Synthesis of poly(4‐hydroxystyrene)‐based block copolymers containing acid‐sensitive blocks by living anionic polymerization

Living anionic polymerization of an acetal protected 4‐hydroxystyrene monomer, (4‐(2‐tetrahydropyranyloxy)styrene) (OTHPSt), and the chain extension of the poly(OTHPSt) anion with a variety of monomers including styrene, 4‐tert‐butylstyrene, methacryloyl polyhedral oligomeric silsesquioxane (MAPOSS) and hexamethylcyclotrisiloxane is demonstrated. The P(OTHPSt) homopolymer has a glass transition temperature well above room temperature, which facilitates handling and purification of the protected poly(4‐hydroxystyrene) (PHS). The resulting diblock copolymers have narrow dispersities <1.05. Chemoselective mild deprotection conditions for the P(OTHPSt) block were identified to prevent simultaneous degradation of the MAPOSS or dimethylsiloxane (DMS) block, thus allowing for the first reported synthesis of P(HS‐b‐DMS) and P(HS‐b‐MAPOSS). © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 1458–1468     

Lebesgue-Radon-Nikodym theorem with respect to fermionic p-adic invariant measure on ? p

In the paper, we derive an analog of the Lebesgue-Radon-Nikodym theorem with respect to fermionic p-adic invariant measure on ? _p .     

Verification of the 3D dose distribution in spinal radiosurgery by using a BANG3® polymer gel dosimeter

Journal of the Korean Physical Society - In intensity-modulated radiosurgery (IMRS) treatment, radiation delivery techniques require the ability to accurately verify complex three-dimensional (3D)...     

Self-Assembling Catalytic Peptide Nanomaterials Capable of Highly Efficient Peroxidase Activity

The self-assembly of short peptides gives rise to versatile nanomaterials capable of promoting efficient catalysis. We have shown that short, seven-residue peptides bind hemin to produce functional catalytic materials which display highly efficient peroxidation activity, reaching a catalytic efficiency of 3×10⁵ m ⁻¹ s⁻¹. Self-assembly is essential for catalysis as non-assembling controls show no activity. We have also observed peroxidase activity even in the absence of hemin, suggesting the potential to alter redox properties of substrates upon association with the assemblies. These results demonstrate the practical utility of self-assembled peptides in various catalytic applications and further support the evolutionary link between amyloids and modern-day enzymes.     

Synthesis of Indoles from N-Substituted Anilines and Triethanolamine by a Homogeneous Ruthenium Catalyst

N-substituted anilines react with triethanolamine in the presence of a catalytic amount of a homogeneous ruthenium catalyst to give the corresponding 1-substituted indoles in good yields.     

Multiple cation binding by bola-amphiphilic crown ethers: Assessment by fast atom bombardment mass spectrometry

Abstract

Bola-amphiphiles having two aza-18-crown-6 ether rings attached by a covalent spacer (O—O) and an analogous tris (macrocycle) (O—O—O) have been prepared and their cation complexation behavior has been assessed by fast atom bombardment and collisionally activated dissociation tandem mass spectrometry; the key finding is that two cations may simultaneously be complexed by a two- or three-crown system and that this complexation may also involve an anion.     

Liquid crystalline epoxy resin with improved thermal conductivity by intermolecular dipole–dipole interactions

To address tremendous needs for developing efficiently heat dissipating materials with lightweights, a series of liquid crystalline epoxy resins (LCEs) are designed and synthesized as thermally conductive matrix. All prepared LCEs possess epoxies at the molecular side positions and cyanobiphenyl mesogenic end groups. Based on several experimental results such as differential scanning calorimetry, polarized optical microscopy, and X‐ray diffraction, it is found that the LCEs exhibited liquid crystalline mesophases. When LCE is cured with a diamine crosslinker, the cured LCE maintains the oriented LC domain formed in the uncured state, ascribing to a presence of dipole–diploe and π–π interactions between cyanobiphenyl mesogenic end groups. Due to the anisotropic molecular orientation, the cured LCE exhibits a high thermal conductivity of 0.46 W m^?1 K^?1, which is higher than those of commercially available crystalline or amorphous epoxy resins. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, 708–715