Addition of compatibilized nanoclay to GFRCs for improved izod impact strength and tensile properties

This research examines the effect of nanoclay silanization/compatibilization on the izod impact strength and tensile properties of epoxy-clay-based glass fiber reinforced composites (GFRCs). As per the existing literature, a key step in silanization of clay is washing of the silanized clay with acetone to remove the excess of silane molecules. However, contrary to this, the present research shows that acetone washing of the silanized clay lowers the tensile properties. GFRCs containing 2 phr nanoclay were processed. Three different montmorillonite clays were used in the initial investigations (two organically modified nanoclays designated as “CA” and “IE” and one unmodified nanoclay designated as “PG”). Silane concentration was varied in the range of 100–400% as proportion of nanoclay loading (i.e. 1X, 2X, 3X, and 4X). Silanization was validated by FTIR. XRD/TEM revealed increased d-spacing for silanized nanoclay and a partially exfoliated clay morphology in GFRCs. Highest izod impact strength (37% higher than the reference GFRC) without any loss in tensile properties was observed for GFRC reinforced with acetone washed 2X silanized “PG” nanoclay. GFRCs reinforced with silanized unwashed nanoclay (3X) showed 27% improvement in izod impact strength with significantly improved tensile strength (16% higher than the reference sample).

Improvement of Membrane Distillation Using PVDF Membrane Incorporated with TiO2 Modified by Silane and Optimization of Fabricating Conditions

The objectives in this study are to improve the performance of PVDF membrane by incorporating TiO2 and silane at various dosages and optimize fabricating conditions by using response surface methodology (RSM) for membrane distillation (MD) application. The PVDF membrane was synthesized by phase inversion method using various TiO2, silane and polymer concentrations. Membranes were characterized by performing contact angle measurements, SEM and FTIR observations. Ammonia rejection and permeate flux were measured by operating a direct contact distillation module treating ammonium chloride solution. A PVDF membrane created by adding TiO2 modified by silane improved membrane hydrophobicity. However, the effect of silane on membrane hydrophobicity was less pronounced at higher TiO2 concentrations. Highest ammonium rejection was associated with the highest membrane hydrophobicity. RSM analysis showed that fabricating conditions to achieve highest flux (10.10 L/m2·h) and ammonium rejection (100.0%) could be obtained at 31.3% silane, 2.50% TiO2, and 15.48% polymer concentrations. With a PVDF-TiO2 composite membrane for MD application, the effect of TiO2 was dependent upon silane concentration. Increasing silane concentration improved membrane hydrophobicity and ammonium rejection. RSM analysis was found to bea useful way to explore optimum fabricating conditions of membranes for the permeate flux and ammonium rejection in MD.

Correlation between silane concentration and temperature operated toward conductivity of well-synthesized chitosan-fly ash composite membrane

Composite membrane is synthesized using well-synthesized chitosan as matrix crosslink with fly ash as filler and modified using 3-glicydyloxypro-pyltrimetoxy silane coupling agent. XRD analysis is carried out to characterize fly ash. While, FTIR characterization is conducted to determine the interaction between chitosan matrix and fly ash that has been modified using silane. The emergence of a new absorption at wave numbers 1118.64 cm-1 shows the inter-action between silane and fly ash. In addition, the widening of OH absorption shows that hydrogen bonds are formed between the silane and chitosan. The interaction is also demonstrated by the evenly distributed hills and valleys on AFM topography analysis. Characterizing the composite membrane with TGA analysis is done to determine thermal stability. While, proton conductivity of the composite membranes are measured using EIS. The highest conductivity values are obtained with the addition of 5 % silane concentration of 2.75x10-4 S cm-1 at room temperature, 3.995x10-4 S cm-1 at 40?C, and 3.909x10-4 S cm-1 at 60?C. On the contrary, measurements at 80?C, decomposition in all composite membranes occur. Thus, the crosslinked composite membrane chitosan - fly ash prepared by silane-crosslinking technique has potential to be applied with polymer electrolyte membrane fuel cell (PEMFC).

Fused Deposition Modeling of Poly (Lactic Acid)/Walnut Shell Biocomposite Filaments—Surface Treatment and Properties

This paper presents the study of the properties of objects that were fabricated with fused deposition modeling technology while using Poly (lactic acid)/Walnut shell powder (PLA/WSP) biocomposite filaments. The WSP was treated while using NaOH followed by silane. The infrared spectrum of treated and untreated WSP was characterized. The result was that thermal and mechanical properties could be improved by adjusting the concentration of silane. The experimental results showed: the surface compatibility between WSP and PLA was dramatically improved through treatment with KH550. The crystalline, thermal gravity, and thermal degradation temperatures of biocomposite with untreated WSP were improved from 1.46%, 60.3 °C, and 239.87 °C to 2.84%, 61.3 °C, and 276.37 °C for the biocomposites with treated WSP, respectively. The tensile, flexural, and compressive strengths of biocomposites were raised each by 8.07%, 14.66%, and 23.32%. With the determined silane concentration, PLA/10–15 wt.% treated WSP biocomposites were processed and tested. The results showed that the tensile strength was improved to 56.2 MPa, which is very near to that of pure PLA. Finally, the porous scaffolds with controllable porosity and pore size were manufactured.