yttria‐stabilized zirconia (Al2O3/YSZ) hollow‐fiber membranes, fabricated using phase inversion and sintering process, were deposited with iron oxide by an in‐situ hydrothermal process. The results showed that α‐Fe2O3 was produced and incorporated across the membranes. A reduction in flux was recorded with the deposition of α‐Fe2O3. However, it improved the adsorption capacity for heavy metal adsorption. The adsorption‐separation test demonstrated that the optimized membrane is able to completely remove Pb(II) ions after two hours. [ABSTRACT FROM AUTHOR]

Bacteria‐caused infection remains an issue in the treatment of bone defects by means of Mg‐Zn‐Ca alloy implants. This study aimed to improve the antibacterial properties of an Mg‐Zn‐Ca alloy by coating with chitosan‐based nanofibers with incorporated silver sulfadiazine (AgSD) and multiwall carbon nanotubes (MWCNTs). AgSD and MWCNTs were prepared at a weight ratio of 1:1 and then added to chitosan at varying concentrations (ie, 0, 0.25, 0.5, and 1.5 wt.%) to form composites. The obtained composites were ejected in nanofiber form using an electrospinning technique and coated on the surface of an Mg‐Zn‐Ca alloy to improve its antibacterial properties. A microstructural examination by scanning electron microscopy (SEM) revealed the diameter of chitosan nanofiber ejected increased with the concentration of AgSD‐MWCNTs. The incorporation of AgSD‐MWCNTs into the chitosan nanofibers was confirmed by Fourier transform infrared spectroscopy (FTIR). Examination of the antibacterial activity shows that chitosan nanofibers with AgSD‐MWCNTs can significantly inhibit the growth and infiltration of Escherichia coli and Staphylococcus aureus. Biocompatibility assay and cell morphology observations demonstrate that AgSD‐MWCNTs incorporated into nanofibers are cytocompatible. Taken together, the results of this study demonstrate the potential application of electrospun chitosan with AgSD‐MWCNTs as an antibacterial coating on Mg‐Zn‐Ca alloy implants for bone treatment. [ABSTRACT FROM AUTHOR]

The treatment for the bone diseases or defects such as tumor ablation, bone cysts and osteolysis were still challenging in clinical applications. Recently, the bone tissue engineering has emerged as a potential option for the treatment of bone defects. In this study, the nanofibrous composite scaffold consisting of polyurethane, olive oil, honey and propolis were fabricated through electrospinning method. The morphology of the nanofibrous scaffold indicated that nanofibers diameters were reduced with the addition of olive oil, honey and propolis into the Polyurethane (PU). The contact angle measurements showed that the behavior of PU/olive oil was found to hydrophobic (114° ± 1.528) and the PU/olive oil/honey/propolis scaffold rendered hydrophilic behavior (60° ± 1.528). FTIR and TG analysis revealed the interactions of PU with olive oil, honey/propolis and increased thermal stability of the composites. Atomic Force Microscopy (AFM) analysis displayed reduced surface roughness of the fabricated nanocomposite (PU/olive oil—469 nm and PU/olive oil/honey/propolis—449 nm) than the pristine PU (576 nm). The incorporation of olive oil, honey, and propolis resulted in the enhancement of the tensile strength (PU/olive oil—12.91 MPa and PU/olive oil/honey/propolis—14.346 MPa) compared with the pristine PU (7.12 MPa) as revealed in the mechanical testing. The blood clotting time of PU/olive oil (Activated partial thromboplastin time (APTT)—175 ±4 s and Partial thromboplastin time (PT)—103.3 ±3.512) was enhanced than pristine PU suggesting its improved anticoagulant behavior. Further, the developed scaffold showed low hemolytic index percentage (PU/olive oil—1.41% and PU/olive oil/honey/propolis—0.95%) than the control (2.48%) indicating its safety with RBC. Cytotoxicity test of the electrospun scaffold with human dermal fibroblast (HDF) cells using 3‐(4,5‐dimethylthiazol‐2‐yl)‐5‐(3‐carboxymethoxyphenyl)‐2‐(4‐sulfophenyl)‐2H tetrazolium assay demonstrated the non‐toxic and enhanced cell viability rates of HDF cells in developed scaffold than the pristine PU. Hence, the PU/olive oil/honey/propolis nanocomposite possessing better mechanical, physio‐chemical and biological properties might serve as a plausible candidate for bone tissue engineering. POLYM. COMPOS., 2018. © 2018 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

In this study, two types of novel hybrid nanomaterials, i.e., graphene oxide‐manganese ferrite (GMF) and titania nanotube‐manganese ferrite (TMF), were synthesized and used as adsorbent for removing arsenate (As(V)) ions from water via adsorption mechanisms. The synthesized nanomaterials were characterized by different techniques prior to use in the adsorption process. Batch adsorption studies revealed that the maximum adsorption capacities of GMF and TMF against As(V) are 102.0 and 80.8 mg g−1, respectively, when tested using feed water solution containing 400 ppm As(V). Two types of innovative hybrid nanomaterials, namely, graphene oxide‐manganese ferrite and titania nanotube‐manganese ferrite, with enhanced properties were synthesized and applied as adsorbent to remove As(V) from water. A high level of reusability after undergoing a simple desorption process coupled with the promising adsorption capacity make the hybrid nanomaterials highly potential. [ABSTRACT FROM AUTHOR]

Abstract: BACKGROUND: In this study, hydrophilic metal oxides such as TiO2, ZrO2 and ZnO were used as modifier for the preparation of polyethersulfone (PES) mixed matrix membranes (MMMs) for the filtration of cheese whey effluent. Nano metal oxide loading concentration was varied from 0.5 to 2.5 wt%. RESULTS: Characterization of metal oxide studies show that the particles are hydrophilic and nanoscaled. ZnO nanoparticles are in the form of nanocluster and of size 14.28–20.10 nm. Physio‐chemical characterization of PES MMMs indicated that the nano metal oxides dispersed well in the PES matrix. Contact angle decreased up to 59.88° for 1.5 wt% TiO2 embedded PES (TiO2ePES) MMMs. Also, 1.5 wt% TiO2ePES MMMs gives a higher water permeability of 4.62 × 10–7 m s–1 kPa–1. Among membranes, 1.5 wt% TiO2ePES, 2.0 wt% ZrO2ePES and 1.5 wt% ZnOePES MMMs showed better flux, lower percentage fouling and better rejection for individual whey proteins. CONCLUSION: The whey protein from cheese whey effluent was concentrated up to maximum of 43.9 mg L–1 using 2.0 wt% ZrO2ePES MMMs. It was found that 1.5 wt% TiO2ePES MMMs gives a higher average flux of 25.09 L m–2 h–1 and a lower flux reduction percentage of 39%. © 2018 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Abstract: In this work, ultrafiltration (UF) mixed matrix membranes (MMMs) incorporated with hydrophilic hydrous manganese oxide (HMO) nanoparticles were synthesized and used for the treatment process of a highly concentrated oily solution. The MMMs were fabricated via a phase inversion process and were characterized with respect to physiochemical properties and filtration performances. The results showed that the MMMs demonstrated higher water flux and better oil rejection rates compared to the control membrane (without HMO incorporation) when tested at three different oily solutions with oil concentration in the range of 5000–15 000 ppm. The membrane incorporated with the highest amount of HMO (labelled as MMM‐2) in particular showed the best results even when subjected to 15 000 ppm oily solution filtration, recording water flux of 32.2 L/m2 · h · bar and oil rejection of 82 %. The enhanced performance can be attributed to improved surface hydrophilicity coupled with better structural integrity and higher porosity that contributed to lower degree of oil molecules deposition and greater water transport rate. It was also reported that with the use of a feed spacer during the filtration process, the degree of flux deterioration of MMMs could be further reduced without compromising rejection. The findings of this work indicated the potential of MMMs for the treatment of highly concentrated oily effluent produced from industries, by producing permeate of high quality at reasonably good water permeability. [ABSTRACT FROM AUTHOR]

Abstract: BACKGROUND: Extracellular polymeric substances and microalgae stimulate membrane fouling during harvesting. The objective of the study was to compare the effect of pore formers on TiO2 embedded polyethersulfone mixed matrix membranes (MMMs) to harvest Coelastrella sp. FI69. The study experimented with hydrophilic additive (polyethylene glycol), polyelectrolyte additive (polyethylenimine), inorganic additive (zinc chloride) and charged polymer (sulfonated polyetherether ketone (SPEEK)) as pore formers. RESULTS: It was found that SPEEK/TiO2 combination enhanced the hydrophilic property of the PES membrane surface. Also, contact angle value (55.22°) was decreased by 1.38 times that of a neat PES (76.63°) membrane. Morphology studies indicated that the TiO2 particles dispersed well in the PES membrane matrix along with pore formers. The existence of super hydrophilic TiO2 supported the restriction of microalgae cell attachment on the membrane surface. The filtration of alginic acid sodium solution analysis showed that PES/SPEEK/TiO2 and PES/PEG/TiO2 membranes support higher flux with minimal fouling percentage. Microalgae filtration studies indicated that synergistic effect of both SPEEK and TiO2 on PES membrane exhibited higher water recovery percentage of 96% and equilibrium flux of 66 L m‐2 h‐1. CONCLUSION: Fouling propensity is significantly reduced in modified membranes. Future research on scale‐up of membranes for further microalgae dewatering applications is recommended. © 2017 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Abstract: For the first time, engineered osmosis was performed using commercial nanofiltration (NF) membranes for the treatment process of aerobically treated palm oil mill effluent (AT‐POME). Compared to conventional forward‐osmosis (FO) membranes with dense rejection layer, the NF‐like FO membranes offer a higher water flux with minimum reverse solute flux provided appropriate solutes like divalent salts or polyelectrolytes were used in the draw solution. Both NF membranes were able to treat the AT‐POME by completely preventing the color component from passing through the permeate side under FO and pressure‐retarded osmosis (PRO) orientation. The water fluxes of the membranes were higher under PRO orientation owing to the reduced internal concentration polarization effect. Relatively loose membranes for the engineered osmosis application could address severe surface fouling of membranes tested under pressure‐driven filtration. [ABSTRACT FROM AUTHOR]

Abstract: For the first time, thin‐film nanocomposite (TFN) nanofiltration membranes incorporated with graphene oxide (GO) were synthesized and used to separate phosphorus from water sources of varying properties. Prior to phosphorus removal tests, two different TFN membranes and one control thin‐film composite (TFC) membrane were subject to standard characterization in order to determine pure water flux, salt rejection, surface hydrophilicity, pore size, and porosity. By incorporation of GO, the water flux of composite membranes could be significantly improved with minimum decrease in salt rejection, mainly due to improved surface hydrophilicity coupled with enlarged pore size and overall structural porosity. Especially the TFN‐1 membrane was found to perform better owing to its good combination of water flux and solute rejection, higher water flux, and comparable phosphorus rejection in comparison to the TFC membrane. [ABSTRACT FROM AUTHOR]

Membranes are at the heart of hemodialysis treatment functions to remove excess metabolic waste such as urea. However, membranes made up of pure polymers and hydrophilic polymers such as polyvinylpyrrolidone suffer problems of low flux and bio-incompatibility. Hence, this study aimed to improve polysulfone (PSf) membrane surface properties by the addition of iron oxide nanoparticles (IONPs). Themembrane surface properties and separation performance of neat PSf membrane and membrane filled with IONPs at a loading of 0.2wt% were investigated and compared. The membranes were characterized in terms of morphology, pure water permeability (PWP) and protein rejection using bovine serum albumin (BSA). A decrease in contact angle value from 66.62° to 46.23° for the PSf/IONPs membrane indicated an increase in surface hydrophilicity that caused positive effects on the PWP and BSA rejection of the membrane. The PWP increased by 40.74% to 57.04 Lm-2 h-1 bar-1 when IONPs were incorporated due to the improved interaction with water molecules. Furthermore, the PSf/IONPs membrane rejected 96.43% of BSA as compared to only 91.14% by the neat PSf membrane. Hence, the incorporation of IONPs enhanced the PSf hollow fiber membrane hydrophilicity and consequently improved the separation performance of the membrane for hemodialysis application. [ABSTRACT FROM AUTHOR]

In this study, poly (1,8-octanediol citrate) (POC) was used to modify polyethersulfone (PES)-based membrane to enhance its hemocompatibility. Different compositions of POC (0-3%) were added into the polyethersulfone (PES) dope solutions and polyvinylpyrrolidone (PVP) was used as pore forming agent. The hemocompatible POC modified PES membranes were fabricated through phase-inversion technique. The prepared membranes were characterized using attenuated total reflectance-Fourier transform infrared (ATR-FTIR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), Atomic-force microscopy (AFM), contact angle, Zeta-potential, membrane porosity and pore size and pure water flux (PWF) and BSA rejection. The hemocompatibility of the modified PES membranes was evaluated by human serum fibrinogen (FBG) protein adsorption, platelet adhesion, activated partial thromboplastin time (APTT) and prothrombin time (PT), and thrombin-antithrombin III (TAT), complement (C3a and C5a) activation and Ca2+ absorption on membrane. Results showed that by increasing POC concentration, FBG adsorption was reduced, less platelets adhesion, prolonged APTT and PT, lower TAT, C5a and C3a activation and absorb more Ca2+ ion. These results indicated that modification of PES with POC has rendered improved hemocompatibility properties for potential application in the field of blood purification, especially in hemodialysis. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1510-1520, 2017. [ABSTRACT FROM AUTHOR]

BACKGROUND Gachsaran oil field is one of the largest oil fields in southern Iran and vast amounts of hydrocarbon contaminants are generated every year. Work is urgently required to devise effective methods to treat the produced water and high TPH content oily sludge under conditions that mimic the oil field. Bioremediation as an environmentally friendly and relatively cost-effective technique was examined in the present research. A continuous membrane bioreactor ( CMBR) and bio-slurry processes were utilized to treat the produced water and oily sludge, respectively. RESULTS The ability of consortium ( GACH-1) for degradation of crude oil under extreme conditions revealed that GACH-1 is able to grow at crude oil concentrations up to 11.3% (w/v), temperatures up to 73 °C, salinities up to 15.4%, and in the pH range 4-10. The results obtained from the CMBR tests demonstrated that although the COD of influent changed from 1800-2100 mg L−1, the COD of permeate was maintained at less than 125 mg L−1, which was equivalent to a removal efficiency of 94%. In the case of oily sludge, TPH content was reduced by 31.2% after bioremediation for 90 days. CONCLUSION Based on this approach, the consortium GACH-1 will be useful in clean-up of petroleum contamination in the Gachsaran oil field. © 2016 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

ABSTRACT In this study, the impact of several normal alkanes as additives on the structural parameters and the morphologies of flat sheet PES membranes were investigated. The asymmetric membranes were fabricated by phase inversion method. Also n-hexane, n-decane, and n-tetradecane were used as additives. The effects of different concentrations of these additives were investigated by producing the ternary phase diagrams. Further the membranes were characterized by means of solute transport test, contact angle, pure water flux, porosity measurement, and scanning electronic microscopy. It was expected that two distinct phase inversions to be occurred since both the polymer and the additives were insoluble in the coagulation bath. Observations revealed that n-hexane and n-decane were less effective compared with n-tetradecane in terms of binodal shifting toward PES/NMP axis. In conclusion, it was revealed that the coagulation bath immiscible-liquid additives had a major impact on the membranes structure in order to achieve the enhanced properties. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44509. [ABSTRACT FROM AUTHOR]

ABSTRACT In this study, self-synthesized copper(I) oxide (Cu2O) nanoparticles were incorporated in poly(ether sulfone) (PES) mixed-matrix membranes (MMMs) through the phase-inversion method. A cubic arrangement and crystallite size of 28 nm was identified by transmission electron microscopy and X-ray diffraction (XRD) for the as-synthesized Cu2O particles. The pristine PES membrane had a higher contact angle value of 88.50°, which was significantly reduced up to 50.10° for 1.5 wt % PES/Cu2O MMMs. Moreover, XRD analysis of the Cu2O-incorporated PES membrane exhibited a new diffraction pattern at 36.46°. This ensured that the Cu2O nanoparticles were distributed well in the PES matrix. Interestingly, the water permeability progressively improved up to 66.72 × 10−9 m s−1 kPa−1 for 1.5 wt % PES/Cu2O MMMs. Furthermore, the membrane performances were also evaluated with different feed solutions: (1) bovine serum albumin, (2) humic acid, and (3) oil-water. The enhanced rejection and lower flux reduction percentage were observed for hybrid membranes. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43873. [ABSTRACT FROM AUTHOR]

Appropriate membrane for blood contacting applications requires hemocompatibility and high permeation flux; it should inhibit proteins or platelets adsorption and still possess high permeability. Aiming to improve the polyethersulfone (PES) hollow fiber membrane hemocompatibility, sulfonated polyether ether ketone (SPEEK) is self-synthesized in the present research and added to PES in different ratios. Scanning electron microscopy images have revealed significant changes in PES membranes structure after addition of SPEEK, which can influence water permeation property of the membranes. Water contact angles of the membranes have reduced from 75° to 50° after addition of 4 wt% SPEEK. Influence of SPEEK addition on hemocompatibility of the PES membranes is evaluated via protein (bovine serum albumin) adsorption, platelet attachment, and coagulation time (APTT and TT) assays. Obtained results reveal that hemocompatibility of the modified hollow fiber membranes is enhanced as a result of emerging repulsive forces between negative charges on the membranes surface and negatively charge blood components. [ABSTRACT FROM AUTHOR]

The objective of this study was to fabricate dual-layer hollow fiber as a microreactor for potential syngas production via phase inversion-based co-extrusion/cosintering process. As the main challenge of phase inversion is the difficulty to obtain defect-free fiber, this work focuses on the effect of the fabrication parameters, that is, nonsolvent content, sintering temperature and outer-layer extrusion rate, on the macrostructure of the produced hollow fiber. SEM images confirm that the addition of nonsolvent has successfully minimized the finger-like formation. At high sintering temperature, more dense hollow fiber was formed while outer-layer extrusion rate affects the outer layer thickness. [ABSTRACT FROM AUTHOR]

Suitable membranes for blood-contacting medical applications need to be resistant in confrontation with blood proteins and cells, while possessing high blood compatibility and permeability at the same time. Herein, an overview of the recent advances and strategies that have been used to enhance the hemocompatibility of polymeric membranes is provided. The review focuses on two modification strategies: (i) physical modifications and (ii) chemical modifications. It also highlights the current progress in the design of hemocompatible-functionalized membranes for biomedical applications. Subsequently, the commonly applied biocompatibility tests are also discussed and finally the future perspectives of the application of polymeric membranes in the biomedical field are presented. [ABSTRACT FROM AUTHOR]

BACKGROUND: Functionalized activated carbon (FAC) was prepared by immobilizing the activated carbon (AC) synthesized from Acacia fumosa seeds in cacium-alginate beads. Synthesized FAC has been blended with polyphenylsulfone (PPSU) in the composition of 0.25 to 1wt% with an increment of 0.25wt% to prepare composite membranes of PPSU/FAC by wet phase inversion method. The existence of FAC in PPSU was confirmed by Fourier transform infra-red spectroscopy (FTIR) studies by the presence of characteristic functional groups of FAC. The influence of FAC on adsorption enhanced rejection of phenol during membrane filtration has been investigated. RESULTS: The hydrophilicity of PPSU/FAC composite membranes has been improved by FAC as there was a profound reduction in contact angle from71.8° to 43.8°.With the minimum loading of 0.25wt% of FAC in PPSU, themaximum adsorption of phenol has taken place suggesting that the better dispersion of minimal loading will offer higher accessibility to adsorptive sites. CONCLUSIONS: The adsorption of phenol on FACwas observed to be higher in PPSU/FAC compositemembranes when compared with FAC being used solely as an adsorbent. [ABSTRACT FROM AUTHOR]

ABSTRACT In this article, we present a development study of new membrane materials and enhancements of productive membranes to improve the current performance of polymeric membranes. Carbon membranes are a promising material for this matter as they offer an improvement in the gas-separation performance and exhibit a good combination of permeability and selectivity. Carbon membranes produced from the carbonization of polymeric materials have been reported to be effective for gas separation because of their ability to separate gases with almost similar molecular sizes. In this study, a carbon support membrane was prepared with Matrimid 5218 as a polymeric precursor. The polymer solution was coated on the surface of a tubular support with the dip-coating method. The polymer tubular membrane was then carbonized under a nitrogen atmosphere with different polymer compositions of 5-18 wt %. The carbonization process was performed at 850°C at a heating rate of 2°C/min. Matrimid-based carbon tubular membranes were fabricated and characterized in terms of their structural morphology, thermal stability, and gas-permeation properties with scanning electron microscopy, thermogravimetric analysis, Fourier transform infrared spectroscopy, and a pure-gas-permeation system, respectively. Pure-gas-permeation tests were performed with the pure gases carbon dioxide (CO2) and N2 at room temperature at a pressure of 8 bar. On the basis of the results, the highest CO2/N2 selectivity of 75.73 was obtained for the carbon membrane prepared with a 15 wt % polymer composition. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42394. [ABSTRACT FROM AUTHOR]

Herein we present a new approach for the complete removal of CrVI species, through reduction of CrVI to CrIII, followed by adsorption of CrIII. Reduction of chromium from water is an important challenge, as CrIV is one of the most toxic substances emitted from industrial processes. Chitosan (CS) thin films were developed on plain polysulfone (PSf) and PSf/TiO2 membrane substrates by a temperature-induced technique using polyvinyl alcohol as a binder. Structure property elucidation was carried out by X-ray diffraction, microscopy, spectroscopy, contact angle measurement, and water uptake studies. The increase in hydrophilicity followed the order: PSf < PSf/TiO2 < PSf/TiO2/CS membranes. Use of this thin-film composite membrane for chromium removal was investigated with regards to the effects of light and pH. The observations reveal 100 % reduction of CrVI to CrIII through electrons and protons donated from OH and NH2 groups of the CS layer; the reduced CrIII species are adsorbed onto the CS layer via complexation to give chromium-free water. [ABSTRACT FROM AUTHOR]

BACKGROUND Sulfonated poly (ether ether ketone) ( SPEEK) membranes and their modifications are viewed as arguably the most promising in microbial fuel cell (MFC) applications due to their non-fluorinated base, superior chemical stability, and lower costs compared with Nafion membranes. In this work, SPEEK membranes with different degrees of sulfonation ( DSs) (60% to 76%) and blended with charged surface modifying macromolecule (cSMM) were used as electrolytes in an MFC for simultaneous electricity generation and wastewater treatment. RESULTS Performance evaluation of newly fabricated membranes was carried out and was compared with that of Nafion 117. The MFC with SPEEK76/cSMM generated about 16.5% higher maximum power density (172.1 mW m−2) than that with Nafion 117 (143.7 mW m−2). In addition, the SPEEK76/ cSMM exhibited the highest coulombic efficiency (CE) of 17.6%, which was 21.6% higher than that of Nafion 117 (13.8%). Chemical oxygen demand ( COD) removal of all characterized membranes was above 80% in our particular MFC. CONCLUSION MFC is a suitable method for simultaneous wastewater treatment and electricity generation. SPEEK76/ cSMM is a promising membrane to be applied in MFC. © 2014 Society of Chemical Industry [ABSTRACT FROM AUTHOR]