Flexible or Robust Amorphous Photonic Crystals from Network-Forming Block Copolymers for Sensing Solvent Vapors.

Large-area and flexible amorphous photonic crystals (APCs) featuring interconnected network microstructures are fabricated using high-molecular-weight polystyrene- block-poly(methyl methacrylate) (PS-PMMA) block copolymers. Kinetically controlled microphase separation combining with synergistic weak incompatibility gives rise to short-range-order network microstructures, exhibiting noniridescent optical properties. Solubility-dependent solvatochromism with distinct responses to various organic solvent vapors is observed in the network-forming APC film.

Trapping Structural Coloration by a Bioinspired Gyroid Microstructure in Solid State.

In theory, gyroid photonic crystals in butterfly wings exhibit advanced optical properties as a result of their highly interconnected microstructures. Because of the difficulties in synthesizing artificial gyroid materials having periodicity corresponding to visible wavelengths, human-made visible gyroid photonic crystals are still unachievable by self-assembly. In this study, we develop a physical approach-trapping of structural coloration (TOSC)-through which the visible structural coloration of an expanded gyroid lattice in a solvated state can be preserved in the solid state, thereby allowing the fabrication of visible-wavelength gyroid photonic crystals.

Live Templates of a Supramolecular Block Copolymer for the Synthesis of Ordered Nanostructured TiO Films via Guest Exchange.

In this work, we introduce a facile method based on host-guest chemistry to synthesize a range of nanostructured TiO materials using supramolecular templates of a dendron-jacketed block copolymer (DJBCP). The DJBCP is composed of amphiphilic dendrons (4'-(3,4,5-tridodecyloxybenzoyloxy)benzoic acid, TDB) selectively incorporated into a P4VP block of polystyrene-block-poly(4-vinylpyridine) (PS-b-P4VP) via hydrogen bonding. The PS-b-P4VP host acts as a structure-directing template, while the guest molecules (TDB) assist the self-assembly nanostructures and zone-axis alignment, resulting in the nanostructured template of vertically oriented cylinders formed via successive phase transformations from Im3̅m to R3̅m to P6mm upon thermal annealing in the doctor-blade-cast film.

Simultaneous temperature and magnetization transfer (MT) monitoring during high-intensity focused ultrasound (HIFU) treatment: preliminary investigation on ex vivo porcine muscle.

Purpose: To measure temperature change and magnetization transfer ratio (MTR) simultaneously during high-intensity focused ultrasound (HIFU) treatment.

Materials And Methods: This study proposed an interleaved dual gradient-echo technique to monitor the heat and tissue damage brought to the heated tissue. The technique was applied to tissue samples to test its efficacy.