9H-carbazole-9-ethyl and 9H-carbazole-9-hexyl-terminated polyhedral octasilicate (OS)-core dendrimers, denoted as OS-C2-Cz and OS-C6-Cz, respectively, were prepared by ring-opening reaction and subsequent condensation of octakis(propenyl succinicanhydrido)polyhedral octasilicate (OS-SA) with 9H-carbazole-9-ethanol (Cz-C2-OH) and 9H-carbazole-9-hexanol (Cz-C6-OH), respectively. Both the dendrimers formed optical transparent coating films. In particular, the coating film of OS-C2-Cz was easily peeled off from a substrate and formed a free-standing film. The results of X-ray diffraction and differential scanning calorimeter suggest that the films of OS-C2-Cz and OS-C6-Cz were amorphous. Thermogravimetric analysis of OS-C2-Cz and OS-C6-Cz showed 10 wt % weight losses at 374 and 383 °C, respectively. Photoluminescence property revealed that the carbazole group in OS-C2-Cz is prevented the excimer formation, while the carbazole group in OS-C6-Cz formed the excimer. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 628–633

Organic–inorganic hybrid multilayer films were prepared on a precoated cationic glass substrate by using a layer-by-layer (LbL) electrostatic self-assembly technique with poly(diallyldimethylammonium chloride) as a polycation and submicron-sized stable amorphous calcium carbonate (ACC) composite particles. The ACC composite particles (ACP) stabilized with poly(acrylic acid) were obtained by a carbonate controlled-addition method. The average particles size of ACP was (1.8 ± 0.4) × 10² nm. An ethanolic dispersion of ACP was used for the LbL electrostatic self-assembly technique on the precoated substrate due to instability of ACP in water. The deposition of the particles was confirmed by SEM analysis. The film thickness of the multilayer assembly increased from 230 to 710 nm with increasing the deposition layers. The FTIR spectra of scratched multilayer samples showed characteristic broaden peaks of ACC. The amorphous phase was stable after the LbL assembly process as well as after 2 months in a dry film state. POLYM. COMPOS., 36:330–335, 2015. © 2014 Society of Plastics Engineers

Liquid-crystalline (LC) hydrogels were obtained from an aqueous solution of poly(p-phenylene-sulfoterephthalamide) (PPST) by the addition of calcium ions (Ca²⁺). The critical hydrogel formation ratio of Ca²⁺ to the sulfonic acid group in PPST (^crtR_Ca = [Ca²⁺]/[ ]) depended on the concentration of PPST, and was independent of the molecular weight of PPST. When the LC hydrogel was prepared at a concentration of 0.5 wt % and ^crtR_Ca = 0.6, and was exposed to ammonium carbonate vapor for 96 h, all Ca²⁺ in the LC hydrogel were converted into calcite crystals. The alternate soaking process for the LC hydrogel induced the formation of two mesocrystal morphologies on and in the Ca²⁺ cross-linked LC hydrogel. Plate-like calcite mesocrystals grew at the hydrogel/solution interface and cubic mesocrystals were present in the inner space of the hydrogel, thus composites with some ordered structures of LC matrix and CaCO₃ have been prepared through in situ mineralization. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41455.

2-Biphenylethyl and 2-biphenylhexyl-terminated polyhedral oligomeric octasilicate (OS)-core polyester-typed dendrimers, denoted as OS-C2-BP and OS-C6-BP, respectively, were prepared by ring-opening reaction and subsequent condensation of octakis(propenyl succinicanhydrido)polyhedral octasilicate (OS-SA) with 2-(4-phenylphenoxy)ethanol (BP-C2-OH) and 6-(4-phenylphenoxy)hexanol (BP-C6-OH), respectively. OS-C2-BP formed a transparent film, whereas OS-C6-BP formed an opaque whitish waxy film. The coating film of OS-C2-BP was easily peeled off from a substrate and formed a free-standing film. The results of X-ray diffraction and differential scanning calorimeter suggest that the film of OS-C2-BP was amorphous, whereas OS-C6-BP contained crystalline domains. Thermogravimetric analysis of OS-C2-BP and OS-C6-BP showed 5 wt % weight losses at 362 °C and 283 °C, respectively. OS-C2-BP offered higher thermal resistance than OS-C6-BP. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 1437–1443

A mechanochromic luminescent dye based on a simple aminomaleimide skeleton was readily synthesized in a one-pot process. It exhibited an on/off mechanochromic luminescent switching property dependent on external stimuli, unlike a traditional mechanochromic color change. The green emission was turned on by grinding in a mortar and turned off by heating or treatment with dichloromethane. In the crystalline state, two molecules were stacked by cofacial π–π interactions, which caused concentration self-quenching. The crystalline-to-amorphous transition induced by grinding removed cofacial π–π stacking, which led to intensive emission. Crystallizing processes recovered the cofacial π–π stacking, resulting in elimination of the emission. Theoretical calculations and X-ray diffraction analyses revealed that the dye molecule was distorted in the crystalline state; thus even a mechanical stimulus caused the crystalline-to-amorphous transition.

Aggregation-induced emission (AIE)-active maleimide dyes, namely, 2-p-toluidino-N-p-tolylmaleimide, 3-phenyl-2-toluidino-N-p-tolylmaleimide, 2-p-thiocresyl-3-p-toluidino-N-p-tolylmaleimide, and 2,3-dithiocresyl-N-arylmaleimides, were synthesized by facile synthetic procedures. The dyes show intense emission in the solid state, and emission colors were controlled from green (λ_max=527 nm) to orange (λ_max=609 nm) by varying the substituents at the 2- and 3-positions of the maleimide and the packing structures in the solid state. 2,3-Disubstituted maleimide dyes effectively underwent redshifts of their emission wavelength. Furthermore, some of the dyes exhibited mechanochromism and polymorphism, and their emission properties were dramatically dependent on the morphology of the solid samples. The mechanisms of the emission behaviors were investigated by X-ray diffraction. The substituent of the nitrogen atom of the maleimide ring affected the intermolecular interactions and short contacts, which were observed by single crystal X-ray crystallography, to result in completely different emission properties.

An imidazole-terminated hyperbranched polymer with octafunctional POSS branching units denoted as POSS-HYPAM-Im was prepared by the polymerization of excess amounts of tris(2-aminoethyl)amine with the first-generation methyl ester-terminated POSS-core poly(amidoamine)-typed dendrimer, reacting with methyl acrylate, and ester-amide exchange reaction with 3-aminopropylimidazole. The imidazole-terminated hyperbranched poly(amidoamine) denoted as HYPAM-Im was also synthesized with 1-(3-aminopropyl)imidazole from a methyl ester-terminated hyperbranched poly(amidoamine) by the ester-amide exchange reaction. The transmittance of the POSS-HYPAM-Im solution drastically decreased when the solution pH was greater than 8.2. On the other hand, the transmittance of the HYPAM-Im solution gradually decreased when the solution pH at 8.5 and was greater than 9. Spectrophotometric titrations of the hyperbranched polymer aqueous solutions with Cu²⁺ ions indicated the variation of the coordination modes of POSS-HYPAM-Im from the Cu²⁺–N₄ complex to the Cu²⁺–N₂O₂ complex and the existence of the only one complexation mode of Cu²⁺–N₄ between Cu²⁺ ion and HYPAM-Im with increasing the concentrations. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 2695–2701

Dumbbell-shaped isobutyl-substituted 1,2-bis(4-vinylphenyl)acetylene-linked POSS (DA1), 9,10-bis(4-vinylphenyl)ethynyl)anthracene-linked POSS (DA2), and 5,5″-bis((4-vinyl)phenyl)ethynyl)-2,2′:5′2″-terthiophene-linked POSS (DA3), and corresponding model compounds were synthesized by cross metathesis and Sonogashira reaction, and their film formability, and thermal and optical properties were examined. The dumbbell structures of the obtained compounds were confirmed by ¹H-, ¹³C-, and ²⁹Si-NMR and MALDI-TOF-MS analysis. The dumbbell-shaped POSS compounds gave optically transparent films. All the model compounds, however, formed opaque films. All the films were emissive under UV irradiation. The dumbbell structures minimize longer wavelength shifts and improve emission efficiency of the luminescent π-conjugated linker units in their solid states compared with the model compounds. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012.