Medium-chain-length poly-3-hydroxyalkanoates-carbon nanotubes composite as proton exchange membrane in microbial fuel cell

Medium-chain-length poly-3-hydroxyalkanoates (PHA) and carboxyl group-functionalized multiwalled carbon nanotubes (MC) were used to fabricate a composite membrane for application in a double-chambered microbial fuel cell (MFC). MC was composited into PHA at 5%, 10%, and 20% w/w via ultrasound dispersion blending method. PHA-MC composite was compared with Nafion 117 as proton exchange membrane in MFC operated with palm oil mill effluent (POME) wastewater. The composite exhibited prerequisite separator membrane characteristics. The dispersion of MC in the polymer matrix increased its interfacial surface area and water uptake properties. PHA-MC10% membrane in MFC showed maximum power density of 361?mW/m², which was comparable with Nafion 117 (372?mW/m²). Internal resistance decrease, chemical oxygen demand (COD) removal, coulombic efficiency (CE), and conductivity of the PHA-MC10% were superior to Nafion 117. The environmental-friendly material could provide an alternative towards realizing practical MFC application.     

Trans-differentiation of human adipose-derived mesenchymal stem cells into cardiomyocyte-like cells on decellularized bovine myocardial extracellular matrix-based films

In this study, we aimed at fabricating decellularized bovine myocardial extracellular matrix-based films (dMEbF) for cardiac tissue engineering (CTE). The decellularization process was carried out utilizing four consecutive stages including hypotonic treatment, detergent treatment, enzymatic digestion and decontamination, respectively. In order to fabricate the dMEbF, dBM were digested with pepsin and gelation process was conducted. dMEbF were then crosslinked with N-hydroxysuccinimide/1-Ethyl-3-(3-dimethylaminopropyl)-carbodiimide (NHS/EDC) to increase their durability. Nuclear contents of native BM and decellularized BM (dBM) tissues were determined with DNA content analysis and agarose-gel electrophoresis. Cell viability on dMEbF for 3rd, 7th, and 14th days was assessed by MTT assay. Cell attachment on dMEbF was also studied by scanning electron microscopy. Trans-differentiation capacity of human adipose-derived mesenchymal stem cells (hAMSCs) into cardiomyocyte-like cells on dMEbF were also evaluated by histochemical and immunohistochemical analyses. DNA contents for native and dBM were, respectively, found as 886.11?±?164.85 and 47.66?±?0.09?ng/mg dry weight, indicating a successful decellularization process. The results of glycosaminoglycan and hydroxyproline assay, and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), performed in order to characterize the extracellular matrix (ECM) composition of native and dBM tissue, showed that the BM matrix was not damaged during the proposed method. Lastly, regarding the histological study, dMEbF not only mimics native ECM, but also induces the stem cells into cardiomyocyte-like cells phenotype which brings it the potential of use in CTE.     

Poly(lactide)/cellulose nanocrystal nanocomposites by high-shear mixing

There is currently considerable interest in developing stiff, strong, tough, and heat resistant poly(lactide) (PLA) based materials with improved melt elasticity in response to the increasing demand for sustainable plastics. However, simultaneous optimization of stiffness, strength, and toughness is a challenge for any material, and commercial PLA is well-known to be inherently brittle and temperature-sensitive and to show poor melt elasticity. In this study, we report that high-shear mixing with cellulose nanocrystals (CNC) leads to significant improvements in the toughness, heat resistance, and melt elasticity of PLA while further enhancing its already outstanding room temperature stiffness and strength. This is evidenced by (i) one-fold increase in the elastic modulus (6.48 GPa), (ii) 43% increase in the tensile strength (87.1 MPa), (iii) one-fold increase in the strain at break (∼6%), (iv) two-fold increase in the impact strength (44.2 kJ/m²), (v) 113-fold increase in the storage modulus at 90°C (787.8 MPa), and (vi) 10³-fold increase in the melt elasticity at 190°C and 1 rad/s (∼10⁵ Pa) via the addition of 30 wt% CNC. It is hence possible to produce industrially viable, stiff, strong, tough, and heat resistant green materials with improved melt elasticity through high-shear mixing.     

Correction to: Two New Co(II) Complexes of Picolinate: Synthesis,Crystal Structure,Spectral Characterization, α-Glucosidase İnhibition and TD/DFT Study

Journal of Inorganic and Organometallic Polymers and Materials -     

The Effect of Hydrothermal Aging on the Low-Velocity Impact Behavior of Multi-Walled Carbon Nanotubes Reinforced Carbon Fiber/Epoxy Composite Pipes

Chemical transmission lines, petroleum and natural gas lines, pressure vessels, and pipes used in thermal facilities are expected to maintain their mechanical properties for many years without being damaged and not to be corroded in working conditions. The composite materials are the right candidate for these harsh conditions due to their superior properties. Reinforcement of nanoadditives to composite materials improves both the mechanical properties and the resistance to environmental conditions, thereby increasing the lifetime. In this study, multi-walled carbon nanotube (MWCNT) reinforced [±?55°] carbon fiber/epoxy composite pipes produced with filament wound method were used. It was hydrothermally aged in 80 °C distilled water for 1, 2, 3 weeks in order to examine the effect of environmental conditions. In order to investigate its resistance against loads that may occur in working conditions, ring tensile tests (ASTM D 2290–16 procedure A), and low-velocity impact tests at 5, 10, 15 J, energy levels were carried out. The effect of hydrothermal aging on neat and MWCNT added epoxy composite had been examined by considering the aging period. Consequently, the impact resistance of neat and MWCNT added samples decreased with the aging process. Besides, tangential tensile strength loss was 17% in MWCNT reinforced sample and 13% in the neat sample.

     

Incorporation of pyridinic and graphitic N to Ni@CNTs: As a competent electrocatalyst for hydrogen evolution reaction

Cheap production of hydrogen (H₂) from eco-friendly routes is preeminent for solving future energy challenges. This study explores the hydrogen evolution reaction (HER) activity of nickel (Ni) nanoparticles and nitrogen doped carbon nanotubes (NiNCNTs), which are fabricated by a cheap and one-step pyrolysis method. The most active catalyst synthesized at 800°C exhibits an overpotential of 0.244 V to reach a current density of 10 mA cm⁻², Tafel slope of 93.3 mV dec⁻¹ and a satisfactory 10 hours stability. Low resistance and large ECSA value of the sample also favor the competent response for HER in alkaline media. The robust HER activity of the catalyst is as a result of the nickel nanoparticles which are the active spots of reaction; while the presence of well-developed nitrogen containing carbon nanotubes with large content of pyridinic and graphitic nitrogen may provide high-electron density and feasible routes for its transportation to deliver an outstanding HER performance.     

Predicting catastrophic temperature changes based on past events via a CNN-LSTM regression mechanism

Neural Computing and Applications - The modelling and prediction of extreme temperature changes in enclosed compartments is a domain with applications ranging from residential fire alarms,...     

In Situ Liquid-Cell TEM Observation of Multiphase Classical and Nonclassical Nucleation of Calcium Oxalate

Calcium oxalate (CaOx) is the major phase in kidney stones and the primary calcium storage medium in plants. CaOx can form crystals with different lattice types, water contents, and crystal structures. However, the conditions and mechanisms leading to nucleation of particular CaOx crystals are unclear. Here, liquid-cell transmission electron microscopy and atomistic molecular dynamics simulations are used to study in situ CaOx nucleation at different conditions. The observations reveal that rhombohedral CaOx monohydrate (COM) can nucleate via a classical pathway, while square COM can nucleate via a non-classical multiphase pathway. Citrate, a kidney stone inhibitor, increases the solubility of calcium by forming calcium-citrate complexes and blocks oxalate ions from approaching calcium. The presence of multiple hydrated ionic species draws additional water molecules into nucleating CaOx dihydrate crystals. These findings reveal that by controlling the nucleation pathways one can determine the macroscale crystal structure, hydration state, and morphology of CaOx.