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Organic lyotropic liquid‐crystal (LLC) assemblies mimic molecular sieves in their nanoporous structures and their ability to incorporate catalytic functional groups. This article focuses on recent advances made by our research group in incorporating new catalytic properties into polymerizable LLC assemblies and studying the molecular‐transport properties of the crosslinked networks.

The catalytic reactivity and selectivity of the first example of a nanostructured solid acid resin (1) are described. This new type of solid acid catalyst is formed by the self-assembly and copolymerization of two acidic lyotropic liquid crystals (LLCs), affording a columnar hexagonal polymer network with monodisperse nanochannels lined with sulfonic acid groups. The performance of this material as a heterogeneous catalyst was compared against that of two commercially available, amorphous sulfonic acid resins: Amberlyst-15 and Nafion NR50. Using the acid-catalyzed esterification of benzyl alcohol with 1-hexanoic acid in dry toluene as a test reaction, it was found that resin 1 displayed only slightly lower overall reactivity as compared to Amberlyst-15 and Nafion NR50 but more than an order of magnitude higher selectivity for the desired ester product over dibenzyl ether side-product. Control experiments revealed that the higher product selectivity is not due to differences in relative acidity between the nanostructured acid resin and the two amorphous resins. Instead, it appears that a large component of the enhanced selectivity is due to the regular nanostructure present in the LLC resin, which affords a much more uniform local acid microenvironment for reactions to occur. Resin 1 can also be recycled with almost complete recovery of catalytic activity and selectivity, and with essentially no leaching of reactive groups into the solution phase.

Streptococcus mutans has been reported as a primary cariogenic pathogen associated with dental caries. The bacteria can produce glucosyltransferases (Gtfs) to synthesize extracellular polysaccharides (EPSs) that are known as virulence factors for adherence and formation of biofilms. Therefore, an ideal inhibitor for dental caries is one that can inhibit planktonic bacteria growth and prevent biofilm formation. Bergenia crassifolia (L.), widely used as a folk medicine and tea beverage, has been reported to have a variety of bioactivities. The present study aimed to explore the effect of B. crassifolia (L.) leaf extracts on the biofilm of Streptococcus mutans. The B. crassifolia (L.) leaf extracts showed inhibitory effects by decreasing viability of bacteria within the biofilm, as evidenced by the XTT assay, live/dead staining assay and LDH activity assay, and could decrease the adherence property of S. mutans through inhibiting Gtfs to synthesize EPSs. In addition, the reduced quantity of EPSs and the inhibition of Gtfs were positively correlated with concentrations of test samples. Finally, the MTT assay showed that the extracts had no cytotoxicity against normal oral cells. In conclusion, the extracts and sub-extracts of B. crassifolia leaves were found to be antimicrobial and could reduce EPS synthesis by inhibiting activities of Gtfs to prevent bacterial adhesion and biofilm formation. Therefore, B. crassifolia leaves have potential to be developed as a drug to prevent and cure dental caries.

Several taper-shaped, Brønsted acidic amphiphiles containing an amide linkage near the headgroup were synthesized with the goal of generating acidic, inverted hexagonal (HII) lyotropic liquid crystal (LLC) phases that can be stabilized by polymerization. These polymerizable acidic amphiphiles were synthesized by reacting the acyl chloride of 3,4,5-tris(11‘-acryloxyundecyloxy)benzoic acid with several amino acids (l-alanine, β-alanine, l-phenylalanine) and 2-aminoethanesulfonic acid. Of these derivatives, only the l-alanine derivative (1) was found to form the HII phase, using N,N-dimethylformamide as the hydrophilic solvent. To our knowledge, this is one of the rare examples (if not the only example) of a Brønsted acidic amphiphile capable of forming a high-curvature LLC phase. Monomer 1 was also found to be able to direct the formation of the other amide-containing acidic derivatives into the HII phase when blended together. IR analysis revealed that intermolecular amide H-bonding near the headgroup plays a major role in the LLC assembly and structure-directing behavior of these systems.