scholarly journals Can percolation theory explain the gelation behavior of diblock copolymer worms?

2018 ◽  
Vol 9 (35) ◽  
pp. 7138-7144 ◽  
Author(s):  
Joseph R. Lovett ◽  
Matthew J. Derry ◽  
Pengcheng Yang ◽  
Fiona L. Hatton ◽  
Nicholas J. Warren ◽  
...  
Keyword(s):  
Block Copolymer ◽  
Diblock Copolymer ◽  
Percolation Theory ◽  
Gelation Behavior ◽  
Physical Gelation

Physical gelation by block copolymer worms can be explained in terms of multiple inter-worm contacts using percolation theory, suggesting that worm entanglements are irrelevant in this context.

scholarly journals Rational synthesis of novel biocompatible thermoresponsive block copolymer worm gels

Soft Matter ◽  
2021 ◽  
Author(s):  
Deborah L. Beattie ◽  
Oleksandr O. Mykhaylyk ◽  
Anthony J. Ryan ◽  
Steven P. Armes
Keyword(s):  
Block Copolymer ◽  
Diblock Copolymer ◽  
Degree Of Polymerization ◽  
Amphiphilic Diblock Copolymer ◽  
Gelation Behavior ◽  
The Mean

Judicious control over the mean degree of polymerization of each block in a amphiphilic diblock copolymer ensures that the corresponding worm gel exhibits thermoreversible (de)gelation behavior, as judged by TEM, SAXS and rheology studies.

scholarly journals Block copolymer microparticles comprising inverse bicontinuous phases prepared via polymerization-induced self-assembly

2019 ◽  
Vol 10 (15) ◽  
pp. 4200-4208 ◽  
Author(s):  
Pengcheng Yang ◽  
Yin Ning ◽  
Thomas J. Neal ◽  
Elizabeth R. Jones ◽  
Bryony R. Parker ◽  
...  
Keyword(s):  
Block Copolymer ◽  
Internal Structure ◽  
Diblock Copolymer ◽  
Self Assembly ◽  
Bicontinuous Phases

Scalable preparation of micrometer-sized diblock copolymer particles exhibiting complex internal structure is achieved by RAFT-mediated polymerization-induced self-assembly (PISA).

Phase Transitions in Thin Block Copolymer Films

MRS Bulletin ◽  
2010 ◽  
Vol 35 (6) ◽  
pp. 457-465 ◽  
Author(s):  
Edward J. Kramer
Keyword(s):  
Phase Transition ◽  
Phase Transitions ◽  
Block Copolymer ◽  
Diblock Copolymer ◽  
Smectic Liquid Crystals ◽  
Material System ◽  
Thermal Generation ◽  
Copolymer Films ◽  
Bcc Structure ◽  
Line Defects

AbstractDavid Turnbull's experiments and theoretical insights paved the way for much of our modern understanding of phase transitions in materials. In recognition of his contributions, this lecture will concentrate on phase transitions in a material system not considered by Turnbull, thin diblock copolymer films. Well-ordered block copolymer films are attracting increasing interest as we attempt to extend photolithography to smaller dimensions. In the case of diblock copolymer spheres, an ordered monolayer is hexagonal, but the ordered bulk is body-centered cubic (bcc). There is no hexagonal plane in the bcc structure, so a phase transition must occur as n, the number of layers of spheres in the film, increases. How this phase transition occurs with nand how it can be manipulated is the subject of the first part of my presentation. In the second part of the talk, I show that monolayers of diblock copolymer spheres and cylinders undergo order-to-disorder transitions that differ greatly from those of the bulk. These ordered 2D monolayers are susceptible to phonon-generated disorder as well as to thermal generation of defects, such as dislocations, which, while they are line defects in 3D, are point defects in 2D. The results are compared to the theories of melting of 2D crystals (spheres) and of 2D smectic liquid crystals (cylinders), a comparison that will allow us to understand most, but not all, of the features of these order-disorder transitions that occur as the temperature is increased.

Synthesis of Self-Assembled Metal-Oxide Nanostructures in a Diblock Copolymer Matrix and Integration onto Semiconductor Surfaces

2000 ◽  
Vol 642 ◽  
Author(s):  
Robert F. Mulligan ◽  
Agis A. Iliadis ◽  
U. Lee ◽  
Peter Kofinas
Keyword(s):  
Block Copolymer ◽  
Diblock Copolymer ◽  
Photoelectron Spectroscopy ◽  
Ring Opening ◽  
Diblock Copolymers ◽  
X Ray ◽  
Oxide Nanostructures ◽  
Metal Oxide Nanostructures ◽  
Self Assembled ◽  
Zno Nanoclusters

ABSTRACTThe synthesis of self-assembled ZnO nanostructures at room temperature using a microphase separated diblock copolymer as a template is reported. Poly(norbornene) / poly(norbornene-dicarboxylic acid) diblock copolymers were synthesized using Ring Opening Metathesis Polymerization (ROMP). The polymers were dissolved and the solutions were doped with ZnCl2. Films were formed from this solution, and subsequently reacted with NH4OH. This converted the ZnCl2 into ZnO contained within the microphase-separated nanodomains of the block copolymer. Fourier Transform Infrared Spectroscopy verified the association of the metal to the second block of the polymer, and X-ray Photoelectron Spectroscopy verified the conversion of the salt to ZnO nanoclusters. The development of such ZnO - block copolymer nanocomposites is targeting the functionalization of nanostructures into device technologies.

Electric-field-induced lamellar to hexagonally perforated lamellar transition in diblock copolymer thin films: kinetic pathways

2016 ◽  
Vol 18 (36) ◽  
pp. 25609-25620 ◽  
Author(s):  
Arnab Mukherjee ◽  
Kumar Ankit ◽  
Andreas Reiter ◽  
Michael Selzer ◽  
Britta Nestler
Keyword(s):  
Thin Films ◽  
Block Copolymer ◽  
Electric Field ◽  
Diblock Copolymer ◽  
Substrate Interaction ◽  
Symmetric Block

In this work, the confluence of an electric field, substrate interaction and confinement is shown to induce a parallel lamellar to hexagonally perforated lamellar transition in symmetric block-copolymer thin films.

pH-responsive microspheres encapsulated with iron oxide nanoaggregates for gastrointestinal delivery

2012 ◽  
Vol 27 (1) ◽  
pp. 54-66 ◽  
Author(s):  
Young Ju Son ◽  
Hyuk Sang Yoo
Keyword(s):  
Iron Oxide ◽  
Block Copolymer ◽  
Block Copolymers ◽  
Diblock Copolymer ◽  
Ph Responsive ◽  
Polymeric Microspheres ◽  
Intestinal Delivery ◽  
Poly Ethylene ◽  
The Stability

Block copolymer-stabilized iron oxide nanoaggregates were fabricated into pH-responsive polymeric microspheres for intestinal delivery of the magnetic nanoaggregates. A diblock copolymer consisted of methoxy poly(ethylene glycol) (mPEG) and poly(e-caprolactone) (PCL) was synthesized by ring-opening polymerization. Microspheres, consisted of Eudragit L100-55 encapsulate and stabilized magnetic nanoaggregates, were prepared by an oil-in-oil emulsification technique. The magnetization of the microspheres decreased, and the stability of the magnetic nanoaggregates in aqueous solutions increased as the amount of block copolymers in the microspheres increased. The encapsulated magnetic nanoaggregates were visualized by scanning electron microscopy and energy-dispersive X-ray spectroscopy. The encapsulation efficiency of nanoaggregates of the microspheres increased as the amount of diblock copolymer in the nanoaggregates was increased. The in vitro experiments confirmed the pH-dependent release of the nanoaggregates from the microspheres. The microspheres were administered to the animals by oral gavages, and the nanoaggregates in small intestines were visualized by histological examination of intestinal inner walls. Higher amounts of the block copolymer in the nanoaggregates increased the uptake efficiency in the intestinal tissues. Thus, the incorporation of the block copolymers in the magnetic nanoaggregates increased the intestinal absorption of the aggregates and Eudragit microspheres and effectively protected the nanoaggregates at low pH conditions of the stomach area.

Symmetric Diblock Copolymer Thin Films on Rough Substrates. Kinetics and Structure Formation in Pure Block Copolymer Thin Films

2005 ◽  
Vol 38 (5) ◽  
pp. 1837-1849 ◽  
Author(s):  
E. Sivaniah ◽  
Y. Hayashi ◽  
S. Matsubara ◽  
S. Kiyono ◽  
T. Hashimoto ◽  
...  
Keyword(s):  
Thin Films ◽  
Block Copolymer ◽  
Structure Formation ◽  
Diblock Copolymer ◽  
Pure Block

scholarly journals All-aqueous continuous-flow RAFT dispersion polymerisation for efficient preparation of diblock copolymer spheres, worms and vesicles

2019 ◽  
Vol 4 (5) ◽  
pp. 852-861 ◽  
Author(s):  
Sam Parkinson ◽  
Nicole S. Hondow ◽  
John S. Conteh ◽  
Richard A. Bourne ◽  
Nicholas J. Warren
Keyword(s):  
Block Copolymer ◽  
Diblock Copolymer ◽  
Continuous Flow ◽  
Dispersion Polymerization ◽  
Aqueous Dispersion

A continuous-flow platform enables rapid kinetic profiling and accelerated production of block copolymer nano-objects via RAFT aqueous dispersion polymerization.

Synthesis of polymeric nano-objects of various morphologies based on block copolymer self-assembly using microporous membranes

2017 ◽  
Vol 2 (4) ◽  
pp. 451-457 ◽  
Author(s):  
Sri Agustina ◽  
Masayoshi Tokuda ◽  
Hideto Minami ◽  
Cyrille Boyer ◽  
Per B. Zetterlund
Keyword(s):  
Block Copolymer ◽  
Diblock Copolymer ◽  
Self Assembly ◽  
Microporous Membranes ◽  
Novel Approach

Polymeric nano-objects of a range of morphologies have been prepared using a novel approach based on the use of microporous membranes for mixing of a solvent (containing a diblock copolymer) and a non-solvent.

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