Concentration dependent response to pH modification and salt addition of polymeric dispersions of C60 fullerenes

Micellization of a di‐block copolymer in ethylene glycol and its utilization for suspension of carbonaceous nanostructures

“…To increase the inherently low contrast of the polymer assemblies, ammonium molybdate (AM) was added to the relevant polymer solution (and suspensions of nanostructures). As was reported by us before, the AM acts as a positive stain, leading to contrast enhancement. The AM solutions were prepared by dissolving 30 mg of AM salt (ammonium molybdate tetrahydrate, Sigma‐Oldrich, PubChem ID 24896471) in 1 mL of the relevant solvent (DIW, EG, and DIW–EG mixture at the relevant ratios) to form a 3 wt % solution.…”

“…As was discussed before, staining by AM enables to overcome the inherently low contrast of the polymer assemblies and improves their visibility in the cryo‐TEM images.…”

“…The di‐block copolymer poly(O950)‐ b ‐(DEAEMA‐ co ‐BMA) was designed to form micelles under aqueous conditions with the hydrophilic poly(PEGMA) segment forming the micelle corona and the poly(DEAEMA‐ co ‐BMA) segment forming the hydrophobic core . Here, the self‐assembly of the di‐block copolymer, poly (O950)‐ b ‐(DEAEMA‐ co ‐BMA), in EG and EG–DIW mixtures was characterized as a function of polymer concentration using surface tension measurements, DLS and cryo‐TEM.…”

“… Chemical structure and schematic representation of the di‐block copolymer employed in this study . [Color figure can be viewed at http://wileyonlinelibrary.com]…”

“…The combination of the PEGMA block (highly soluble in EG) and the relatively long “solvophobic” tail (the DEAEMA‐ co ‐BMA residue) was expected to favor micellization in EG. This polymer is known to assemble into spherical micelles in aqueous solutions with a low CMC, that depends on the pH of the solutions, as the DEAEMA is a weak (cationic) polybase with a p K a of the conjugated acid of 7.4 …”