Synthesis of amine‐functionalized block copolymers for nanopollutant removal from water

Abstract

Polyamines are rare in literature owing to increased reactivity, sensitivity to air and moisture, low stability, and processing difficulties. Here, we report the synthesis and characterization of highly processable polyamines and use them for the removal of dissolved metallic nanoparticles from water. Three amphiphilic block polyamines such as poly(N‐aminoethyl acrylamide‐b‐styrene), poly(N‐aminopropyl acrylamide‐b‐styrene), and poly(N‐aminoxylyl acrylamide‐b‐styrene) have been synthesized using atom transfer radical polymerization of ethyl acrylate and styrene followed by aminolysis of the acrylic block. The polymerization and properties of the polymers are studied using different physicochemical techniques. Surface morphology of films prepared from these block copolymers by dissolving in different solvents such as chloroform, tetrahydrofuran and N,N‐dimethylformamide, and drop‐casting polymers on a glass substrate show interesting porous films and spherical nanostructures. In addition, the amine‐functionalized block copolymers have been used for the removal of nanoparticles from water and show high extraction efficiency toward silver (Ag) and gold (Au) nanoparticles. All three amine‐functionalized block copolymers show higher extraction capacities (Qe) toward Au NPs (50–109 mg g−1) and Ag NPs (99–117 mg g−1). Our approach allows us to make amine‐functionalized block copolymers which are stable in air and can be easily processed in nonpolar solvents. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40943.

Use of porous cellulose microcapsules for water treatment

“…The citrate-capped NPs showed higher extraction capacities than PVP-capped ones owing to their negative surface charges. [21][22][23][24][25][26] PEI-MC showed higher extraction capacities for Ag-Cit, Ag-PVP, and Au-Cit NPs than other adsorbents. The extraction of Ag NPs was more efficient than Au NPs owing to stronger interaction between Ag and amine groups on the surface of microcapsules.…”

“…[13][14][15] The design and characterization of novel adsorbents such as functional polymers and biosorbents for detection and removal of nanopollutants from water is critical for providing clean drinking water to the general population. [21][22][23][24][25][26] A practical technology for pollutant removal from water should be cost-effective, efficient, and should not release chemicals into water or environment. [16][17][18][19][20] Adsorbents such as biosorbents, synthetic polymers and metal oxides were developed for the removal of silver (Ag NPs) and gold nanoparticles (Au NPs) from water.…”

Synthesis of amphiphilic block copolyamines via click reaction

“…Self-assembly of amphiphilic polymers into honey comb structures are influenced by many factors which include the effect of solvents, moisture and polymer concentrations [40]. Based on the reported mechanism of breath figure formation, [21,[41][42][43] it is expected that the polar amine functional groups organize on the surface of the films and are used for the extraction of nanoparticles from aqueous solution. In contrast to this, the polymer solutions in polar, high-boiling solvents such as DMF (0.1 mg mL À1 ) gave spherical particles upon evaporation of solvents under ambient conditions.…”

“…In addition to heavy metal ions, volatile organic compounds, organic dyes, microorganisms and other industrial pollutants, emerging toxic contaminants such as metal nanoparticles, which are tiny and reactive, warrant development of new materials for water purification. Recently, we have reported the synthesis and characterization of polyamines through functional group modifications on the polymer backbone and used them for removing nanoparticles from water [21].…”

Instrumental approach toward understanding nano-pollutants

“…Also, Wu and Chen employed UV-Vis spectrometry for detection of Cu nanoparticles with the size range of 5-15 nm at a higher concentration (up to 0.2 M) [142]. Qureshi et al synthesized polyamines for the removal of Au and Ag nanoparticles in the size range of 15-40 nm from aqueous medium at moderate pH, and they used UV-Vis spectroscopy to estimate the concentration of nanoparticles in solution [112]. In a similar study, Kumar et al functionalized carbon nanospheres for the removal of Au and Ag nanoparticles from water at ambient conditions and they used UV-Vis spectrophotometer for concentration measurement at ppm level [72].…”