Highly Ordered Structure Formation in RAFT-Synthesized PtBOS-b-P4VP Diblock Copolymers.

Macromol Rapid Commun

Department of Polymer Chemistry, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747, AG, Groningen, The Netherlands.

Published: June 2016

Linear poly(4-tert-butoxystyrene)-b-poly(4-vinylpyridine) (PtBOS-b-P4VP) diblock copolymers are synthesized using reversible addition-fragmentation chain transfer polymerization. The self-assembly of four different PtBOS-b-P4VP diblock copolymers is studied using small-angle X-ray scattering and transmission electron microscopy and a number of interesting observations are made. A tBOS62 -b-4VP28 diblock copolymer with a weight fraction P4VP of 0.21 shows a disordered morphology of P4VP spheres with liquid-like short-range order despite an estimated value of χN of the order of 50. Increasing the length of the 4VP block to tBOS62 -b-4VP199 results in a diblock copolymer with a weight fraction P4VP of 0.66. It forms a remarkably well-ordered lamellar structure. Likewise, a tBOS146 -b-4VP120 diblock copolymer with a weight fraction P4VP of 0.33 forms an extremely well-ordered hexagonal structure of P4VP cylinders. Increasing the P4VP block of this block copolymer to tBOS146 -b-4VP190 with a weight fraction P4VP of 0.44 results in a bicontinuous gyroid morphology despite the estimated strong segregation of χN≅150. These results are discussed in terms of the architectural dissimilarity of the two monomers, characterized by the presence of the large side group of PtBOS, and the previously reported value of the interaction parameter, χ≅0.39, for this polymer pair.

Download full-text PDF

Source
http://dx.doi.org/10.1002/marc.201600052DOI Listing

Publication Analysis

Top Keywords

weight fraction
16
fraction p4vp
16
ptbos-b-p4vp diblock
12
diblock copolymers
12
diblock copolymer
12
copolymer weight
12
despite estimated
8
p4vp
7
diblock
6
highly ordered
4

Similar Publications

Aging in a weighted ensemble of excitable and self-oscillatory neurons: The role of pairwise and higher-order interactions.

Chaos

January 2025

International Research Center for Neurointelligence, The University of Tokyo Institutes for Advanced Study, The University of Tokyo, Bunkyo Ku, Tokyo 113 8654, Japan.

We investigate the aging transition in networks of excitable and self-oscillatory units as the fraction of inherently excitable units increases. Two network topologies are considered: a scale-free network with weighted pairwise interactions and a two-dimensional simplicial complex with weighted scale-free pairwise and triadic interactions. Without triadic interactions, the aging transition from collective oscillations to oscillation death (inhomogeneous stationary states) can occur either suddenly or through an intermediate state of partial oscillation.

View Article and Find Full Text PDF

Basic Science and Pathogenesis.

Alzheimers Dement

December 2024

Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.

Background: In Alzheimer's disease (AD), the spread of Tau proteopathic seeds across the cerebral cortex parallels the disease progression. Previously, it was shown that isolating high-molecular-weight (HMW) Tau species via size exclusion chromatography (SEC) from human brain lysate of AD patients resulted in the enrichment of Tau aggregation-prone species. However, whether the HMW Tau population contain a homogenous or heterogeneous mixture of Tau species is still unknown.

View Article and Find Full Text PDF

Basic Science and Pathogenesis.

Alzheimers Dement

December 2024

Department of Anatomy, Cell Biology, and Physiology, Indiana University School of Medicine, Indianapolis, IN, USA.

Background: Tau aggregates, a hallmark of Alzheimer's disease (AD) and other tauopathies, spread throughout the brain, contributing to neurodegeneration. How this propagation occurs remains elusive. Previous research suggests that tau-seed interactors play a crucial role.

View Article and Find Full Text PDF

Background And Purpose: The aim was to estimate the cost of the external beam radiotherapy (EBRT) in public health care centers in Catalonia (Spain), according to the ESTRO-HERO costing model for 2018.

Materials And Methods: Personnel, equipment, and activity data from 2018 from the 11 RT centers were used, incorporating European mean values adapted to the Catalan context. Secondly, EBRT costs were estimated, incorporating 2023 fractionation technique and scheme usage percentages.

View Article and Find Full Text PDF

Introduction: Elevated central aortic pressure, cardiac output and peripheral vascular resistance contribute to high morbidity in relation to end organ dysfunction in obstructive and non-obstructive coronary artery disease (NOCAD) cases despite revascularization. Bisoprolol preempts further progression of left ventricular dysfunction in such cases due to anti-ischemic and anti-hypertensive effects, further extending its evaluation in local Indian settings.

Methods: Post-hoc analyses of NOCAD patients with epicardial stenosis (N=378, 30 to 70% stenosis) from cross-sectional analyses conducted across eighty centers in India.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!