pH-Controlled Assemblies of Polymeric Amine-Stabilized Gold Nanoparticles

Abstract

The pH-controlled assembly of gold nanoparticles within a polymer-gold nanoparticle (AuNP) composite material is described. Poly(allylamine) (PAAm) is used as a reducing and stabilizing agent to generate a stable water-soluble polymer-AuNPs composite. The optical properties and the morphology of the composite material are sensitive to the solution pH due to structural changes of the polymer. As a result, the nanoparticles undergo reversible assembly/dispersion processes controlled by the solution pH. The role of the PAAm in the formation of the assemblies is confirmed by infrared spectroscopy and place exchange reactions.

Biotemplated Synthesis of Gold Nanoparticle–Bacteria Cellulose Nanofiber Nanocomposites and Their Application in Biosensing

“…[48] The amine groups of PEI are protonated at low pH values or neutral conditions, and PEI chains are fully stretched due to the electrostatic repulsion between the protonated amine groups. Streched PEI molecules may attach to the surface of BC nanofibers easily to act as linking molecules.…”

Preparation and catalytic properties of composites with palladium nanoparticles and poly(methacrylic acid) microspheres

“…Various supports have been employed to immobilize noble metal nanoparticles, such as carbon [14], metal oxides [15], molecular sieves [16], and polymers [17][18][19][20][21][22]. Polymers are advantageous because in addition to stabilizing and protecting the nanoparticles, they also offer unique possibilities for modifying and adjusting catalytic sites [20][21][22].…”

“…Shi et al further prepared gold nanoparticles and studied their catalytic activity by using different structure and morphological micelles as stabilizers [20][21][22]. However, the above mentioned metal nanoparticles are only used in certain solutions and discommodious for application [17][18][19][20][21][22].…”

Di-(2-ethylhexyl) dithiophosphoric acid surface protected gold nanoparticles: micellar synthesis, stabilization, isolation, and properties

“…The problem of the conservation of the initial size of nanoparticles during the isolation process is a very urgent task, so the isolation of the particles is performed in the presence of a protective agent preventing their agglomeration. Different types of protective reagents for gold nanoparticles are known, in particular citrate ion [6,7], alkylthiols [22][23][24], alkylthioacetates [25], organic amines [26,27], and phosphines [28].…”