Influence Of Carboxyl Research Articles

Carboxylated graphene oxide nanosheets as efficient electrodes for high-performance supercapacitors.

In the presence of dry ice, a series of graphitic materials with carboxylated edges (ECGs) were synthesized by ball milling graphite for varied times (24, 36, and 46 h). The influence of carboxylation on the physiochemical characteristics and electrochemical performance as effective electrodes for supercapacitors were assessed and compared with pure graphite. Several characterization techniques were employed to investigate into the morphology, texture, microstructure, and modification of the materials. Due to its interconnected micro-mesoporous carbon network, which is vital for fast charge-discharge at high current densities, storing static charges, facilitating electrolyte transport and diffusion, and having excellent rate performance, the ECG-46 electrode among the investigated samples achieved the highest specific capacitance of 223 F g−1 at 0.25 A g−1 current density and an outstanding cycle stability, with capacitance retention of 90.8% for up to 10,000 cycles. Furthermore, the symmetric supercapacitor device based on the ECG-46 showed a high energy density of 19.20 W h kg−1 at 450.00 W kg−1 power density. With these unique features, ball milling of graphitic material in dry ice represents a promising approach to realize porous graphitic material with oxygen functionalities as active electrodes.

INFLUENCE OF CARBOXYL-FUNCTIONALIZED GRAPHENE NANOPLATELETS ON THE THERMOMECHANICAL AND MORPHOLOGICAL BEHAVIOR OF SHAPE MEMORY NANOCOMPOSITES

INFLUENCE OF CARBOXYL-FUNCTIONALIZED GRAPHENE NANOPLATELETS ON THE THERMOMECHANICAL AND MORPHOLOGICAL BEHAVIOR OF SHAPE MEMORY NANOCOMPOSITES

Influence of carboxyl and amide groups on in vitro hemocompatibility of sulfonated polypropylene non‐woven fabric

ABSTRACTThe sulfonated polypropylene non‐woven fabric (PPNWF) was successfully fabricated via γ‐ray simultaneous radiation‐induced graft polymerization of acrylic acid (AA)/sodium styrenesulfonate (NaSS) and acrylamide (AAm)/NaSS. The existence of graft chains in both PP‐g‐P(AA‐co‐NaSS) and PP‐g‐P(AAm‐co‐NaSS) was proved by attenuated total reflection Fourier transform infrared spectroscopy and X‐ray photoelectron spectroscopy. Water contact angle measurement illustrated the sulfonated PPNWF owning good hydrophilicity. The in vitro hemocompatibility evaluation showed that both PP‐g‐P(AA‐co‐NaSS) and PP‐g‐P(AAm‐co‐NaSS) inhibited effectively the adhesion of platelets and were significantly compatible with erythrocytes. Moreover, no obvious difference was confirmed in the prevention of platelet adhesion and hemolysis ratio between carboxyl and amide groups. However, as compared with that of PP‐g‐P(AAm‐co‐NaSS), PP‐g‐P(AA‐co‐NaSS) exhibited outstanding anticoagulant activity via increased activated partial thromboplastin time and thrombin time. This result indicated that the carboxyl group but not amide group featured strong synergistic effect on the anticoagulant activity of sulfonated PPNWF. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45915.

Curing of epoxy/novolac system modified with reactive liquid rubber and carbon filler

The curing behaviour of epoxy resins modified with reactive liquid rubber, using a novolac resin as a hardner was studied by means of differential scanning calorimetry in isothermal (100, 130 and 150 °C) and non-isothermal conditions (2, 5, 10 and 15 °C min-1). The influence of carboxyl- (CTBN) and epoxy- (ETBN) terminated butadiene-acrylonitrile copolymers on the kinetic parameters and glass transition temperature (Tg) of cured epoxy systems was determined. The effect of grinded bituminous coal as an organic filler into epoxy network was also investigated. The carboxyl-end groups strongly enhanced the curing rate, in contrast to the epoxy-terminated rubber (ETBN) that had only a minor effect on the curing reactions. The presence of coal accelerated curing in its early stage. The Tg of completely cured epoxy was practically unaffected by the presence of carbon filler and reactive rubbers and was equal about 132 °C. The apparent curing activation energies were determined. A smaller activation energy was observed only for CTBN/epoxy/novolac system. The effect of reactive rubber and coal on the Charpy impact resistance of cured epoxy systems was also discussed.