Polymer brushes on graphene oxide for efficient adsorption of heavy metal ions from water

Abstract

The pollution of heavy metal ions in water poses a serious threat to human being and ecosystems. Here, we report polyamidoxime (PAO) brush grafted graphene oxide (GO) as a highly efficient adsorbent for extraction of toxic metal cations from water. Surface-initiated atom transfer radical polymerization was used to grow polyacrylonitrile (PAN) brushes on GO, followed by conversion of the nitrile groups in PAN into amidoxime groups, which had high binding affinity toward heavy metal cations. The PAO brush grafted GO demonstrated significantly fast adsorption kinetics and large adsorption capacity. At optimal pH 5, the PAO brush grafted GO can achieve maximum adsorption capacities of 116.7 mg g −1 for Pb(II), 258.6 mg g −1 for Ag(I), 192.2 mg g −1 for Cu(II), and 167.9 mg g −1 for Fe(III), which were significantly larger than those of small molecule functionalized GO. Mechanism analysis suggested that the enhanced adsorption performance was due to the myriads of functional groups in PAO brushes that were easily accessible to metal ions because of the swelling of the polymer brushes in water.

Efficient removal of uranium, cadmium and mercury from aqueous solutions using grafted hydrazide-micro-magnetite chitosan derivative

“…instrument (Thermo Fischer Scientific, Inc., Waltham, MA, USA) that was calibrated using Ag 3d 5/2 line (0.45 eV) and C 1s line (0.82 eV). The pH PZC was obtained using the pH-drift method [45]: a fixed amount of sorbent (100 mg) was stirred for 48 h with 50 mL of 0.1 M NaCl solutions at different initial pH values (pH 0 , in the range [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. The equilibrium pH was measured with a S220 Seven Compact pH/ Ionometer.…”

“…Chemically modified minerals were also efficiently designed for metal sorption [12]. New materials have been recently developed for increasing sorption capacities or improving uptake kinetics such as polymer brushes [11,13] or metal organic frameworks (MOFs) [14]. Functionalized activated carbons and multi-walled carbon nanotubes have also retained attention for the last decades [15,16].…”

Enhanced Thermal Conductivity of Polyamide-Based Nanocomposites Containing Graphene Oxide Sheets Decorated with Compatible Polymer Brushes

“…Another report showed the possibility to control chain length and grafting density of polystyrene brushes obtained using ATRP on graphene nanosheets [ 20 ]. Liu et al [ 21 ] reported the preparation of GO decorated with poly(amidoxime) brushes by grafting poly(acrylonitrile) chains via surface-initiated ATRP (SI-ATRP) and subsequent formation of amidoxime groups from the nitrile ones. Zygo et al [ 22 ] showed modifications of the GO surfaces by selected poly(methacrylates) at various grafting densities.…”

Scratch on Polymer Materials Using AFM Tip-Based Approach: A Review

“…Although a lot of applications have been achieved in the fields of nanooptics, nanofluidic, nano-electronic devices and so on [62,63], more and more novel applications needed to be discovered in the future so that the TBN method can be used in industrial engineering as early as possible. Moreover, AFM exhibits a huge potential in the development of polymer technology, especially for the emerging field of “polymer brushes”, which is a technique that grafts polymers on to solid substrates [64] and has been applied in the field of sewage purification [65], adsorption of charged biomolecules [66], lubrication [64], adhesion [67], colloidal stability [68] and biotechnology [69]. However, there is also a problem that the desorption of chains during and after the brush creation remains a common phenomenon by the existing method [68], and therefore, a reliable approach is required.…”