Articles in 2022

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.

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.

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.

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.

Surface modification of carbon materials with polymers is useful for engineering surface properties and adding functionality to carbon materials. This review article describes processes for coating carbon materials with polybenzimidazoles and their applications.

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.

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.

This review outlines the research across the areas of polymer chemistry and cryobiology We discuss the solutions to problems in cryobiology from the viewpoint of polymeric materials science and the applications of polymer-based cryobiology for biomedical applications. We explain how the recent advances in polymer research have enabled the development of innovative polymeric cryoprotectants with novel mechanisms and the development of state-of-the-art methods for the intracellular delivery of substances, such as drugs, using a cryobiological technique called the freeze-concentration effect.

Recent advances in polymer informatics are reviewed, focusing on experimental research. Data-driven analyses, predictions, and suggestions are becoming more practical, despite the appropriate treatments of higher-order structures and process information acting as bottlenecks. After summarizing recent developments, future challenges in polymer informatics are discussed.

The effect of different types of maleic anhydride-modified polypropylene on interfacial shear strength for carbon fiber-reinforced polypropylene composites: The effect of three types of maleic anhydride-modified polypropylenes (MAPP) on the interfacial shear strength (IFSS) of PP and carbon fiber (CF) were investigated. The localization of MAPP at the interface enabled sufficient chemical interaction regardless of MA content of MAPP, and the differences of MA content had little IFSS dependences. When the chemical interaction is sufficient at the interface, the IFSS values were attributed to the crystallinity at the interphase, which depends on the natures such as crystallinity of MAPP added.

Tricoordinate boron embedded conjugated polymers, so-called p−π* conjugated polymers, have been studied as optoelectronic and sensor materials. p−π* Conjugated polymers usually possess bulky aryl groups that kinetically stabilize the boron centers, and the bulky aryl substituents prohibit intermolecular interactions in the solid state. In this work, we synthesized new p−π* conjugated polymers based on a thiophene-fused thiaborin unit. The thiaborin-based p−π* conjugated polymers exhibited great red shifts in the absorption spectra measured in film state relative to those measured in solution, suggesting strong intermolecular interactions.

Fused expanded pyridinium cation (FEP) was introduced as a side chain of the polymer by click reaction. The obtained polymer offered membranes with good flexibility and showed excellent anion conductivity of 123.4 mS cm^–1 at 80 °C under 80% relative humidity, although ion-exchange capacity of the polymer was quite low (0.77). Remarkable conductivity of the membranes is likely due to the weak interaction between FEP cation and OH^–, which increases the ion mobility and concentration of OH^–.

With recent advancements in the Internet of Things (IoT), indoor organic photovoltaic devices (iOPVs) have attracted increasing attention because of their potential utility as self-sustainable, eco-friendly power sources. This review highlights emerging iOPV technologies based on π-conjugated polymers and oligomeric materials and outlines their fundamental principles and characterization techniques.

Intrinsically stretchable semiconducting polymer materials have been sought for meeting requirements in the development of wearable intelligent electronic devices. In this focus review, our recent progress in main-chain engineering for development of intrinsically stretchable n-type semiconducting materials is described. The topics include four strategies, namely, (i) a conjugation-break spacer approach, (ii) a block copolymer approach, (iii) an all-conjugated statistical terpolymer approach, and (iv) a sequence random copolymer approach, in which specially designed stress-relaxation units or sequences are incorporated along the main chains of naphthalene-diimide-based n-type semiconducting polymers.

The new strategy of two different AS-ODNs (targeting K-ras and YB-1) being delivered simultaneously to the same target cancer cell was investigated using the quantized complex made from AS-ODNs and short β-glucan (schizophyllan (SPG)). We used the quantized complex properties to prepare both end complexes with AS-ODNs on both ends. Both end complexes silenced two target genes and showed high inhibition of cancer cell growth. The results indicate that both end complexes can deliver two antisense sequences at the same time and show a synergistic effect.

Stretchable mechanoelectric generators (MEGs) using ‘π-electrets’ composed of π-conjugated polymers modified with bulky, yet flexible alkyl side chains were fabricated. Facile control of the elastic modulus by blending two miscible alkylated π-conjugated polymers enables the laminated films in a MEG to have high stretching of up to 300%. The fabricated MEGs showed good conformability when applied to a soft object that underwent deformation.

The acidolysis, hydroxypropylation and esterification could influence the DSC curve of TG. Among them, the esterification obviously reduced the initial temperature, peak temperature and conclusion temperature.