Polyamidoamines based on castor oil‐styrene co‐oligomer/triethylenetetramine as curing agents in high‐performance epoxy coatings

Performance Evaluation for Ultra-Lightweight Epoxy-Based Bipolar Plate Production with Cycle Time Reduction of Reactive Molding Process

The commercial viability of fuel cells for vehicle application has been examined in the context of lightweight material options, as well as in combination with improvements in fuel cell powertrain. Investigation into ultra-lightweight bipolar plates (BPs), the main component in terms of the weight effect, is of great importance to enhance energy efficiency. This research aims to fabricate a layered carbon fiber/epoxy composite structure for BPs. Two types of carbon fillers (COOH-MWCNT and COOH-GNP) reinforced with woven carbon fiber sheets (WCFS) have been utilized. The conceptual idea is to reduce molding cycle time by improving the structural, electrical, and mechanical properties of BPs. Reducing the reactive molding cycle time is required for commercial production possibility. The desired crosslink density of 97%, observed at reactive molding time, was reduced by 83% at 140 °C processing temperature. The as-fabricated BPs demonstrate excellent electrical conductivity and mechanical strength that achieved the DOE standard. Under actual fuel cell operation, the as-fabricated BPs show superior performance to commercial furan-based composite BPs in terms of the cell potential and maximum power. This research demonstrates the practical and straightforward way to produce high-performance and reliable BPs with a rapid production rate for actual PEMFC utilization.

Simultaneous removal of Zn2+ and p-nitrophenol from wastewater using nanocomposites of montmorillonite with alkyl-ammonium and complexant

Three types of alkyl-ammonium with different branching chains and three complexants with different functional groups were used to prepare alkyl-ammonium or complexant intercalated montmorillonite nanocomposite (A-Mt or C-Mt). In addition, synergistic intercalated montmorillonite nanocomposites (A/C-Mt) with alkyl-ammonium along with complexant were also prepared. The adsorption performance of the various nanocomposites toward Zn²⁺ and p-nitrophenol (PNP) from simulated binary wastewater containing both Zn²⁺ and PNP were systematically investigated. Characterization of Mt nanocomposites showed that both alkyl-ammoniums and complexants were successfully intercalated into the interlayers of Mt. The surfactant loading amounts of the various nanocomposites were also determined and correlated with the resulting expansion of the interlayer spacing. It was found that intercalation of alkane (OTAC) and -SH (CSH) were conducive to the adsorption of Zn²⁺ while -C₂H₄NH (TETA) and all alkyl-ammoniums were beneficial for PNP adsorption. The extent of adsorption was found to be controlled primarily by pH, i.e., the higher pH had a good effect on the adsorption of both Zn²⁺ and PNP. The adsorption process of Zn²⁺ onto Mt nanocomposites was more in line with the Freundlich model (R² = 0.99), while the Langmuir model described the adsorption of PNP well (R² = 0.99). The adsorption kinetics could be well described by the Elovich equation (R² = 0.98) and the double-constant model (R² = 0.89). Chemical adsorption was determined to be the dominant process between the contaminant and Mt nanocomposite surfaces.