Fabrication and Characterisation of MWCNT/Polyvinyl (PVC) Polymer Inclusion Membrane for Zinc (II) Ion Removal from Aqueous Solution

Nadia Aqilah Khalid; Noor Fazliani Shoparwe; Abdul Hafidz Yusoff; Ahmad Ziad Sulaiman; Abdul Latif Ahmad; Nur Aina Azmi

doi:10.3390/membranes12101020

Fabrication and Characterisation of MWCNT/Polyvinyl (PVC) Polymer Inclusion Membrane for Zinc (II) Ion Removal from Aqueous Solution

Membranes (Basel). 2022 Oct 20;12(10):1020. doi: 10.3390/membranes12101020.

Authors

Nadia Aqilah Khalid¹, Noor Fazliani Shoparwe¹, Abdul Hafidz Yusoff¹, Ahmad Ziad Sulaiman¹, Abdul Latif Ahmad², Nur Aina Azmi³

Affiliations

¹ Gold Rare Earth and Material Technopreneurship Centre, Faculty of Bioengineering and Technology, Jeli Campus, Universiti Malaysia Kelantan, Jeli, Kota Bharu 17600, Kelantan, Malaysia.
² School of Chemical Engineering, Engineering Campus, Universiti Sains Malaysia, Nibong Tebal 14300, Pulau Pinang, Malaysia.
³ Benua Sunda Cari Gali Sdn Bhd. No 6, Medan Pusat Bandar 1, Seksyen 9, Bandar Baru, Bangi 43650, Selangor, Malaysia.

Abstract

Heavy metal pollution has prompted researchers to establish the most effective method to tackle the impacts of heavy metals on living things and the environment, which include by applying nanoparticles. An example is the employment of multi-walled carbon nanotubes (MWCNTs) as an additive in an intermediate membrane or polymer inclusion membrane (PIM). The MWCNTs were added to enhance the properties and reinforce the transport performance of zinc (II) ion (Zn2+) removal from the source phase to the receiver phase by the PIMs. The present study constructed a membrane with a poly(vinyl chloride) (PVC)-based polymer, dioctyl phthalate (DOP) plasticiser, and bis-(2-ethylhexyl) phosphate (B2EHP) carrier incorporated with different concentrations of MWCNTs. The contact angle (CA), water uptake, ion exchange capacity (IEC), and porosity of the fabricated membranes were evaluated. The membrane was also characterised by employing scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and electrochemical impedance spectroscopy (EIS). Subsequently, the fabricated PIM (W1) and mixed matrix (MM)-PIM (W2−W5) samples were assessed under different parameters to acquire the ideal membrane composition and effectiveness. Kinetic modelling of Zn2+ removal by the fabricated PIMs under similar conditions was performed to reveal the mechanisms involved. The average removal efficiency of the membranes was >99% at different parameter conditions. Nevertheless, the W3 membrane with 1.0 wt% MWCNT immersed in a 5 mg/L initial Zn2+ concentration and 1.0 M receiver solution for seven hours at pH 2 demonstrated the highest percentage of Zn2+ removal. The experimental data were best fitted to the pseudo-first-order kinetic model (PFO) in kinetic modelling, and the permeability and flux of the W3 at optimum conditions were 0.053 m s−1 and 0.0532 mol m−2 s−1, respectively. In conclusion, the transport mechanism of Zn2+ was enhanced with the addition of the MWCNTs.

Keywords: adsorption; bis-(2-ethylhexyl) phosphate; extraction; multiwalled-carbon nanotubes; polymer inclusion membrane; zinc (II) ions.

Grants and funding

This research received funding from Ministry of Higher Education Malaysia (MOHE) via the Fundamental Research Grant Scheme (FRGS/1/2019/TK02/UMK/02/1).