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  • Submicron-sized SiO2/Al2O3(Si/Al)-coated titanium dioxide (Si/Al-TiO2) particles were encapsulated through the emulsion copolymerization of methacrylates using a thermoresponsive polymerizable nonionic surfactant, NE-10. An optimized water-dispersion method was developed to disperse Si/Al-TiO2 dried powders using an ultrasonic homogenizer, a paint shaker, and a pot mill rotator in the presence of partially neutralized poly(isobutylene-alt-maleic acid). The encapsulation efficiency (Fen) was affected by the monomer and initiator types, NE-10, and sodium dodecyl sulfonate concentrations. Fen > 90% was achieved by a two-step semibatch emulsion copolymerization under optimized conditions.

    • Md. Kamrul Hasan
    • Kazushi Enomoto
    • Seigou Kawaguchi
    Original Article
  • Three types of aromatic polyketones bearing tetrakis(nonafluorobutyl)-pterphenylene units were successfully synthesized via nucleophilic aromatic substitution polymerization. In particular, high-molecular-weight polymers were obtained in DMAc. These polymers have water and oil repellency, good thermal stability, and excellent solubility in typical organic solvents such as MEK, THF, CHCl3, and DMAc.

    • Haruki Konta
    • Katsuya Maeyama
    Original Article
  • The feasibility of using strongly electron-deficient naphthobispyrazine bisimide (NPI) as a building unit for n-type semiconducting polymers used in all-polymer organic photovoltaics (OPV) cells was investigated. The NPI-based polymers had sufficiently deep LUMO energy levels of ~−3.7 eV and narrow bandgaps of less than 1.5 eV, which matched well energetically with p-type polymers exhibiting wide optical bandgaps. The NPI-based polymers exhibited a clear photoresponse in all-polymer OPV cells blended with PTB7-Th as a benchmark p-type polymer and showed power conversion efficiencies of up to 1.6%.

    • Kenta Okamoto
    • Yuka Iwasaki
    • Itaru Osaka
    Original Article
  • Ring-opening polymerization of a cyclic dithiocarbonate initiated by arylmethyl triflates, derived from benzyl bromide and bis-, tris-, and tetrakis(bromomethyl)benzenes. Synthesis of star-shaped polymers with cores, transferred from initiators and fluorescent dyes (naphthalene, anthracene, perylene) embedded polymers.

    • Chi Gwan Kim
    • Hyo Jo Jeong
    • Jung Yun Do
    Original Article
  • During bulk polymerization, the relative concentration of monomer and polymer changes. When the monomer is liquid and the obtained polymer is a glassy solid, vitrification occurs at some point of the reaction. Herein, we investigate the bulk polymerization of methyl methacrylate, ethyl methacrylate, and butyl methacrylate. We show that, at the vicinity of vitrification, the reaction solution becomes heterogeneous, which results in an apparent phase separation. We discuss polymerization-induced vitrification in conjunction with reaction acceleration (the Trommsdorff effect) and subsequent deceleration (the glass effect).

    • Yasuhito Suzuki
    • Ryutaro Mishima
    • Akikazu Matsumoto
    Original Article
  • A novel substituted phenylacetylene with a pendant betulin derivative group was designed and synthesized successfully, The obtained monomer was further polymerized in an achiral catalytic system, and polymer exhibited a strong Cotton effect at the main-chain absorption regions in the circular dichroism spectra. The helical porous material polyphenylacetylene grafted onto the natural product lupane triterpene as a side group exhibits a set of valuable properties with excellent thermal stability, solubility and membrane-forming ability.

    • Zhichun Shi
    • Jiaxiang Wen
    • Takashi Kaneko
    Original Article
  • PLLA exhibits excellent biocompatibility and biodegradability, but its poor hydrophilicity causes less cell adhesion. To address this issue, the bioactive peptide scaffold was synthesized by PLLA fiber substrate modified with an IKVAV peptide and following heat treatment at 60 °C for regulation of cell adhesive. This scaffold has the potential to serve as an in vitro model for investigating the effect of the ECM on glioblastoma multiforme cells and tumor metastasis in white matter tracts.

    • Wan-Ying Huang
    • Akihisa Otaka
    • Tetsuji Yamaoka
    Original Article
  • Polytetrafluoroethylene (PTFE) has widely been used in essential daily items and biomedical materials. The application range of PTFE should be greatly expanded if it can be flexibly functionalized. However, the functionalization method is still limited. In this study, peptides with affinity to PTFE were identified through affinity-based selection from a phage-displayed peptide library. The peptides had potential as a molecular glue to immobilize functional proteins and biomolecular assemblies, i.e., phages, onto PTFE films.

    • Yuichi Kida
    • Toshiki Sawada
    • Takeshi Serizawa
  • PBDTNTz1 and PBDTNTz2 combining naphtho[1,2-d:5,6-d’]bis([1,2,3]triazole (NTz) and benzo[1,2-b:4,5-b’]dithiophene (BDT) were successfully synthesized as wide-band gap polymers for nonfullerene acceptor polymer solar cells. Bulk heterojunction solar cells with inverted structures using PBDTNTz2:ITIC showed a 2.39% power conversion efficiency. The device utilizing PBDTNTz1:ITIC presented a 7.37% PCE with a high Voc of 0.94 V, an FF of 55.8, and a Jsc of 14.04 mA/cm2. OFETs using PBDTNTz1 and PBDTNTz2 showed hole mobilities of 2.2 × 10−2 cm2V−1s−1 and 5.0 × 10−2 cm2V−1s−1 with current on/off ratios of 1 × 104 and 9 × 102, respectively.

    • Fong-Yi Cao
    • Jhih-Yang Hsu
    • Yen-Ju Cheng
    Original Article
  • The emulsion stabilization conditions suitable for nanocellulose-coated microparticle syntheses was investigated by changing the lengths of nanocelluloses. The optimal nanocellulose concentration for stabilizing the emulsion was found to vary with the nanocellulose length, and longer nanocelluloses efficiently stabilized the emulsion at lower concentrations due to the higher viscosity. The emulsions stabilized by shorter nanocelluloses were found to be more suitable for the preparation of fine microparticles because the nanocelluloses effectively covered the surfaces of oil droplets in the emulsions, precluding coalescence.

    • Shuji Fujisawa
    • Reina Tanaka
    • Tsuguyuki Saito
    Original Article
  • The interdetector delay volumes (IDV) for multiangle light scattering (MALS) and differential refractometer detectors are essential instrumental parameters affecting reliability and accuracy. However, a reliable and accurate determination method has not yet been established. The paper proposes a method for determining the IDV value. An SEC-MALS setup with the correct IDV value provides more accurate estimates of not only the weight average molar mass and z-average mean-square radius of gyration but also the number average molar mass and differential weight distribution function for polymer samples having narrow and broad molar mass distributions.

    • Yoshinori Matsumoto
    • Moriya Kikuchi
    • Seigou Kawaguchi
    Original Article
  • A cholesterol-functionalized poly(3-alkylesterfuran) (P3CHOLEF) was synthesized in three synthetic steps from 2-bromo-3-furoic acid. The polymer is synthesized by Suzuki-Miyaura cross-coupling polymerization using an N-heterocyclic carbene palladium catalyst. P3(CHOL)EF adopts a helical conformation, and the rigid side chain ensures the polymer remains folded in various solvents. This behavior is unique when compared to a similar polymer where the cholesterol group is replaced with S-3-octanol. When P3(CHOL)EF was dissolved in n-octane at room temperature and circularly polarized luminescence behavior was studied, a dissymmetry factor of 0.05 was recorded for the polymer.

    • Manami Kawakami
    • Payton Downey
    • Kevin J. T. Noonan
    Original Article
  • The optimum processing conditions for PEDOT:PSS and PEDOT:PSS/Tween 80 cast films were determined in terms of sheet resistivity and film quality. The sheet resistivity of the films was found to decrease by up 85% following annealing at 140 °C. Further analysis showed this reduction to be created by both moisture removal and structural rearrangement. The presence of Tween 80 significantly altered the thermal stability of PEDOT:PSS films highlighting the importance of reoptimizing processing conditions for each additive used.

    • Joseph L. Carter
    • Catherine A. Kelly
    • Mike J. Jenkins
    Original Article Open Access
  • Double-cyclopolymerization of trifunctional heptaisobutyl-substituted corner-opening typed cage silsesquioxane produced soluble polymers by applying the precision polymerization technique to avoid cross-linking reaction during the polymerization. Cast films of the resulting double cyclic polymers showed excellent optical transparent and good thermal properties as well as stable hydrophobic surfaces.

    • Taishi Nakano
    • Keigo Okamoto
    • Kensuke Naka
    Original Article
  • We develop aldehyde-functionalized conjugated microporous polymer (CMPs) via Pd-catalyzed direct arylation polymerization strategy. The method avoids the pre-fucntionalization and reduces the number of synthetic steps. The polymers exhibit strong visible light absorption (red edge of λabs = ∼605 nm) and solid-state fluorescence (λem = 620 nm; ϕf = ∼5%). The pendant aldehyde functional group in the polymer enables selective fluorescent chemosensing of aliphatic and aromatic amines by enhancing the fluorescence of aliphatic amines and performing fluorescence quenching for aromatic amines.

    • Monika Bai M. G
    • Atul B. Nipate
    • M. Rajeswara Rao
    Original Article
  • In comparison to the ubiquity of their chalcogenic thiophene analogs, selenophene-incorporated conjugated polymers are relatively scarce in the organic electronics literature. However, this scarcity belies the tremendous utility of selenophene in high-performance optoelectronic materials. In this focus review, we discuss the key developments in selenophene-based conjugated polymer research from the early polyselenophene investigations, through the detailed study of regioregular poly(3-hexylselenophene), to the state-of-the-art donor-acceptor polymers that have enabled advancements in the performance and functionality of various optoelectronic devices. Finally, we end with our perspective on the future of this field.

    • Adam V. Marsh
    • Martin Heeney
    Focus Review Open Access
  • The maintenance of stem cells multipotency and control of the differentiation direction are important for these applications in tissue engineering. We explored whether the multipotency of adipose derived stem cells (AdSCs) is maintained when they are removed from injectable polymer (IP) hydrogels with various degrees of cross-linking and induced to differentiate into osteoblasts and adipocytes. We confirmed that AdSCs cultured in IP hydrogels maintained an undifferentiated state. However, when cultured in an IP hydrogel, their multipotency was reduced.

    • Nozomi Mayumi
    • Nobuo Murase
    • Yuichi Ohya
    Original Article Open Access