Variation of pH and Composite Dosage on the Photocatalytic Activity for ZnO/epoxy Nanocomposites

In this research, Zinc oxide (ZnO)/epoxy nanocomposite was synthesized by simple casting method with 2wt. % ZnO concentration. The aim of this work was to study the effect of pH and composite dosage on the photocatalytic activity of ZnO/ epoxy nanocomposite. Scanning electron microscopy (SEM) technique images proof the homogeneous distribution of ZnO nanoparticles in epoxy. A synthesized nanocomposite samples were characterized by Fourier Transform Infrared spectrometer (FTIR) measurements. Two spectra for epoxy and 2wt.% ZnO/epoxy nanocomposites were similar and there are no new bonds formed from the incorporation of ZnO nanoparticles. Using HCl and NaOH were added to Methylene blue (MB) dye (5ppm) to gat pH values 3 and 8. The degradation of the dye was 90.816% were pH =8 after 180 min. under sun-light. The degradation was 6.131% were pH=3 after 240 min. under sun-light irradiation. It is found that the base solution help in accelerating the photocatalytic process, pH with high value provides greater concentration of hydroxyl ions which interact with h+ to form hydroxyl radicals OH- that give an enhancement degradation rate of dyes. The dose of ZnO was increased from 3g to 6g with Methylene blue MB (5ppm) the degradation was 94.3755% after 240 min. under sun-light irradiation. This means that increasing the dose of ZnO, the photocatalytic activity will be increased.

Effects of the Interfacial Bonding Behavior on the Mechanical Properties of E-Glass Fiber/Nanographite Reinforced Hybrid Composites

The nanoparticles are incorporated into the composite to mark their unique properties. This work investigates the hybrid epoxy nanocomposite and the impact of nanographite reinforcement. The composite was prepared by using a mechanical stirring technique. The amount of nanographite was added in different volumes, i.e., 1.0, 1.5, and 2.0 wt.%. Results of mechanical and dynamic loading properties were analyzed in accordance to the quantity of nano-G. The fiber and matrix interfacial bonding enrichments were evident in high-resolution SEM images-tensile fracture surface. Finally, the optimum content of nanoparticle which impacts the sample greatly was found to be 1.5 wt.%.

Effects of Hybrid Graphene Oxide with Multiwalled Carbon Nanotubes and Nanoclay on the Mechanical Properties and Fire Resistance of Epoxy Nanocomposite

In this study, nanoclay I.30E and multiwalled carbon nanotubes (MWCNT) were hybridized with graphene oxide (GO) on Epikote 240 epoxy resin. Research results show that the hybridization between 0.5 wt.% GO with 1 or 3 wt.% nanoclay and 0.05 wt.% MWCNT has better mechanical properties and flame-retardant properties than the component materials. The combination of epoxy nanocomposite materials with flame-retardant additives such as nanoclay, MWCNT, and GO leads to improving flame-retardant and mechanical properties. Flame-retardant materials have no environmental problems and are nontoxic. Therefore, the flame-retardant additives studied in this work have great potential to become one of the promising flame-retardant hybrid materials. The study also showed that the result of the combination, the hybridization between the three components (nanoclay, MWCNT, and GO) synergized the mechanisms of fire resistance, creating insulating barriers, preventing objects from entering material exposed to heat and oxygen in the air.

Two modified multiscale modeling approaches for determination of two-phase and hybrid nanocomposite properties

In this paper, mechanical properties of thermoset epoxy based two-phase and hybrid nanocomposites containing carbon nanotubes (CNTs), and carbon nano diamond particles (CNPs) are determined using two different multiscale modeling approaches. The effects of resin crosslinking, interphase mechanical properties, and filler agglomeration on nanocomposite mechanical properties are investigated. First, the crosslinking between Diglycidyl ether of bisphenol A (DGEBA) resin and Diethylenetriamine (DETA) hardener is modeled considering different crosslinking forms and ratios using molecular dynamics (MD) simulations. Results indicate that resin elastic modulus increases with increasing the crosslinking ratio especially above 75%, but crosslinking form has an insignificant effect on resin modulus. Next, different nanofillers and their interphases are modeled using MD simulations to determine the representative volume element (RVE) and the effective fiber sizes and mechanical properties. The thickness of the interphase for each nano filler type is determined from the radial distribution function (RDF) diagram in order to determine the effective fiber volume more realistically. Then, the general Halpin-Tsai model is modified by adding an interphase volume factor and is used to determine two-phase and hybrid nanocomposite mechanical properties using effective nano filler properties. In addition, a new numerical multiscale modeling technique was developed which uses the MD-determined effective filler properties along with finite element method (FEM) to determine nanocomposite mechanical properties. Nanocomposites reinforced with aligned and randomly oriented reinforcements are modeled. Good agreement is observed between the two multiscale modeling techniques for the two-phase nanocomposite mechanical properties. Finally, the effect of filler agglomeration on nanocomposite properties is investigated. The results indicate that agglomeration decreases elastic modulus of CNT/epoxy nanocomposite. However, agglomeration does not have a significant effect on elastic modulus of CNP/epoxy nanocomposite.