Supramolecular modification of sustainable high-molar-mass polymers for improved processing and performance.

The plastic waste crisis is among humanity's most urgent challenges. However, widespread adoption of sustainable plastics is hindered by their often inadequate processing characteristics and performance. Here, we introduce a bio-inspired strategy for the modification of a representative high molar mass, biodegradable aliphatic polyester that helps overcome these limitations and remains effective at molar masses far greater than the entanglement molar mass.

Poly(benzodifurandione) Coated Silk Yarn for Thermoelectric Textiles.

Thermoelectric textile devices represent an intriguing avenue for powering wearable electronics. The lack of air-stable n-type polymers has, until now, prevented the development of n-type multifilament yarns, which are needed for textile manufacturing. Here, the thermomechanical properties of the recently reported n-type polymer poly(benzodifurandione) (PBFDO) are explored and its suitability as a yarn coating material is assessed.

Impact of doping on the mechanical properties of conjugated polymers.

Conjugated polymers exhibit a unique portfolio of electrical and electrochemical behavior, which - paired with the mechanical properties that are typical for macromolecules - make them intriguing candidates for a wide range of application areas from wearable electronics to bioelectronics. However, the degree of oxidation or reduction of the polymer can strongly impact the mechanical response and thus must be considered when designing flexible or stretchable devices. This tutorial review first explores how the chain architecture, processing as well as the resulting nano- and microstructure impact the rheological and mechanical properties.

Fine wettability control created by a photochemical combination method for inkjet printing on self-assembled monolayers.

Wettability tuning for organic solvents is demonstrated with the "combination method", a reversal of the conventional "cleavage method". Several advantages are inherent to this method: for example, the syntheses are simple, various surface-active groups can be used, and the reaction proceeds with a low-energy light source. The image shows the result after UV irradiation through a patterning mask.

What kind of "soft materials" can we design from molecular gels?

Since their discovery, over the years, molecular gels have been constantly drawing the attention of chemists from various scientific fields. Their structural softness together with the orderliness at the molecular level provides such molecules immense potential for the amplification of their properties. Using this chemistry, one can easily realize a macroscopic outcome from a molecular level modulation.

Transcription of chirality in the organogel systems dictates the enantiodifferentiating photodimerization of substituted anthracene.

An organogelator (G) that contains 2-anthracenecarboxylic acid (2Ac) attached covalently to a gelator counterpart that consists of 3,4,5-tris(n-dodecan-1-yloxy)benzoic acid by means of a chiral amino alcohol linkage has been synthesized. G acts as an efficient gelator of organic solvents, including mixed solvents and chiral solvents. Photodimers isolated after the photoreaction of the gel samples display different degrees of stereoselectivity.

Studies on a new class of organogelator containing 2-anthracenecarboxylic acid: influence of gelator and solvent on stereochemistry of the photodimers.

A new class of binary organogelator (G1, G2 and G3) based on 2-anthracenecarboxylic acid (2Ac), attached noncovalently with the gelator counterpart containing a 3,4,5-tris(n-dodecyloxy)benzoylamide backbone has been developed. Among the three gelators, two (G2 and G3) are chiral containing D-alanine or L-2-phenylglycine moieties, respectively. They can act as efficient gelators of organic solvents with varying polarity depending upon the gelator systems.

Control of polythiophene redox potentials based on supramolecular complexation with helical schizophyllan.

A novel method to control polythiophene redox potentials based on supramolecular complexation with the native polysaccharide, schizophyllan (SPG) is reported, which can importantly improve air stability for easy handling and processing.

On the helical motif of the complexes created by association of helix-forming schizophyllan (SPG) and helix-forming polythiophene derivatives.

pi-Conjugated polymers can finely tune their electrical and optical properties in response to their conformational changes. We believe that a deeper understanding of their higher-order structures will stimulate further development of their applications. We had revealed that one helix-forming natural polysaccharide (SPG) and one polythiophene derivative (PT-1) formed a stable one-dimensional complex and in the polythiophene main chain a helical conformation was induced through the dynamic conformational changes.

Quantum dots arrangement and energy transfer control via charge-transfer complex achieved on poly(phenylene ethynylene)/schizophyllan nanowires.

Assemblies of organic and inorganic compounds in the nanoscale region have contributed to the development of novel functional materials toward future applications, including sensors and opto-electronics. We succeed in fabricating hybrid nanowires composed of a conjugated polymer and semiconductor quantum dots (QDs) by a supramolecular assembly technique. The 1-D fashion of the nanowire structure is obtained by the polymer wrapping of cationic poly(phenylene ethynylene) (PPE) with helix-forming polysaccharide schizophyllan (SPG).

An organogel system can control the stereochemical course of anthracene photodimerization.

A novel photoresponsive organogel with a binary gelator containing 2-anthracenecarboxylic acid shows a high degree of stereochemical control, resulting in head-to-head photocyclodimers exclusively together with significant enantiomeric excess induced by the chiral counterpart of the gelator.

Creation of polynucleotide-assisted molecular assemblies in organic solvents: general strategy toward the creation of artificial DNA-like nanoarchitectures.

The influence of added polynucleotide on the gelation ability of nucleobase-appended organogelators was investigated. Uracil-appended cholesterol gelator formed a stable organogel in polar organic solvents such as n-butanol. It was found that the addition of the complementary polyadenylic acid (poly(A)) not only stabilizes the gel but also creates the helical structure in the original gel phase.

Controlled stability of the triple-stranded helical structure of a beta-1,3-glucan with a chromophoric aromatic moiety at a peripheral position.

We synthesized a semiartificial beta-1,3-glucan, curdlan with dialkylaniline groups (CUR-DA), that bears chromophoric aromatic groups at its peripheral positions. Spectroscopic studies as well as microscopic observations indicate that CUR-DA adopts a triple-stranded helical structure in water- or methanol-rich solutions of dimethyl sulfoxide (DMSO). This triple-stranded helical structure exhibits high thermal stability and resistance to base, attributes that are similar to those of the triple-stranded helical structure of native beta-1,3-glucans such as schizophyllan.

Beta-1,3-glucan polysaccharide (schizophyllan) acting as a one-dimensional host for creating supramolecular dye assemblies.

We have demonstrated that one-dimensional supramolecular dye assemblies with a uniform diameter can be created by utilizing schizophyllan (SPG) as a one-dimensional host. In the supramolecular nanofibers, the dye molecules are assembled into the different aggregation modes depending on the preparation procedures. The findings establish that SPG is useful for creating the supramolecular nanofibers, where temporal superstructures can be stabilized by the SPG-specific helical higher-order structure.

Poly(diacetylene)-nanofibers can be fabricated through photo-irradiation using natural polysaccharide schizophyllan as a one-dimensional mold.

Schizophyllan interacts with various 1,4-diphenylbutadiyne derivatives to induce their chirally-twisted packing. A series of referential experiments using other polysaccharides (amylose, pullulan, dextran, etc.) and a carbohydrate-appended detergent (dodecyl-beta-d-glucopyranoside) indicates that these 1,4-diphenylbutadiyne derivatives are accommodated within a tubular cavity constructed by a helical superstructure of schizophyllan.

Oligosilane-nanofibers can be prepared through fabrication of permethyldecasilane within a helical superstructure of schizophyllan.

[chemical structure: see text]. Schizophyllan can interact with permethyldecasilane to produce the corresponding decasilane-nanofiber, in which the decasilane adopts helical conformations in a tubular hollow created by the helical superstructure of schizophyllan.

'Click chemistry' on polysaccharides: a convenient, general, and monitorable approach to develop (1-->3)-beta-D-glucans with various functional appendages.

(1-->3)-beta-D-Glucans having various functional appendages (lactoside, ferrocene, pyrene, and porphyrin) can be prepared in an convenient, quantitative, and regioselective manner through regioselective bromination-azidation of curdlan to afford 6-azido-6-deoxycurdlan followed by chemoselective [3+2]-cycloadditions with various functional modules bearing a terminal alkyne group. The ability to monitor reaction conversions is an additional advantage of this synthetic approach over the conventional direct modifications on polysaccharides; the reaction can be readily monitored based on the intensity of azido peaks in the in situ attenuated total reflection infrared spectra.

Schizophyllan-folate conjugate as a new non-cytotoxic and cancer-targeted antisense carrier.

Schizophyllan having folate-appendages was synthesized from native schizophyllan through NaIO(4)-oxidation and the subsequent reductive amination in aqueous ammonia followed by amido-coupling with folic acid. The resulting folate-appended schizophyllan can form stable complex with poly(dA), show specific affinity toward folate binding protein, and mediate effective antisense activity in cancer cells.