Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2017 Jun 30;7(1):4426.
doi: 10.1038/s41598-017-04900-5.

Charge tunable thin-film composite membranes by gamma-ray triggered surface polymerization

Rackel Reis  1   2 , Mikel C Duke  3 , Blaise L Tardy  4 , Daniel Oldfield  5   6 , Raymond R Dagastine  4 , John D Orbell  3 , Ludovic F Dumée  7
Affiliations

Charge tunable thin-film composite membranes by gamma-ray triggered surface polymerization

Rackel Reis et al. Sci Rep. .

Abstract

Thin-film composite poly(amide) (PA) membranes have greatly diversified water supplies and food products. However, users would benefit from a control of the electrostatic interactions between the liquid and the net surface charge interface in order to benefit wider application. The ionic selectivity of the 100 nm PA semi-permeable layer is significantly affected by the pH of the solution. In this work, for the first time, a convenient route is presented to configure the surface charge of PA membranes by gamma ray induced surface grafting. This rapid and up-scalable method offers a versatile route for surface grafting by adjusting the irradiation total dose and the monomer concentration. Specifically, thin coatings obtained at low irradiation doses between 1 and 10 kGy and at low monomer concentration of 1 v/v% in methanol/water (1:1) solutions, dramatically altered the net surface charge of the pristine membranes from -25 mV to +45 mV, whilst the isoelectric point of the materials shifted from pH 3 to pH 7. This modification resulted in an improved water flux by over 55%, from 45.9 to up 70 L.m-2.h-1, whilst NaCl rejection was found to drop by only 1% compared to pristine membranes.

PubMed Disclaimer

Conflict of interest statement

The authors declare that they have no competing interests.

Figures

Figure 1
Figure 1
Flux and salt rejection for irradiation-induced grafted membranes; (a) grafting with 1 v/v% of VIM concentration, (b) 10 v/v% of VIM concentration, (c) 35 v/v% of VIM concentration and (d) salt rejection. Cross-flow desalination test conditions: 15 bar inlet pressure and 2,000 ppm NaCl solution at 25 °C. Details about error bars are provided in the supplement material.
Figure 2
Figure 2
Cross sections of TFC membranes at a fixed dose of 1 kGy. Top: series of pristine samples exposed to VIM solution and no irradiation and bottom: corresponding irradiated membranes.
Figure 3
Figure 3
Surface charge of amine grafted membranes using 1 v/v% of the VIM monomer (a) before permeation tests and (b) after permeation tests.
Figure 4
Figure 4
Water contact angle of membranes exposed to (a) 1 v/v% VIM solution, (b) 10% VIM solution, (c) 35% VIM solution and (d) MeOH/water.
See this image and copyright information in PMC

References

    1. Khulbe KC, Feng C, Matsuura T. The art of surface modification of synthetic polymeric membranes. Journal of Applied Polymer Science. 2010;115:855–895. doi: 10.1002/app.31108. - DOI
    1. Fujioka T, et al. Rejection of small and uncharged chemicals of emerging concern by reverse osmosis membranes: The role of free volume space within the active skin layer. Separation and Purification Technology. 2013;116:426–432. doi: 10.1016/j.seppur.2013.06.015. - DOI
    1. Childress AE, Elimelech M. Effect of solution chemistry on the surface charge of polymeric reverse osmosis and nanofiltration membranes. Journal of Membrane Science. 1996;119:253–268. doi: 10.1016/0376-7388(96)00127-5. - DOI
    1. He L, et al. Promoted water transport across graphene oxide–poly (amide) thin film composite membranes and their antibacterial activity. Desalination. 2015;365:126–135. doi: 10.1016/j.desal.2015.02.032. - DOI
    1. Al-Jeshi, S. & Neville, A. An investigation into the relationship between flux and roughness on RO membranes using scanning probe microscopy. Desalination <HT>189</HT>, 221–228, doi:10.1016/j.desal.2005.08.001 (2006).

Publication types

LinkOut - more resources