scholarly journals Gold-Loaded Organic/Inorganic Nanocomposite Honeycomb Membranes

2006 ◽  
Vol 59 (8) ◽  
pp. 539 ◽  
Author(s):  
Kok Hou Wong ◽  
Thomas P. Davis ◽  
Christopher Barner-Kowollik ◽  
Martina H. Stenzel
Keyword(s):  
Block Copolymer ◽  
Block Copolymers ◽  
Raft Polymerization ◽  
Porous Films ◽  
Breath Figures ◽  
Vinyl Pyridine ◽  
Self Assembled ◽  
Gold Nanocomposites ◽  
Hydrolysis Of ◽  
Porous Array

RAFT polymerization was used to prepare polystyrene – poly(4-vinyl pyridine) block copolymers, PSn-b-P(4VP)m. Well-defined block copolymers were obtained despite some indications of hydrolysis of the RAFT endgroup during synthesis. The block copolymer PS70-b-P(4VP)55 was self-assembled into micellar structures in dichloromethane, leading to nanoparticles with hydrodynamic diameters of 70 nm. The micelles were loaded with HAuCl4 and, upon reduction, micellar gold-containing nanoparticles with hydrodynamic diameters of 240 nm were obtained. These nanoparticles were employed in the preparation of honeycomb-structured porous films by means of the breath figures technique to yield gold nanocomposites with a hexagonal porous array.

Solvent Effects on the Synthesis of Polymeric Nanoparticles via Block Copolymer Self-Assembly Using Microporous Membranes

2020 ◽  
Vol 1000 ◽  
pp. 324-330
Author(s):  
Sri Agustina ◽  
Masayoshi Tokuda ◽  
Hideto Minami ◽  
Cyrille Boyer ◽  
Per B. Zetterlund
Keyword(s):  
Block Copolymer ◽  
Block Copolymers ◽  
Self Assembly ◽  
Polymeric Nanoparticles ◽  
Raft Polymerization ◽  
Membrane Emulsification ◽  
Membrane Pore ◽  
Novel Technique ◽  
Wide Range ◽  
Membrane Pore Size

The self-assembly of block copolymers has attracted attention for many decades because it can yield polymeric nanoobjects with a wide range of morphologies. Membrane emulsification is a fairly novel technique for preparation of various types of emulsions, which relies on the dispersed phase passing through a membrane in order to effect droplet formation. In this study, we have prepared polymeric nanoparticles of different morphologies using self-assembly of asymmetric block copolymers in connection with membrane emulsification. Shirasu Porous Glass (SPG) membranes has been employed as the membrane emulsification equipment, and poly (oligoethylene glycol acrylate)-block-poly (styrene) (POEGA-b-PSt) copolymers prepared via RAFT polymerization. It has been found that a number of different morphologies can be achieved using this novel technique, including spheres, rods, and vesicles. Interestingly, the results have shown that the morphology can be controlled not only by adjusting experimental parameters specific to the membrane emulsification step such as membrane pore size and pressure, but also by changing the nature of organic solvent. As such, this method provides a novel route to these interesting nanoobjects, with interesting prospects in terms of exercising morphology control without altering the nature of the block copolymer itself.

Honeycomb-Structured Porous Films from Polypyrrole-Containing Block Copolymers Prepared via RAFT Polymerization as a Scaffold for Cell Growth

2006 ◽  
Vol 7 (4) ◽  
pp. 1072-1082 ◽  
Author(s):  
Danelle Beattie ◽  
Kok Hou Wong ◽  
Charles Williams ◽  
Laura A. Poole-Warren ◽  
Thomas P. Davis ◽  
...  
Keyword(s):  
Cell Growth ◽  
Block Copolymers ◽  
Raft Polymerization ◽  
Porous Films

scholarly journals Antimicrobial Porous Surfaces Prepared by Breath Figures Approach

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1266 ◽  
Author(s):  
Alexandra Muñoz-Bonilla ◽  
Rocío Cuervo-Rodríguez ◽  
Fátima López-Fabal ◽  
José Gómez-Garcés ◽  
Marta Fernández-García
Keyword(s):  
Block Copolymers ◽  
Side Chain ◽  
Porous Films ◽  
Narrow Pore Size Distribution ◽  
Breath Figures ◽  
Gram Positive Bacteria ◽  
Alkyl Groups ◽  
Porous Surfaces ◽  
Cationic Copolymers ◽  
Ordered Porous

Herein, efficient antimicrobial porous surfaces were prepared by breath figures approach from polymer solutions containing low content of block copolymers with high positive charge density. In brief, those block copolymers, which were used as additives, are composed of a polystyrene segment and a large antimicrobial block bearing flexible side chain with 1,3-thiazolium and 1,2,3-triazolium groups, PS54-b-PTTBM-M44, PS54-b-PTTBM-B44, having different alkyl groups, methyl or butyl, respectively. The antimicrobial block copolymers were blended with commercial polystyrene in very low proportions, from 3 to 9 wt %, and solubilized in THF. From these solutions, ordered porous films functionalized with antimicrobial cationic copolymers were fabricated, and the influence of alkylating agent and the amount of copolymer in the blend was investigated. Narrow pore size distribution was obtained for all the samples with pore diameters between 5 and 11 µm. The size of the pore decreased as the hydrophilicity of the system increased; thus, either as the content of copolymer was augmented in the blend or as the copolymers were quaternized with methyl iodide. The resulting porous polystyrene surfaces functionalized with low content of antimicrobial copolymers exhibited remarkable antibacterial efficiencies against Gram positive bacteria Staphylococcus aureus, and Candida parapsilosis fungi as microbial models.

Fluorinated amphiphilic block copolymers via RAFT polymerization and their application as surf-RAFT agent in miniemulsion polymerization

RSC Advances ◽  
2015 ◽  
Vol 5 (20) ◽  
pp. 15461-15468 ◽  
Author(s):  
Bishnu P. Koiry ◽  
Arindam Chakrabarty ◽  
Nikhil K. Singha
Keyword(s):  
Block Copolymer ◽  
Block Copolymers ◽  
Ethylene Glycol ◽  
Raft Polymerization ◽  
Miniemulsion Polymerization ◽  
Amphiphilic Block Copolymers ◽  
Poly Ethylene Glycol ◽  
Raft Agent ◽  
Poly Ethylene ◽  
Glycol Methyl Ether

Preparation of an amphiphilic block copolymer (Am-BCP) based on poly(ethylene glycol) methyl ether methacrylate (PEGMA) and heptafluorobutyl acrylate (HFBA) via RAFT polymerization and application of this Am-BCP as surf-RAFT agent for polymerization of styrene.

Self-Assembled Blends of AB/BAB Block Copolymers Prepared through Dispersion RAFT Polymerization

2016 ◽  
Vol 49 (12) ◽  
pp. 4490-4500 ◽  
Author(s):  
Chengqiang Gao ◽  
Jiaping Wu ◽  
Heng Zhou ◽  
Yaqing Qu ◽  
Baohui Li ◽  
...  
Keyword(s):  
Block Copolymers ◽  
Raft Polymerization ◽  
Self Assembled

Self-Assembly of Block Copolymers for Photonic-Bandgap Materials

MRS Bulletin ◽  
2005 ◽  
Vol 30 (10) ◽  
pp. 721-726 ◽  
Author(s):  
Jongseung Yoon ◽  
Wonmok Lee ◽  
Edwin L. Thomas
Keyword(s):  
Molecular Weight ◽  
Block Copolymer ◽  
Block Copolymers ◽  
Photonic Crystals ◽  
Liquid Crystalline ◽  
Photonic Bandgap ◽  
Photonic Bandgap Materials ◽  
Periodic Microstructures ◽  
Self Assembled ◽  
Bandgap Materials

AbstractSelf-assembled block copolymer systems with an appropriate molecular weight to produce a length scale that will interact with visible light are an alternative platform material for the fabrication of large-area, well-ordered photonic-bandgap structures at visible and near-IR frequencies.Over the past years, one-, two-, and three-dimensional photonic crystals have been demonstrated with various microdomain structures created through microphase separation of block copolymers. The size and shape of periodic microstructures of block copolymers can be readily tuned by molecular weight, relative composition of the copolymer, and blending with homopolymers or plasticizers.The versatility of photonic crystals based on block copolymers is further increased by incorporating inorganic nanoparticles or liquid-crystalline guest molecules (or using a liquid-crystalline block), or by selective etching of one of the microdomains and backfilling with high-refractive-index materials. This article presents an overview of photonic-bandgap materials enabled by self-assembled block copolymers and discusses the morphology and photonic properties of block-copolymer-based photonic crystals containing nanocomposite additives.We also provide a view of the direction of future research, especially toward novel photonic devices.

Honeycomb structured porous films from amphiphilic block copolymers prepared via RAFT polymerization

Polymer ◽  
2007 ◽  
Vol 48 (17) ◽  
pp. 4950-4965 ◽  
Author(s):  
Kok Hou Wong ◽  
Thomas P. Davis ◽  
Christopher Barner-Kowollik ◽  
Martina H. Stenzel
Keyword(s):  
Block Copolymers ◽  
Raft Polymerization ◽  
Amphiphilic Block Copolymers ◽  
Porous Films

scholarly journals Polymer-based multiferroic nanocomposites via directed block copolymer self-assembly

2019 ◽  
Vol 7 (4) ◽  
pp. 968-976 ◽  
Author(s):  
Ivan Terzić ◽  
Niels L. Meereboer ◽  
Harm Hendrik Mellema ◽  
Katja Loos
Keyword(s):  
Magnetic Nanoparticles ◽  
Block Copolymer ◽  
Block Copolymers ◽  
Self Assembly ◽  
Self Assembled

Directed dispersion of magnetic nanoparticles inside self-assembled ferroelectric block copolymers holds promises for future improved multiferroics.

Size effects of self-assembled block copolymer spherical micelles and vesicles on cellular uptake in human colon carcinoma cells

2014 ◽  
Vol 2 (19) ◽  
pp. 2883-2891 ◽  
Author(s):  
Teddy Chang ◽  
Megan S. Lord ◽  
Björn Bergmann ◽  
Alex Macmillan ◽  
Martina H. Stenzel
Keyword(s):  
Block Copolymer ◽  
Size Effects ◽  
Raft Polymerization ◽  
Human Colon ◽  
Carcinoma Cells ◽  
Colon Carcinoma Cells ◽  
Human Colon Carcinoma ◽  
Spherical Micelles ◽  
Self Assembled ◽  
Glycol Methyl Ether

Block copolymers, poly(oligo ethylene glycol methyl ether methacrylate)-block-poly(styrene), POEGMEMA-b-PS, with various block lengths were prepared via RAFT polymerization and subsequently self-assembled into various aggregates to investigate their uptake ability into cancer cells.

A Simple Approach to Micro-Patterned Surfaces by Breath Figures with Internal Structure Using Thermoresponsive Amphiphilic Block Copolymers

2005 ◽  
Vol 58 (8) ◽  
pp. 595 ◽  
Author(s):  
Alexandra Nygard ◽  
Thomas P. Davis ◽  
Christopher Barner-Kowollik ◽  
Martina H. Stenzel
Keyword(s):  
Block Copolymers ◽  
Casting Process ◽  
Amphiphilic Block Copolymers ◽  
Patterned Surfaces ◽  
Stimuli Responsive ◽  
Porous Films ◽  
Breath Figures ◽  
Angle Measurements ◽  
Isopropyl Acrylamide ◽  
Contact Angle Measurements

Employing amphiphilic block copolymers in a casting process to obtain honeycomb-structured films via breath figures leads to a suborder of these porous films. A thermoresponsive block copolymer, polystyrene-block-poly(N-isopropyl acrylamide), was synthesized and used to test the arrangement of both blocks within the honeycomb-structured films. Contact angle measurements reveal that the surface of these films has a different composition compared to the structure of the pores. The pores were found to be enriched in hydrophilic sequences showing stimuli-responsive behavior, whereas the surface reacts like a typical hydrophobic porous film.

Sign in / Sign up

Export Citation Format

Share Document