Radio-opaque Micelles for X-ray Imaging

2014 ◽  
Vol 67 (1) ◽  
pp. 78 ◽  
Author(s):  
Zhiyong Wang ◽  
Teddy Chang ◽  
Luke Hunter ◽  
Andrew M. Gregory ◽  
Marcel Tanudji ◽  
...  
Keyword(s):  
Block Copolymers ◽  
Self Assembly ◽  
Block Size ◽  
Drug Carriers ◽  
Block Copolymerization ◽  
X Ray ◽  
Transmission Electron ◽  
X Ray Imaging ◽  
Reversible Addition ◽  
Rate Of Polymerization

Block copolymers based on iodinated monomers were prepared with the aim of creating nanoparticles as contrast agents suitable for X-ray imaging. Reversible addition–fragmentation chain-transfer polymerization was employed to synthesize block copolymers based on oligo(ethylene glycol) methylether methacrylate (OEGMEMA) and 2-[2′,3′,5′-triiodobenzoyl]oxyethyl methacrylate (METB). The polymerization of METB was found to be slow owing to the low solubility of the monomer, which does not allow high enough concentration to achieve a fast rate of polymerization. However, the block copolymerization was well controlled, resulting in several block copolymers, POEGMEMA-b-PMETB, which were further investigated in regards to their self-assembly in water. Micelles were prepared using POEGMEMA55-b-PMETB18, POEGMEMA55-b-PMETB32, POEGMEMA100-b-PMETB22, and POEGMEMA100-b-PMETB32. Transmission electron microscopy and dynamic light scattering revealed micelle sizes between 30 and 45 nm depending on the block size. The micelles were found to show a strong contrast similar to BaSO4 and Visipaque (iodixanol) during X-ray analysis. These micelles can now further be employed as drug carriers or can be conjugated to a bioactive group for targeting.

Synthesis of Polystyrene-B-Poly(Ethylene Oxide)monomethyl Ethermethacrylate Block Copolymers and its Self-Assembly in Aqueous Solution

2011 ◽  
Vol 284-286 ◽  
pp. 769-772
Author(s):  
Qian Qian You ◽  
Pu Yu Zhang
Keyword(s):  
Aqueous Solution ◽  
Molecular Weight ◽  
Block Copolymers ◽  
Self Assembly ◽  
Chain Transfer ◽  
Functional Group ◽  
Transmission Electron ◽  
Reversible Addition ◽  
Ft Ir ◽  
A Chain

The block copolymer of PSt-b-POEOMA with the end of -COOH functional group has been synthesized by reversible addition fragmentation chain-transfer (RAFT) using S,S′-Bis(α,α′-dimethyl-α′′-acetic acid)-trithiocarbonate (BDATC) as a chain transfer agent. The architectures of the copolymers were confirmed by FT-IR and 1HNMR spectra. GPC analysis was used to estimate the molecular weight and the molecular weight distribution of the copolymers. Meanwhile, The nanostructures of the block copolymers PSt-b-POEOMA micelles formed in aqueous solution were observed by transmission electron microscopy (TEM) and dynamic light scattering (DLS).

scholarly journals Synthesis of Terpyridine-Terminated Amphiphilic Block Copolymers and Their Self-Assembly into Metallo-Polymer Nanovesicles

Materials ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 601 ◽  
Author(s):  
Tatyana Elkin ◽  
Stacy Copp ◽  
Ryan Hamblin ◽  
Jennifer Martinez ◽  
Gabriel Montaño ◽  
...  
Keyword(s):  
Polyethylene Glycol ◽  
Block Copolymers ◽  
Self Assembly ◽  
Chain Transfer ◽  
Raft Polymerization ◽  
Amphiphilic Block Copolymers ◽  
Transmission Electron ◽  
Reversible Addition ◽  
Efficient Route ◽  
High Yields

Polystyrene-b-polyethylene glycol (PS-b-PEG) amphiphilic block copolymers featuring a terminal tridentate N,N,N-ligand (terpyridine) were synthesized for the first time through an efficient route. In this approach, telechelic chain-end modified polystyrenes were produced via reversible addition-fragmentation chain-transfer (RAFT) polymerization by using terpyridine trithiocarbonate as the chain-transfer agent, after which the hydrophilic polyethylene glycol (PEG) block was incorporated into the hydrophobic polystyrene (PS) block in high yields via a thiol-ene process. Following metal-coordination with Mn2+, Fe2+, Ni2+, and Zn2+, the resulting metallo-polymers were self-assembled into spherical, vesicular nanostructures, as characterized by dynamic light scattering and transmission electron microscopy (TEM) imaging.

RAFT Chemistry and Huisgen 1,3-Dipolar Cycloaddition: A Route to Block Copolymers of Vinyl Acetate and 6-O-Methacryloyl Mannose?

2007 ◽  
Vol 60 (6) ◽  
pp. 405 ◽  
Author(s):  
S. R. Simon Ting ◽  
Anthony M. Granville ◽  
Damien Quémener ◽  
Thomas P. Davis ◽  
Martina H. Stenzel ◽  
...  
Keyword(s):  
Block Copolymers ◽  
Vinyl Acetate ◽  
Self Assembly ◽  
Average Molecular Weight ◽  
Dipolar Cycloaddition ◽  
Hydrodynamic Diameter ◽  
Transmission Electron ◽  
Reversible Addition ◽  
Polymer Distribution ◽  
Two Phases

The present communication explores a novel avenue to glycopolymer-block-poly(vinyl acetate) polymers by a combination of reversible addition fragmentation chain transfer (RAFT) chemistry and Huisgen 1,3-dipolar cycloaddition (i.e., so-called ‘click’ chemistry) under mild reaction conditions. Such block copolymers are—because of the strongly disparate reactivity of the two monomers—otherwise not obtainable. Poly(vinyl acetate) that has an azide end group (Mn 6800 g mol–1, PDI 1.15) was treated with poly(6-O-methacryloyl mannose) (Mn 7600 g mol–1, PDI 1.11) in the presence of 1,8-diaza[5,4,0]bicycloundec-7-ene and copper(i) iodide. The resulting poly(vinyl acetate)-block-poly(6-O-methacryloyl mannose) had a number-average molecular weight of 15400 g mol–1 and a PDI of 1.48, which indicates that while the cycloaddition had occurred the resulting polymer distribution featured a considerable width. The resulting slightly amphiphilic block copolymer was subsequently investigated with regard to its self-assembly in aqueous solution. Dynamic light scattering studies indicated a hydrodynamic diameter of close to 200 nm. Transmission electron microscopy studies indicate the formation of rods as well as spheres with transitions between these two phases. However, the segregation between core and shell in the spheres is not pronounced; such behaviour is expected for weakly amphiphilic block copolymers.

Controlled RAFT synthesis of polystyrene-b-poly(acrylic acid)-b-polystyrene block copolymers and their self-assembly in an ionic liquid [BMIM][PF6]

e-Polymers ◽  
2011 ◽  
Vol 11 (1) ◽  
Author(s):  
Linping Zheng ◽  
Yun Chai ◽  
Yang Liu ◽  
Puyu Zhang
Keyword(s):  
Ionic Liquid ◽  
Block Copolymers ◽  
Self Assembly ◽  
Chain Transfer ◽  
Raft Polymerization ◽  
Amphiphilic Block Copolymers ◽  
Transmission Electron ◽  
Reversible Addition ◽  
Potential Applications ◽  
Increasing Temperature

AbstractThe block copolymer of polystyrene-block-polyacrylate-blockpolystyrene (PSt-PAA-PSt) has been synthesized by reversible addition fragmentation chain-transfer (RAFT) polymerization using S,S′-Bis(α,α′-dimethyl-α′′-acetic acid)-trithiocarbonate (BDATC) as chain transfer agent. Three copolymers form micelles in an ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF6]). The nanostructures of the PSt-PAA-PSt micelles formed in ionic liquid were observed by transmission electron microscopy (TEM). The self-assembled morphologies of the micelles are strongly dependent on the length of PAA block chains when the chain length of PS is fixed. The affinity of PAA chains for water and [BMIM][PF6] reverses with increasing temperature. Research results show that the copolymer with low polydispersity can be obtained by controlling polymerization, and the flexibility of amphiphilic block copolymers for controlling nanostructure in an ionic liquid presents potential applications in many arenas.

scholarly journals Alpha helical surfactant-like peptides self-assemble into pH-dependent nanostructures

Soft Matter ◽  
2021 ◽  
Vol 17 (11) ◽  
pp. 3096-3104
Author(s):  
Valeria Castelletto ◽  
Jani Seitsonen ◽  
Janne Ruokolainen ◽  
Ian W. Hamley
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Small Angle ◽  
Self Assembly ◽  
X Ray ◽  
Cryogenic Transmission Electron Microscopy ◽  
X Ray Scattering ◽  
Transmission Electron ◽  
Ph Dependent ◽  
Ray Scattering

A designed surfactant-like peptide is shown, using a combination of cryogenic-transmission electron microscopy and small-angle X-ray scattering, to have remarkable pH-dependent self-assembly properties.

Creation of Polymeric Nanostructures by Living Coordination Block Copolymerization of Allene Derivatives Having Fluoroalkyl Substituents Under Polymerization-induced Self-assembly Conditions and Their Application to Superhydrophobic Surface

2021 ◽  
Author(s):  
Yidan Cheng ◽  
Takeshi Wakiya ◽  
Shinsuke Inagi ◽  
Toshikazu Takata ◽  
Ikuyoshi Tomita
Keyword(s):  
Block Copolymers ◽  
Self Assembly ◽  
Superhydrophobic Surface ◽  
Block Copolymerization ◽  
Spontaneous Formation ◽  
Superhydrophobic Coatings

The spontaneous formation of polymeric nanostructures possessing outer fluorous segments by the living coordination block copolymerization and their application to the transparent superhydrophobic coatings are described. The block copolymers (BCPs)...

scholarly journals Low-temperature hydrothermal synthesis of hierarchical flower-like CuB2O4 superstructures

2020 ◽  
Vol 14 (2) ◽  
pp. 113-118
Author(s):  
Daniel Ursu ◽  
Anamaria Dabici ◽  
Marinela Miclau ◽  
Nicolae Miclau
Keyword(s):  
Thermal Stability ◽  
Low Temperature ◽  
Self Assembly ◽  
Hydrothermal Solution ◽  
Optical Measurements ◽  
Oriented Attachment ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
One Step

We report for the first time the fabrication of hierarchical ordered superstructure CuB2O4 with flower-like morphology via a one-step, low temperature hydrothermal method. The tetragonal structure of CuB2O4 was determined by X-ray diffraction and high-resolution transmission electron microscopy. Optical measurements attested of the quality of the fabricated CuB2O4 and high temperature X-ray diffraction confirmed its thermal stability up to 600 ?C. The oriented attachment growth and the hierarchical self-assembly of micrometer-sized platelets producing hierarchical superstructures with flower-like morphology are designed by pH of the hydrothermal solution. The excellent band gap, high thermal stability and hierarchical structure of the CuB2O4 are promising for the photovoltaic and photocatalytic applications.

scholarly journals Self-assembly of block copolymers during hollow fiber spinning: an in situ small-angle X-ray scattering study

Nanoscale ◽  
2019 ◽  
Vol 11 (16) ◽  
pp. 7634-7647 ◽  
Author(s):  
Kirti Sankhala ◽  
D. C. Florian Wieland ◽  
Joachim Koll ◽  
Maryam Radjabian ◽  
Clarissa Abetz ◽  
...  
Keyword(s):  
Block Copolymers ◽  
Hollow Fiber ◽  
Small Angle ◽  
Self Assembly ◽  
Fiber Spinning ◽  
The Self ◽  
X Ray ◽  
X Ray Scattering ◽  
Scattering Study

A study of the self-assembly of block copolymers in ordered and weakly segregated solutions after extrusion during fabrication of isoporous hollow fiber membranes.

Selective Growth of Heteroepitaxial GexSi1−x/Si Lateral Wells Using Pulsed Laser Induced Epitaxy

1991 ◽  
Vol 220 ◽  
Author(s):  
Yih Chang ◽  
J. Kramer ◽  
S. Y. Chou ◽  
T. W. Sigmon ◽  
A. F. Marshall
Keyword(s):  
Surface Defects ◽  
Pulsed Laser ◽  
Semiconductor Processing ◽  
X Ray ◽  
Transmission Electron ◽  
X Ray Imaging ◽  
Different Dimensions ◽  
Significant Line ◽  
First Time ◽  
Processing Steps

ABSTRACTPatterned GexSi1−x/Si wells are fabricated for the first time by pulsed laser induced epitaxy technique, employing two different semiconductor processing steps to grow these structures selectively. Two different dimensions of Gt0.12 Si0.55 /Si wells are sucessfully formed, in which one is 3.5 μm wide and 1700Å deep while another is 6 μm wide and 1300Å deep. Transmission electron microscopy combined with energy-dispersive X-ray imaging reveals that the 2-D Ge redistribution profiles are well defined and no significant line or surface defects observed. The 2-D Ge well redistribution behavior, governed by heat and mass transport during laser processing, are also discussed.

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