Original graphene oxide (GO) nanosheets were prepared using the Hummers method and found to easily aggregate in aqueous and cement composites. Using carboxymethyl chitosan (CCS) as a dispersant, few-layered GO nanosheets (1-2 layers) were obtained by forming CCS/GO intercalation composites. The testing results indicated that the few-layered GO nanosheets could uniformly spread, both in aqueous ...

Fly ash, which consists of hollow particles with porous shells, was introduced into polyurea elastomer. A one-step method was chosen to fabricate pure polyurea and the polyurea matrix for the composites based on Isonate® 2143L (diisocyanate) and Versalink® P-1000 (diamine). Scanning electron microscopy was used to observe the fracture surfaces of the composites. Particle size and volume fractio...

The effects of starch and aging on the mechanical properties of starch/poly(hydroxyester ether) (PHEE) composite materials were characterized. Native or modified cornstarches were extruded with PHEE. Composites were aged for up to 20 months at either 23°C and 50% relative humidity (RH) or over calcium sulfate to keep the composites dry. The tensile strength (TS) of the composites was affected b...

Three river basins, i.e., the Yangtze river, the Mississippi river and the Loire river, were presented as case studies to explore the association among atmospheric circulations, moisture exports and extreme precipitations in the mid-latitudes. The major moisture source regions in the tropics for the three river basins are first identified using the Tropical Moisture Exports (TMEs) dataset. The ...

this article aims to review various modes of fracture toughness of resin composites. also, this study intends to review the papers on the fracture mode, namely “fractography”, under scanning electron microscopy finding fracture initiation site, and the effect of filler content on the fracture toughness of resin composites. it will also review the effect of aging on the fracture toughness of res...

Bi-layer hybrid biocomposites were fabricated by hand lay-up technique by reinforcing oil palm empty fruit bunch (EFB) and jute fibre mats with epoxy matrix. Hybrid composites were prepared by varying the relative weight fraction of the two fibres. The physical (void content, density, dimensional stability), and chemical resistant properties of hybrid composites were evaluated. When the jute fi...

The main objective of this study was to determine the mold resistance and mechanical properties of fungicide-treated wood and bamboo flour/high density polyethylene (HDPE) composites. Zinc borate (ZB), 4,5-dichloro2-octyl-isothiazolone (DCOIT), zinc pyrithione (ZPT), and carbendazim (MBC) were used as fungicides. Then, treated and untreated samples were exposed to mold fungi (Aspergillus niger,...

The in vitro cytotoxicity of urethane dimethacrylate composites cured at different times by visible light and after different aging times and extraction treatments was evaluated using succinic dehydrogenase activity in the mitochondria of a fibroblastic cell line to reflect cell viability. In addition, extractable chemicals associated with cell response were identified. The composite samples we...

OBJECTIVES to complement our previous work by testing the null hypotheses that with short curing times and high DC, TPO-based resin composites would exhibit (1) higher polymerization stresses and consequently display (2) higher temperature rise and (3) higher flexural modulus, flexural strength and hardness, compared to a conventional CQ-based experimental composite. METHODS Two experimental ...

Fluorinated Bis-GMA was synthesized and used with other commercially available fluorinated monomers and diluents to prepare hydrophobic composites. The composites were formulated as one-paste systems and were polymerized using blue light. Mechanical properties and water-related qualities were determined. Fluorination generally improved the hydrophobicity of the composites, but there was no clea...