Nylon/Graphene Oxide Electrospun Composite Coating

Abstract

Graphite oxide is obtained by treating graphite with strong oxidizers. The bulk material disperses in basic solutions yielding graphene oxide. Starting from exfoliated graphite, different treatments were tested to obtain the best graphite oxide conditions, including calcination for two hours at 700°C and ultrasonic agitation in acidic, basic, or peroxide solutions. Bulk particles floating in the solution were filtered, rinsed, and dried. The graphene oxide obtained was characterized under SEM and FTIR techniques. On the other hand, nylon 6-6 has excellent mechanical resistance due to the mutual attraction of its long chains. To take advantage of the properties of both materials, they were combined as a hybrid material. Electrochemical cells were prepared using porous silica as supporting electrode of the electrospun nylon/graphene oxide films for electrochemical testing. Polarization curves were performed to determine the oxidation/reduction potentials under different acidic, alkaline, and peroxide solutions. The oxidation condition was obtained in KOH and the reduction in H2SO4solutions. Potentiostatic oxidation and reduction curves were applied to further oxidize carbon species and then reduced them, forming the nylon 6-6/functionalized graphene oxide composite coating. Electrochemical impedance measurements were performed to evaluate the coating electrochemical resistance and compared to the silica or nylon samples.

Transport of Protons and Capacitive Properties of the Nylon/Porphyrin/Graphene Oxide Coating

“…Different nylon/GO compounds are compared, and it can be seen that the concentration of GO and the electrospinning times are factors slightly affecting the changes in the system response. Dispersion in data observed, suggest complex overall electrochemical reactions taking place in the film-metal interphase (mid and lower frequencies), resulting in the promotion of a barrier effect [1,27]. This is also reflected in the capacitance values obtained and presented in table 1.…”

“…The combined presence of GO and porphyrins, in combination with electrospinning times present variable behavior in the impedance data obtained (table 1). This is possibly due to the difficulty of aggressive species diffusing through the tortuous coating paths, because of the physical barrier of the nylon and GO, and the electrical property of the porphyrins and GO that maintain the aggressive hydrogen ions over the surface, making difficult to reach the substrate [27,28].Characterization results show that the spatial position of amine groups of the porphyrins has important structural and textural effect on nylon and porphyrins integrated into the fibers.…”

“…The use of different species apparently induces the formation of a more homogeneous but rougher porous matrix than that of the H2T(o-NH2)PP species. The existence of four central nitrogens in the porphyrin macro-cycle makes the synthesis of metal complexes possible; these systems are suitable to be used with other cations such as transition metals for different applications such as electrochemical or supercapacitors [1,27,28]. …”

“…Studies that carry out this technique include: evaluation of water uptake, degradation with exposure time or coatings disbondment, estimation of corrosion rates at the metal/coating interface [1] and determination of the active area at which corrosion occurs, as well as evaluation of solar and fuel cell and battery charge-discharge cycles [2] .…”

Nanolif Yapılı Poli (Akrilonitril-Vinil Asetat)/ Grafen Oksit Yapıların Karakterizasyonu

“…Oksidasyon yöntemi ile elde edilen grafen türevlerinde oluşan fonksiyonel gruplar polimerler ile kolaylıkla bağ yapabilmektedir [5,9,10,11]. Bu sebepten polietilen (PE) [12], poliüretan (PU) [3], polimetilmetakrilat (PMMA) [3,12,13], polivinilalkol (PVA) [3,12], polibütilensüksinat (PBS) [3], polipropilen (PP) [12,13,14], poliakrilonitril (PAN) [12], termopoliüretan (TPU) [12,13], poliamid 6 (PA6) [13] gibi farklı polimerler ile nanokompozitleri güçlendirme maksatlı birçok çalışma yapılmış-tır [3,12].…”