Polymer/dye blends: Preparation and optical performance: A short review

Abstract

This review focuses on the optimization of the optical performance of polymer/dye blends in which dyes are physically dispersed in polymer matrices. The optimization of the optical performance of polymer/dye blends is discussed in terms of: (i) the preparation procedure of polymer/dye blends (melt processing is considered particularly effective for producing polymer/dye blends with optimal dye distribution); (ii) mechanical and thermal solicitations after polymer/dye blend preparation; (iii) the polymer matrix, whose affinity for the dye and crystallinity affects the optical performance the polymer/dye blend; and (iv) the dye, whose chemical structure and concentration are significant determinants of the optical properties of polymer/dye blends.

Effect of Polymer Host on Aggregation-Induced Enhanced Emission of Fluorescent Optical Brighteners

“…Six commercially available optical brighteners with conjugated π-systems were chosen for initial screening: 1,4-bis­(benzo­[ d ]­oxazol-2-yl)­naphthalene (BBON), 4,4′-bis­(2-benzoxazolyl) stilbene (BBS), 4,4-bis­(2-methoxystyryl)­biphenyl (BMSB), 2,5-bis­[5-( tert -butyl)-1,3-benzoxazol-2-yl]­thiophene (BTBBT), bis­(5-methyl-2-benzoxazolyl)­ethylene (BMBE), and 4-(2-benzoxazolyl)-4′-(5-methyl-2-benzoxazolyl)­stilbene (BMBS) (Figure ). The presence of aryl groups along the dye core (1) provides easily excitable electrons for fluorescence transitions and (2) limits the mobility of the dyes, preventing dispersion and promoting aggregation . Three concentrations (low0.1 wt %, med0.5 wt %, and high1 wt % with respect to polymer matrix) of each optical brightener were melt blended with HDPE to test for AIEE behavior.…”

“…In systems with tunable crystallinities, the relative dye concentration and aggregation probability can be altered. , PLA and PET are polymer systems that display crystallinity flexibility. Their crystallinities can be modulated from low values (∼5%) up to moderate crystallinities (ca.…”

“…In systems with an increased number of guest–host interactions, the threshold concentration for aggregation is reduced as intermolecular interactions take precedence over dye–dye aggregation-inducing interactions. , For example, the aggregation threshold of Disperse Red 1 (DR1) changes drastically when dissolved in matrices with increasing polarity: polystyrene (PS), poly­(4-vinyl-phenol) (PVPh), or poly­(styrene-sulfonic acid) (PSSA) . An increased number of guest–host intermolecular interactions due to hydrogen bonds forming between the –OH present in PVPh and DR1, or the formation of an ionic complex between DR1 and the sulfonic acid group of PSSA, maximizes chromophore separation and results in an increased aggregation threshold. − …”

Poly(dimethylsiloxane) as a room-temperature solid solvent for photophysics and photochemistry

“…[41][42][43][44][45] Modifying the dyes with functional groups of the monomers allows them to covalently attach to the polymer chains during the polymerization and/or crosslinking processes. 46,47 Mixing chromophores with a prepolymer and a curing agent offers a means for doping PDMS with coloured and fluorogenic agents. [48][49][50][51] For the fidelity of such methods, however, the polymerization and curing crosslinking chemistry must not interfere with the doping species.…”

“…Adding dyes to molten thermoplastic polymers or their room-temperature solutions in volatile organic solvents and spin-coating or casting them result in solid films with chromophores incorporated in them. 47,52,53 The impossibility of melting thermoset polymers or dissolving them in organic solvents precludes the extension of this doping approach to them. Nevertheless, while PDMS is thermoset, it is a porous material.…”