Optimizing Double Imprinted Polymeric Membrane (DIPM) for the simultaneous selective extraction of quercetin and caffeic acid

ABSTRACT

A double template imprinted polymeric membrane (DIPM) was fabricated using a surface polymerization technique on a poly(vinylidene fluoride) PVDF membrane using Quercetin (Qu) and Caffeic acid (CA) as the templates, ethylene glycol dimethacrylate (EGDMA) as the cross-linker and 4-vinylpyridine (4-VP) as the functional monomer via a thermal polymerization process. The polymerization of the imprinted membrane was characterized and optimized using critical variables such as concentration functional monomer and cross-linker for double responses on simultaneous binding capacity for Qu and CA using a central composite design (CCD). The optimized parameters were obtained from the concentration monomer and cross-linker at 4 mmol and 20 mmol, respectively; with the highest binding capacity for Qu (0.735 mg/g) and CA (1.1485 mg/g) achieved. The batch binding studies were conducted and simultaneous binding capacity showed that the DIPM obtained the highest Qu (4.3807 mg/g) and CA (4.0742 mg/g) adsorption at 24 mg/L when compare to NIM, followed by the Langmuir and Freundlich models, respectively. Finally, the imprinting factor (IF), selectivity (α), and distribution coefficient (K_D) of DIPM showed the highest Qu and CA adsorption when compared to its competitive components and NIM. The simultaneous binding performance studies have proven that a double imprinted membrane ability in recognition and adsorption for the desired template.

KEYWORDS:

• Molecularly imprinted membrane
• optimization CCD
• simultaneous extraction
• double template

Acknowledgments

The research was supported by Ministry of Higher Education of Malaysia through fundamental research (Grant No. FRGS/1/2016/TK05/UNIMAP/03/1)