Scaling Relations and Size Control of Block Ionomer Microreactors Containing Different Metal Ions

Abstract

Block ionomer micelles of polystyrene-b-poly(metal acrylate) containing a wide range of metal ions have been characterized, in order to establish a priori size control for a system of inorganic microreactors in which metal ions can be converted via simple chemistry to metallic or semiconducting nanoparticles. A variety of techniques have been employed, including size-exclusion chromatography (SEC), static light scattering (SLS), dynamic light scattering (DLS), and transmission electron microscopy (TEM). Scaling relations for aggregation numbers (Z) and ionic core radii (R core) as a function of the ionic block length (N B) have been determined: Z ∼ N B 0.74±0.08; R core ∼ N B 0.58±0.03, where the proportionality constants K Z ,ave and K R ,ave are dependent on the metal ion and decrease as Ni2+ > Cs+ > Co2+ > Ba2+ > Cd2+ > Pb2+. For most metal ions, linear plots of R core vs N B 0.58 yield correlation coefficients of r 2 of ca. 0.99, indicating excellent size control of ionic core radii. We also find that K Z ,ave decreases linearly with the crystal ionic radius (r ion) for block ionomers neutralized with metal acetates. We speculate upon the role of the metal ion on micelle growth. Comprehensive scaling laws have also been determined to include the soluble block length dependence, and similar exponents were found for most metal ions. DLS results show R g/R h values between those of stars and compact spheres. The coronal brush height (H) is found to scale as H ∼ Z 0.3±0.1 N A 0.9±0.2, in reasonable agreement with the Daoud and Cotton model for starlike systems.

Mesoscopic surface patterns formed by block copolymer micelles

“…Here, the ABC molecule acts as a compatibilizer, and very stable organic/inorganic hybrid materials are obtained. An illustrative example is the generation of fine metallic and oxidic nanoparticles within spherical ABC micelles in organic solvents, where the micelle acts as a so-called nanoreactor [6][7][8][9][10] . Such stabilized nanoparticles can carry very interesting material properties within polymer films, such as superparamagnetism 11) or catalytic activity 12) .…”

Metal Nanocrystals Embedded within Polymeric Nanostructures: Effect of Polymer-Metal Compound Interactions

“…The efficient impregnation of the nickel ions in the ionized PMAA network is attributed to the strong electrostatic complexation of the positive nickel ions by the negatively charged MAA units of the polymer [64]. The nickel content calculated by TGA was 32%, about 12% lower than the theoretically calculated value of 44% based on the monomer repeat unit/Ni = 3/1 mole feed ratio used.…”

Modification of hydrophobic polypeptide-based film by blending with hydrophilic poly(acrylic acid)

“…Based on their unique structures and properties, polypeptides and their copolymers have been investigated widely in the fields of functional biomaterials, protein simulation, polymer carriers for protein conjugates, macromolecular conformational study, catalysis, nanoreactors, drug delivery systems etc [9][10][11][12][13] . Also, for polypeptide films, an important application is for temporary artificial skin substrates in burn therapy [1,3] .…”