Fluorene Based Conjugated Polyelectrolyte/Silica Nanocomposites: Charge‐Mediated Phase Aggregation at the Organic–Inorganic Interface

Abstract

Polyfluorene based conjugated polyelectrolyte/silica nanocomposites are fabricated using sol‐gel processing. Ionic termination groups on the conjugated polyelectrolyte lateral chains are shown to control the interaction at the inorganic‐organic interface, leading to macroscale homogeneity and nanophase separation in a single material. The extent of nanophase separation is determined by the nature of the ionic groups, which may provide a means of controlling donor‐acceptor distances in hybrid systems.

Selective Fluorescence Quenching in Cationic Fluorene‐Thiophene Diblock Copolymers for Ratiometric Sensing of Anions

“…There are indications that these interactions may be accompanied by aggregation. Aggregation in conjugated polyelectrolytes has recently been reviewed,44 and can be minimized both by use of co‐solvent or surfactant44 and/or incorporation of the fluorophore in appropriate matrices 45…”

Targeted design leads to tunable photoluminescence from perylene dicarboxdiimide–poly(oxyalkylene)/siloxane hybrids for luminescent solar concentrators

“…14 For host-guest systems, where the lumophore is physically trapped in the matrix (so-called Class I hybrids), cooperative interactions (e.g. hydrogen bonding, ionic, van der Waals, p-p stacking) at the interface play a crucial role in determining phase miscibility [15][16][17] and the orientation of individual components. [18][19][20] However, with suitable chemical functionalisation of the p-conjugated molecule, for example through the addition of reactive alkoxysilane groups, they can be covalently-grafted to a silica framework, forming a Class II organic-inorganic hybrid.…”

Harnessing self-assembly strategies for the rational design of conjugated polymer based materials

“…for solid-state sensors and displays, whilst simultaneously providing an alternative route to exert control over polymer conformation and orientation, 11,77,78 as well as improving environmental stability. 78,79 Moreover, weak physical interactions can also be exploited and coordinated to yield desirable morphologies at the organic-inorganic interface. 79 The preparation of CP-organic-inorganic hybrids is nontrivial.…”

“…Moreover, in the absence of specic interactions between the two components, aggregation of the organic constituent in the inorganic matrix oen occurs during the solgel process, leading to macroscale phase separation. A number of methods have been proposed to address these difficulties, which include (i) the use of water-soluble CPEs; 79 (ii) introducing a zwitterionic mediator; 80 (iii) the use of polar aprotic solvents; 78,81,82 and (iv) co-templating with non-ionic surfactants. 77,78,[81][82][83] We will now consider each approach in turn.…”

“…Evans and co-workers have shown that the charge on the CPE chains can critically affect the extent of phase aggregation at the organic-inorganic interface in poly(uorene)-silica hybrids. 79 Silica nanocomposites prepared from the anionic poly[9,9-bis(4-sulfonylbutoxyphenyl)uorene-2,7-diyl-alt-1,4-phenylene] (PBS-PFP) and cationic PFP-NR3 are homogeneously mixed at the micron scale, but simultaneously exhibit nanoscale separation at the phase interface. Solid-state 29 Si magic-angle spinning (MAS) NMR, AFM and PL measurements indicated that immiscibility at the nanoscale is more pronounced for the cationic PFP-NR3, which is attributed to a more homogenous uptake of the anionic PBS-PFP into the condensing silica network, mediated by hydrogen bonding interactions between terminal SO 3 À units on the CPE and silanol groups.…”