Publishing type：Research paper (scientific journal)   Publisher：Royal Society of Chemistry ({RSC})  

Porous nanoparticles with interfacial adhesiveness boost the selectivity of separation membranes to achieve size-selective nanofiltration.

DOI： 10.1039/D1TA06205K

Publishing type：Research paper (scientific journal)   Publisher：MDPI AG  

Polymer-stabilised blue phase (PSBP) could be employed in novel fast response optical and photonic devices. It is inferred that inside PSBPs, the polymers are selectively aggregated by location in −1/2 disclinations, which are defects coexisting with the blue phase as a periodic lattice, thereby extending the temperature range of the blue phase. The polymer aggregate structure in PSBPs strongly affects their physical properties. In this study, we employed a non-destructive synchrotron ultra-small-angle X-ray diffraction analysis to investigate the effect of polymerisation rates on the polymer aggregate structure in PSBPs prepared with monomers of different polymerisation rates and examined the structure formation process of the polymer during polymerisation. When methacrylate monomers, which exhibit a relatively low polymerisation rate, were used to form polymers in PSBP, the resulting polymer was more selectively aggregated at disclinations in the PSBP. Furthermore, the electro-optical effect in the PSBP was successfully improved by reducing the polymer concentration in the PSBPs prepared with the optimised monomer combinations.

DOI： 10.3390/sym13050772

Authorship：Lead author   Publishing type：Research paper (scientific journal)   Publisher：Wiley  

DOI： 10.1002/ange.201901308

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：CHEMICAL SOC JAPAN  

An octahedral metal-organic framework (MOF), UiO-68, with two hydroxymethyl groups (UiO68-hyd) was synthesized for the first time and the hydroxy groups were post-synthetically modified with iso(thio)cyanates to form (thio)urethanes. Several organotins and tertiary amines were used as catalysts for the modification of UiO68-hyd with butyl isocyanate (BuNCO), and 70% of hydroxy groups reacted after 7 days. Moreover, various isocyanate and isothiocyanate compounds were successfully modified on UiO68-hyd.

DOI： 10.1246/cl.180955

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Royal Society of Chemistry  

Self-organized structures of biomolecular motor systems, such as cilia and flagella, play key roles in the dynamic processes of living organisms, like locomotion or the transportation of materials. Although fabrication of such self-organized structures from reconstructed biomolecular motor systems has attracted much attention in recent years, a systematic construction methodology is still lacking. In this work, through a bottom-up approach, we fabricated artificial cilia from a reconstructed biomolecular motor system, microtubule/kinesin. The artificial cilia exhibited a beating motion upon the consumption, by the kinesins, of the chemical energy obtained from the hydrolysis of adenosine triphosphate (ATP). Several design parameters, such as the length of the microtubules, the density of the kinesins along the microtubules, the depletion force among the microtubules, etc., have been identified, which permit tuning of the beating frequency of the artificial cilia. The beating frequency of the artificial cilia increases upon increasing the length of the microtubules, but declines for the much longer microtubules. A high density of the kinesins along the microtubules is favorable for the beating motion of the cilia. The depletion force induced bundling of the microtubules accelerated the beating motion of the artificial cilia and increased the beating frequency. This work helps understand the role of self-assembled structures of the biomolecular motor systems in the dynamics of living organisms and is expected to expedite the development of artificial nanomachines, in which the biomolecular motors may serve as actuators.

DOI： 10.1039/c7nr05099b

Language：English   Publishing type：Research paper (scientific journal)   Publisher：NATURE PUBLISHING GROUP  

The artificial construction of anisotropic deforming materials is one of the great challenges in materials and polymer chemistry. In this paper, we demonstrate a unidirectionally deformable material with reversibility. First, crystal crosslinking of a pillared-layer metal-organic framework (PLMOF) was accomplished, followed by the exchange of the pillar ligand with the monotopic ligand. The obtained crosslinked MOF crystal showed reversible unidirectional compression and expansion during cycles of drying and immersion in good solvents. The macroscopic unidirectional deformation was derived from microscopic variations in the layer distance in the MOF crystal. The polymerization between the organic ligand and the crosslinker effectively reinforced the MOF crystal, which had enough durability for reversible unidirectional deformation. Our strategy is a promising general method for the construction of anisotropic deforming materials, which are often seen in biological systems and mechanical devices.

DOI： 10.1038/pj.2017.32

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Magnetic ferrites are stable, sustainable, and economical. Consequently, they have been used in various fields. The development of large coercive field (large H-c) magnetic ferrites is a very important but challenging issue to accelerate the spread of use and to expand practical applications. In this study, we prepared a rhodium-substituted epsilon-iron oxide film and observed a remarkably large H-c value of 35 kOe at room temperature. This is the largest value among magnetic ferrites to date. Such a large H-c ferrite is expected to greatly expand the application of magnetic ferrites. Furthermore, when the temperature dependence of the magnetic properties was measured, an even larger H-c value of 45 kOe was recorded at 200 K. Such large H-c values are much larger than those of conventional hard magnetic ferrites.

DOI： 10.1021/jacs.7b07087

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOC CHEMISTRY  

The preparation of the polymers having a self-attractive urea unit via hydrogen bonding and a selfrepulsive lipophilic ion unit via electrostatic interaction was carried out to achieve the thermoresponsivity of polymer solution. The solubility of the obtained copolymers depended on the balance between the attractive force induced by hydrogen bonding among the urea units and the repulsive force attributed to the dissociation of the ionic units. In aprotic and nonpolar solvents, the solubility of the polymers was changed from insoluble to soluble with the increasing content of the ionic units. Moreover, in acetonitrile and 1,2-dichloroethane, the UCST-type thermoresponsivity was observed. This result indicated that the UCST-type thermoresponsivity was induced by cleavage of the hydrogen bonds among urea units upon heating, and at the cloud point, the repulsive force among the ionic units overwhelmed the attractive force. From the result of this research, we would like to emphasize that the combination of a lipophilic ion pair and other self-attractive units can be a simple principle for the molecular design of UCST-type thermoresponsive polymers in any media.

DOI： 10.1039/c7py00591a

Language：English   Publishing type：Research paper (scientific journal)   Publisher：CHEMICAL SOC JAPAN  

We have demonstrated in vitro motility assay of microtubules on a kinesin-coated substrate by using adenosine triphosphate (ATP) generated from microsphere gels containing thylakoid membranes. Upon photoirradiation, the gels generated ATP, which was utilized for performing gliding motions of microtubules. This work may facilitate the development of a localized ATP generation system in the in vitro motility assay, which consequently would widen the applications of biomolecular motors in nanotechnology.

DOI： 10.1246/cl.160903

Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

Metal-organic frameworks (MOFs) are well-ordered microporous crystalline materials synthesized from metal cluster nodes and organic ligands. Using organic ligands with functional and reactive moieties enables post-synthetic modification (PSM) for further functionalization of MOFs. In this study, bioconjugation of MOFs with functional motor proteins, such as kinesin microtubule (MT) system was investigated by employing PSM. Kinesin-MT system, energy diffusive gliding motion of MT was performed by consuming chemical energy of adenosine-triphosphate (ATP) in vitro. Thus, we attempted establishment of gliding of MOF by applying bio-motor system, in which reconstituted MT filaments are propelled over a kinesin-coated substrate in the presence of ATP.

DOI： 10.1002/slct.201601431

Language：English   Publishing type：Research paper (scientific journal)   Publisher：NATURE PUBLISHING GROUP  

Ferrite magnets have a long history. They are used in motors, magnetic fluids, drug delivery systems, etc. Herein we report a mesoscopic ferrite bar magnet based on rod-shaped epsilon-Fe2O3 with a large coercive field (>25 kOe). The epsilon-Fe2O3-based bar magnet is a single crystal with a single magnetic domain along the longitudinal direction. A wide frequency range spectroscopic study shows that the crystallographic alpha-axis of epsilon-Fe2O3, which corresponds to the longitudinal direction of the bar magnet, plays an important role in linear and non-linear magneto-optical transitions, phonon modes, and the magnon (Kittel mode). Due to its multiferroic property, a magnetic-responsive non-linear optical sheet is manufactured as an application using an epsilon-Fe2O3-based bar magnet, resin, and polyethylene terephthalate. Furthermore, from the viewpoint of the large coercive field property, we demonstrate that a mesoscopic epsilon-Fe2O3 bar magnet can be used as a magnetic force microscopy probe.

DOI： 10.1038/srep27212