scholarly journals Metallopolymer-block-oligosaccharide for sub-10 nm microphase separation

2020 ◽  
Vol 11 (17) ◽  
pp. 2995-3002 ◽  
Author(s):  
Satoshi Katsuhara ◽  
Hiroaki Mamiya ◽  
Takuya Yamamoto ◽  
Kenji Tajima ◽  
Takuya Isono ◽  
...  
Keyword(s):  
Microphase Separation ◽  
The Novel ◽  
Lamellar Morphology

The novel high-χ BCPs comprising poly(vinyl ferrocene) and oligosaccharides formed hexagonal cylinder morphology with d values of ∼8 nm. Lamellar morphology with d values of ∼9 nm was also realized by mixing these polymers and glucose.

Two interpenetrating monoclinic superlattices of a self-assembling rodcoil copolymer thin film

1994 ◽  
Vol 52 ◽  
pp. 442-443
Author(s):  
L. S. Li ◽  
S. I. Stupp
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Physical Properties ◽  
Microphase Separation ◽  
Film Plane ◽  
Molecular Volume ◽  
Cross Linking ◽  
Self Assembling ◽  
Lamellar Morphology ◽  
Flexible Coil

In earlier work, we showed that the rodcoil copolymer (I), containing a rigid board-like mesogenic block connected to a flexible coil-like diblock of approximately 7 isoprene and 7 styrene units, undergoes a microphase separation in thin films cast from solution. The thin films exhibit a lamellar morphology with a mesogenic core sublayer, a polyisoprene (PI) sublayer and a polystyrene (PS) sublayer alternating along the normal to the layers. If the ratio of the molecular volume of the coil-like chain block to that of the mesogenic block could be increased to a certain value a different morphology of thin films would be expected. After cross-linking among the PI blocks, a molecular object with mesogenic core axes oriented perpendicular to the film plane could be formed which would significantly affect physical properties of thin films. In an attempt to obtain a different micTodomain morphology in thin films a similar rod-coil copolymer with approximately 15 isoprene and 15 styrene units in the coil-like chain block (II) was synthesized in our laboratory.

scholarly journals Hydrogen Bonding-Induced Assembled Structures and Photoresponsive Behavior of Azobenzene Molecule/Polyethylene Glycol Complexes

Polymers ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1360 ◽  
Author(s):  
Tai ◽  
Lin ◽  
Ma ◽  
Lo
Keyword(s):  
Hydrogen Bonding ◽  
Polyethylene Glycol ◽  
Microphase Separation ◽  
Domain Size ◽  
Hydrogen Bonding Interaction ◽  
Hydrogen Bonding Interactions ◽  
Lamellar Morphology ◽  
Bonding Interaction ◽  
And Inversion ◽  
High Polarity

We investigated the self-assembled structures and photoresponsive and crystallization behaviors of supramolecules composed of 4-methoxy-4′-hydroxyazobenzene (Azo) molecules and polyethylene glycol (PEG) that were formed through hydrogen-bonding interactions. The Azo/PEG complexes exhibited the characteristics of photoresponse and crystallization, which originated from Azo and PEG, respectively. When Azo/PEG complexes were dissolved in solvents, hydrogen-bonding interaction hindered the rotation and inversion of mesogens, causing a reduction in the photoisomerization rate compared with the photoisomerization rate of the neat Azo. The confinement of Azo/PEG complexes in thin films further resulted in a substantial decrease in the photoisomerization rate but an increase in the amounts of H-aggregated and J-aggregated mesogens. Regarding PEG crystallization, ultraviolet irradiation of Azo/PEG complexes increased the quantity of high-polarity cis isomers, which improved the compatibility between mesogens and PEG, subsequently increasing the crystallization temperature of PEG. Moreover, the complexation of Azo and PEG induced microphase separation, forming a lamellar morphology. Within the Azo-rich microphases, mesogens aggregated to form tilted monosmectic layers. By contrast, PEG crystallization within the PEG-rich microphases was hard confined, indicating that the domain size of the lamellar morphology was unchanged during PEG crystallization.

Synthesis and Nanophase-Separated Morphology of a Diblock Copolymer of Polypentafluorostyrene-b-Poly(methyl methacrylate) by Atom Transfer Radical Polymerization

2007 ◽  
Vol 124-126 ◽  
pp. 595-598
Author(s):  
Yoon Soo Ko ◽  
Yong Ku Kwon
Keyword(s):  
Methyl Methacrylate ◽  
Atom Transfer Radical Polymerization ◽  
Radical Polymerization ◽  
Diblock Copolymer ◽  
Chemical Structure ◽  
Microphase Separation ◽  
Atom Transfer ◽  
Poly Methyl Methacrylate ◽  
Dsc Measurements ◽  
Lamellar Morphology

We synthesized a symmetric, fluorine-containing diblock copolymer of polypentafluorostyrene-b-poly(methyl methacrylate) (PPFS-b-PMMA) by atom transfer radical polymerization (ATRP). The PPFS macroinitiator was also synthesized by ATRP by using 1-phenylethyl bromide initiator. The chemical structure of the polymer was confirmed by GPC, 1H-NMR and DSC measurements. Due to the chemical dissimilarity between the PPFS and PMMA blocks, the microphase-separation was occurred during annealing at high temperature, displaying a lamellar morphology with a thickness of approximately 35 nm.

scholarly journals Investigations into Morphology and Mechanical Properties of Epoxidized Polystyrene/Polybutadiene/Polystyrene (SBS) Triblock Copolymer

2013 ◽  
Vol 28 ◽  
pp. 42-47 ◽  
Author(s):  
Rajesh Pandit ◽  
Boulos Youssef ◽  
Jean Marc Saiter ◽  
Rameshwar Adhikari
Keyword(s):  
Mechanical Properties ◽  
Tensile Testing ◽  
Triblock Copolymer ◽  
Microphase Separation ◽  
Chemical Society ◽  
Performic Acid ◽  
Scanning Calorimetry ◽  
Lamellar Morphology ◽  
Morphology And Mechanical Properties

An architecturally asymmetric polystyrene-block-polybutadiene-block-polystyrene (SBS) triblock copolymer possessing lamellar morphology was subjected to different degrees of epoxidation with performic acid generated in situ by the reaction between hydrogen peroxide and formic acid. The effect of the chemical modification on morphology and mechanical behaviour of the block copolymer was investigated by means of different techniques such as electron microscopy, Fourier transform Infrared (FTIR) spectroscopy, tensile testing and differential scanning calorimetry (DSC). It was found that the microphase separation behaviour and hence the mechanical properties of the materials can be drastically altered via epoxidation of the diene block of the styrene/diene triblock copolymers. DOI: http://dx.doi.org/10.3126/jncs.v28i0.8057 Journal of Nepal Chemical Society Vol.28, 2011 Page 42-47 Uploaded date: May 7, 2013

Morphological studies of linear (AB)n multiblock copolymers and their blends

1992 ◽  
Vol 50 (1) ◽  
pp. 384-385
Author(s):  
Richard J. Spontak ◽  
Steven D. Smith ◽  
Arman Ashraf
Keyword(s):  
Electron Microscopy ◽  
Microphase Separation ◽  
Multiblock Copolymers ◽  
First Order ◽  
Morphological Studies ◽  
Transmission Electron ◽  
First Order Phase Transition ◽  
Covalently Bonded ◽  
Total Molecular Weight ◽  
First Order Phase

Block copolymers are composed of sequences of dissimilar chemical moieties covalently bonded together. If the block lengths of each component are sufficiently long and the blocks are thermodynamically incompatible, these materials are capable of undergoing microphase separation, a weak first-order phase transition which results in the formation of an ordered microstructural network. Most efforts designed to elucidate the phase and configurational behavior in these copolymers have focused on the simple AB and ABA designs. Few studies have thus far targeted the perfectly-alternating multiblock (AB)n architecture. In this work, two series of neat (AB)n copolymers have been synthesized from styrene and isoprene monomers at a composition of 50 wt% polystyrene (PS). In Set I, the total molecular weight is held constant while the number of AB block pairs (n) is increased from one to four (which results in shorter blocks). Set II consists of materials in which the block lengths are held constant and n is varied again from one to four (which results in longer chains). Transmission electron microscopy (TEM) has been employed here to investigate the morphologies and phase behavior of these materials and their blends.

The novel steroidal glycoside from the dried bulb of Allium Macrostemon Bunge inhibits platelet activation

2010 ◽  
Vol 34 (8) ◽  
pp. S33-S33
Author(s):  
Wenchao Ou ◽  
Haifeng Chen ◽  
Yun Zhong ◽  
Benrong Liu ◽  
Keji Chen
Keyword(s):  
Platelet Activation ◽  
The Novel ◽  
Steroidal Glycoside ◽  
Allium Macrostemon

The novel histamine H2 receptor antagonist FRG-8813 prevents delay of wound repair induced by hydrogen peroxide in a rabbit gastric epithelial cell system

1998 ◽  
Vol 13 (11-s4) ◽  
pp. S209-S213
Author(s):  
NOBUHIRO SATO ◽  
SUMIO WATANABE ◽  
XIAN-EN WANG ◽  
TARO OSADA ◽  
HIROSHI TANAKA ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Epithelial Cell ◽  
Receptor Antagonist ◽  
Wound Repair ◽  
Cell System ◽  
The Novel ◽  
H2 Receptor Antagonist ◽  
Histamine H2 Receptor ◽  
H2 Receptor ◽  
Histamine H2 Receptor Antagonist

1444: Functional Effect of the Novel Rho-Kinase Inhibitor H-1152 in the Erectile Machinery

2004 ◽  
Vol 171 (4S) ◽  
pp. 380-380
Author(s):  
Cleber E. Teixeira ◽  
R. Clinton Webb
Keyword(s):  
Kinase Inhibitor ◽  
Rho Kinase ◽  
The Novel ◽  
Functional Effect ◽  
Rho Kinase Inhibitor

From the idyll to the novel: Karamzin's Sentimentalist prose

1991 ◽  
Author(s):  
Gitta Hammarberg
Keyword(s):  
The Novel
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