Chain propagation/step propagation polymerization. III. An XPS investigation of poly(oxyethylene)‐b‐poly(pivalolactone) telechelomer

Abstract

SynopsisA combination of chain and step propagations is being used to prepare a series of segmented copolymers containing polyoxyethylene and polypivalolactone segments each with narrow molecular weight distributions. The incompatibility of the two segments coupled with the difference in surface energies of the two segments could result in good phase separation with the polyoxyethylene segment thereby being found on the surface. Poly(oxyethy1ene)-co-(pivalolactone) telechelomer, which is the precursor to the segmented copolymer, is used as a model to develop an XPS method for surface analysis. An angular resolution study shows that negligible amounts of poly(pivalo1actone) segments are present near the surface. Core level spectra of the telechelomer and its model compounds are presented to indicate that poly(oxyethy1ene) segment is richer near the surface.

Water-Dispersible Copper Sulfide Nanocrystals via Ligand Exchange of 1-Dodecanethiol

“…71 Both the acetate and oleic acid species will give rise to a C 1s peak originating from carboxylate species (O=C—O – ) at slightly higher binding energies in the range of 288.1–289.1 eV. 71−75 As no peaks are present in this region in the C 1s spectrum of both samples, we conclude that there was no significant amount of acetate or oleic acid present. Moreover, these results show that both types of as-synthesized nanocrystals were capped solely by thiol ligands.…”

Graft copolymers from star‐shaped and hyperbranched polystyrene macromonomers

“…Graft copolymers contain polymer units that are incorporated as side chains onto a backbone polymer chain. The graft moieties can comprise various architectures, such as linear or branched chains,1–9 stars,10 fullerenes,11–13 and, more recently, dendritic units 14–40. The diversity in the structure and nature of graft units, along with that of the backbone, provides access for tailoring the properties of graft copolymers and producing specialty and advanced materials.…”

Carbon nanotubes–polyethylene oxide composite electrolyte for solid-state dye-sensitized solar cells

“…The bare PEO (Fig. 3) shows two resolved C 1s peaks at 284.8 eV and 286.4 eV, corresponding to the vibration of CH 2 (polymer backbone) and C-O-C (ether oxygen connect to two carbon), respectively, as reported in elsewhere [18,19]. According to Kiss et al [20], the C 1s XPS peaks at ∼285 eV and ∼286 eV are assigned to the hydrocarbon-type component (CH 2 ) and the contribution of the ether-type carbon (C-O-C) for PEO molecules.…”