Adopting Sustainable Jatropha Oil Bio-Based Polymer Membranes as Alternatives for Environmental Remediation.

This study aimed to optimize the removal of Cu(II) ions from an aqueous solution using a Jatropha oil bio-based membrane blended with 0.50 wt% graphene oxide (JPU/GO 0.50 wt%) using a central composite model (CCD) design using response surface methodology. The input factors were the feed concentration (60-140) ppm, pressure (1.5-2.5) bar, and solution pH value (3-5). An optimum Cu(II) ions removal of 87% was predicted at 116 ppm feed concentration, 1.5 bar pressure, and pH 3.7, while the validated experimental result recorded 80% Cu(II) ions removal, with 95% of prediction intervals. A statistically non-significant term was removed from the analysis by the backward elimination method to improve the model's accuracy. Using the reduction method, the predicted R2 value was increased from -0.16 (-16%) to 0.88 (88%), suggesting that the reduced model had a good predictive ability. The quadratic regression model was significant (R2 = 0.98) for the optimization prediction. Therefore, the results from the reduction model implied acceptable membrane performance, offering a better process optimization for Cu(II) ions removal.

Highly Propylene-Selective Mixed-Matrix Membranes by in Situ Metal-Organic Framework Formation Using a Polymer-Modification Strategy.

Despite the potential of C3H6/C3H8 separation, there have been no industrial applications of zeolitic-imidazole framework-8 (ZIF-8) mixed-matrix membranes (MMMs) because of the moderate separation performances and several challenging processing issues. Herein, we present a new paradigm of MMM fabrication, named polymer-modification-enabled in situ metal-organic framework formation (PMMOF), enabling in situ formation of ZIF-8 fillers inside the 4,4-(hexafluoroisopropylidene)diphthalic anhydride 2,4,6-trimethyl-1,3-phenylenediamine polymer. PMMOF consists of four steps including hydrolysis of a polymer, ion-exchange, ligand treatment, and imidization. Each step was thoroughly analyzed and important processing parameters were identified, enabling the structural control of MMMs by PMMOF. The binary C3H6/C3H8 separation performance of the MMMs showed much higher separation factors than conventionally prepared MMMs at similar filler loadings, satisfying the commercial C3H6/C3H8 separation performance criteria. PMMOF was successfully applied for other MOFs, demonstrating that the process could be general. Finally, as a proof of concept, asymmetric mixed-matrix hollow fiber membranes (i.d. of 0.45 mm and o.d. of 0.63 mm) with ultrathin selective skin layers were prepared by PMMOF, showing C3H6 permeance of 2.17 GPU and C3H6/C3H8 separation factor of ∼20.