Oligomeric ionmer-grafted silica nanoparticles were synthesized via atom transfer radical polymerization (ATRP) and applied to dope Nafion to investigate proton-sweeping effect of these hybrid nanoparticles. Two types of vinyl monomers, sulfopropyl acrylate, potassium (SPA) and N,N’-methyl-(6-hexylcarbamatoethylmethacrylate) imidazolonium bromide (EMACI), were employed to construct the grafted ionmer chains. The ionmer-grafted silica particles present a thick polymer layer surrounding the SiO2 core according to TEM investigation. The DSC analysis shows that the grafted ionmer oligomers (DP < 10) exhibit a stronger ionic attractive interaction than the corresponding long chain counterparts. The other structural characterizations of the ionmer-grafted SiO2 nanoparticles also include FT-IR and EDX. The most interesting feature of the grafted ionmer shrub lies in its proton-conduction enhancing effect when combined with Nafion® polymer. A series of such composite membranes were prepared through dispersing the ionmer-grafted SiO2 nanoparticles in Nafion solution and followed by casting. The grafted copolymer (SPA-co-EMACI) demonstrated a greater promoting effect on proton conduction than its homopolymer counterparts of either (SPA) or (EMACI) in the matrix of Nafion. This outcome could be attributed to the adjacent proton-sweeping effect of the pendant imidazolonium group.

In this research, the ability of a series of novel oligomeric organic species to control crystal nucleation and growth of inorganic crystals was investigated. The issues under consideration were (i) the relative balance of hydrophobicity and hydrophilicity which might be programmed into a polymer; (ii) the impact metal binding, or bridging on its activity in a crystallization reaction; (iii) the mode of self organisation. An homologous series of alkyl substituted sulphonated calixarenes were used to probe these issues.The ability of a metal cation to either bridge adjacent calix[4]arenes or to adsorb into the molecular cavity had an impact upon the interaction of these molecules with the nascent crystals; selective and specific adsorption behaviours were revealed by the expression of smooth well defined new faces in the equilibrium morphology of the crystals. When the hydrophobicity index was high (increased molecular weight of alkyl substituent) these compounds segregated at the gas/liquid interface and, as a consequence of cation-induced ordering, were able to induce the oriented nucleation of crystals. When the metal ion was preferentially adsorbed into the molecular cavity the complex induced twinning in the crystal form. These studies have revealed that, in contrast to earlier studies which argued for the only for an epitaxial relationship between the polymer and crystal, a tunable range of several chemical characteristics can be programmed into a polymeric substrates if they are to be used to control nucleation and growth.

Single-stranded DNA wraps helically around individual single walled carbon nanotubes to form a DNA/CNT hybrid, which is both stable and dispersible in aqueous solution. Subjected to ion-exchange chromatography, a hybrid elutes at an ionic strength that depends on the electronic band structure of the core nanotube, thus providing a mechanism for separating nanotubes by chirality. We present experimental data and a theoretical model for this separation process on dielectric substrates that explains all the salient features observed experimentally to date, and provides accurate predictions for critical elution salt concentration. The competition between adsorption on the stationary phase and counterion condensation in the mobile phase is characterized by estimating the difference in free energy between the two states of the hybrid. Parametric study of the DNA wrapping geometry, SWNT dielectric properties, hybrid length and diameter indicates that the elution is most sensitive to the hybrid's effective charge density, primarily governed by the DNA helical pitch. The model correctly predicts hybrids with metallic nanotubes are weaker binding than hybrids with semiconducting nanotubes and larger diameter nanotubes are eluted at later times.