Self-Assembly of Coil/Liquid-Crystalline Diblock Copolymers in a Liquid Crystal Solvent

Abstract

The SANS and rheology experiments reported in the main text were also performed on a set of coil/SGLCP diblocks having mesogenic side-groups attached "side-on", with the mesogen's long axis parallel to the polymer backbone ( Figure S1). Side-on and end-on polymers were synthesized from the same set of four PS-PB diblocks and one PB homopolymer using methods described in Reference 36. Side-on polymer properties are summarized in Table S2.All experimental methods for side-on and end-on polymers were identical except the percentage of reacted 1,2-butadiene monomers in side-on polymers was calculated from the relative intensities of peaks at δ = 4.9 ppm (characteristic of vinylic hydrogens in 1,2-butadiene) and δ = 3.6 ppm (characteristic of hydrogens in the side-on mesogen's alkyl tails). Also, rheological temperature ramps on side-on solutions were performed at a rate of 0.5 °C/min, instead of the rate of 1 °C/min used for end-on polymers. TEM experiments were not performed using side-on polymers.

Structure-Property Relations of Liquid Crystalline Gels with ABA-Triblock Copolymers as Gelators

“…A similar trend has been observed for AB-diblock copolymers comprising a PS-block and a functionalized side group liquid crystalline segment. In mixtures with 5CB the microphase separation temperature was influenced by the length of the PS-segments and could be adjusted above or below the T ni [16].…”

“…Later on, Finkelmann et al have shown that the block copolymer segment containing the mesogenic moieties feature a selective solubility in the low molecular weight liquid crystals, whereas the isotropic block is not soluble in the LC solvent [13]. As a result, the flexible segments of an AB-diblock copolymer associate and form a micelle core that is surrounded by a corona of soluble liquid crystalline blocks [14][15][16].…”

“…It has been demonstrated that in such gels the electro-optical response can be influenced by the elastic interaction between the liquid crystalline solvent and the polymer network; hence, they can show faster responses in twisted nematic mode than the respective neat liquid crystals [20]. These gels also have potential as elements in a light scattering electro-optical switching display medium because of the effective formation of LC polydomains resulting in high contrast switching in light scattering mode [16]. The contrast between the scattering intensity with or without an applied electric field as well as the critical voltage was shown to depend on the structure of the gelating network in this type of electro-optical element [21].…”

Theory of liquid crystalline micelles

“…It has been reported coilcoil block copolymers, 1-3 polymeric surfactants, [4][5][6] wormlike micelles, 7,8 and rod-coil block copolymers with rigid blocks. [9][10][11][12][13] The stiff or rigid segments as one of the blocks results in liquid crystalline ordering. [14][15][16][17][18] Diblock copolymers with side-chain liquid crystalline polymers and lyotropic chromonic liquid crystals 19,20 with a plate-like or disk-like central core have also attracted more attention in the recent years.…”

Behaviors of self‐assembled diblock copolymer with pendant photosensitive azobenzene segments

“…From a practical viewpoint, such nanostructures also received considerable attention for fabrication of even smaller feature than those obtained by the photolithography process 7–9. Such nanostructures have potential applications in high‐density data storage media,10, 11 ultrafine filters or membranes,12 as templates for metal nanowires,13, 14 and so forth 15…”