Synthesis, Characterization, and Self-Assembly of Poly(N-vinylpyrrolidone)-block-poly(vinyl acetate)

2012 ◽  
Vol 65 (8) ◽  
pp. 1124 ◽  
Author(s):  
Nathalie Bailly ◽  
Gwenaelle Pound-Lana ◽  
Bert Klumperman
Keyword(s):  
Light Scattering ◽  
Block Copolymers ◽  
Vinyl Acetate ◽  
Self Assembly ◽  
1H Nmr Spectroscopy ◽  
Molar Mass ◽  
Chain Transfer ◽  
The Self ◽  
Ethyl Xanthate ◽  
Transmission Electron

Poly(N-vinylpyrrolidone)-block-poly(vinyl acetate) (PVP-b-PVAc) block copolymers of varying molar mass and hydrophobic block lengths were synthesized by xanthate-mediated radical polymerization. In order to control the molar mass of the hydrophilic PVP block, a xanthate chain transfer agent, S-(2-cyano-2-propyl) O-ethyl xanthate, was used. The PVP-b-PVAc block copolymer is composed of a hydrophilic and hydrophobic segment, and has the ability to self-assemble in aqueous solution. The PVP-b-PVAc block copolymers were characterized by 1H NMR spectroscopy to confirm their self-assembly in water. The critical micelle concentration was determined by fluorescence spectroscopy. A combination of dynamic light scattering, transmission electron microscopy, and static light scattering was used to further characterize the self-assembly of the block copolymers in water.

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.

scholarly journals Supramolecular Functionalizable Linear–Dendritic Block Copolymers for the Preparation of Nanocarriers by Microfluidics

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 684 ◽  
Author(s):  
Miriam Abad ◽  
Alejandro Martínez-Bueno ◽  
Gracia Mendoza ◽  
Manuel Arruebo ◽  
Luis Oriol ◽  
...  
Keyword(s):  
Block Copolymers ◽  
Self Assembly ◽  
The Self ◽  
Cross Linking ◽  
Spectroscopic Techniques ◽  
Polymeric Nanocarriers ◽  
Transmission Electron ◽  
Click Coupling ◽  
Drug Nanocarriers ◽  
Fast Synthesis

Hybrid linear–dendritic block copolymers (LDBCs) having dendrons with a precise number of peripheral groups that are able to supramolecular bind functional moieties are challenging materials as versatile polymeric platforms for the preparation of functional polymeric nanocarriers. PEG2k-b-dxDAP LDBCs that are based on polyethylene glycol (PEG) as hydrophilic blocks and dendrons derived from bis-MPA having 2,6-diacylaminopyridine (DAP) units have been efficiently synthesized by the click coupling of preformed blocks, as was demonstrated by spectroscopic techniques and mass spectrometry. Self-assembly ability was first checked by nanoprecipitation. A reproducible and fast synthesis of aggregates was accomplished by microfluidics optimizing the total flow rate and phase ratio to achieve spherical micelles and/or vesicles depending on dendron generation and experimental parameters. The morphology and size of the self-assemblies were studied by TEM, Cryogenic Transmission Electron Microscopy (cryo-TEM), and Dynamic Light Scattering (DLS). The cytotoxicity of aggregates synthesized by microfluidics and the influence on apoptosis and cell cycle evaluation was studied on four cell lines. The self-assemblies are not cytotoxic at doses below 0.4 mg mL−1. Supramolecular functionalization using thymine derivatives was explored for reversibly cross-linking the hydrophobic blocks. The results open new possibilities for their use as drug nanocarriers with a dynamic cross-linking to improve nanocarrier stability but without hindering disassembly to release molecular cargoes.

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 Semi-Fluorinated Di and Triblock Copolymer Nano-Objects Prepared via RAFT Alcoholic Dispersion Polymerization (PISA)

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2502
Author(s):  
Gregoire Desnos ◽  
Adrien Rubio ◽  
Chaimaa Gomri ◽  
Mathias Gravelle ◽  
Vincent Ladmiral ◽  
...  
Keyword(s):  
Self Assembly ◽  
Triblock Copolymer ◽  
Dispersion Polymerization ◽  
Chain Transfer ◽  
Raft Polymerization ◽  
The Self ◽  
The Core ◽  
Transmission Electron ◽  
Reversible Addition ◽  
Polymerization Conditions

A set of well-defined amphiphilic, semi-fluorinated di and triblock copolymers were synthesized via polymerization-induced self-assembly (PISA) under alcoholic dispersion polymerization conditions. This study investigates the influence of the length, nature and position of the solvophobic semi-fluorinated block. A poly(N,N-dimethylaminoethyl methacrylate) was used as the stabilizing block to prepare the di and tri block copolymer nano-objects via reversible addition-fragmentation chain transfer (RAFT) controlled dispersion polymerization at 70 °C in ethanol. Benzylmethacrylate (BzMA) and semi-fluorinated methacrylates and acrylates with 7 (heptafluorobutyl methacrylate (HFBMA)), 13 (heneicosafluorododecyl methacrylate (HCFDDMA)) and 21 (tridecafluorooctyl acrylate (TDFOA)) fluorine atoms were used as monomers for the core-forming blocks. The RAFT polymerization of these semi-fluorinated monomers was monitored by SEC and 1H NMR. The evolution of the self-assembled morphologies was investigated by transmission electron microscopy (TEM). The results demonstrate that the order of the blocks and the number of fluorine atoms influence the microphase segregation of the core-forming blocks and the final morphology of the nano-objects.

Bottom-up Evolution from Disks to High-Genus Polymersomes

2018 ◽  
Author(s):  
Claudia Contini ◽  
Russell Pearson ◽  
Linge Wang ◽  
Lea Messager ◽  
Jens Gaitzsch ◽  
...  
Keyword(s):  
Self Assembly ◽  
The Self ◽  
Amphiphilic Copolymers ◽  
Chain Entanglement ◽  
Bottom Up ◽  
New Approach ◽  
High Genus ◽  
Transmission Electron ◽  
Minimal Radius ◽  
Stop Flow

<div><div><div><p>We report the design of polymersomes using a bottom-up approach where the self-assembly of amphiphilic copolymers poly(2-(methacryloyloxy) ethyl phosphorylcholine)–poly(2-(diisopropylamino) ethyl methacrylate) (PMPC-PDPA) into membranes is tuned using pH and temperature. We study this process in detail using transmission electron microscopy (TEM), nuclear magnetic resonance (NMR) spectroscopy, dynamic light scattering (DLS), and stop-flow ab- sorbance disclosing the molecular and supramolecular anatomy of each structure observed. We report a clear evolution from disk micelles to vesicle to high-genus vesicles where each passage is controlled by pH switch or temperature. We show that the process can be rationalised adapting membrane physics theories disclosing important scaling principles that allow the estimation of the vesiculation minimal radius as well as chain entanglement and coupling. This allows us to propose a new approach to generate nanoscale vesicles with genus from 0 to 70 which have been very elusive and difficult to control so far.</p></div></div></div>

Bottom-up Evolution from Disks to High-Genus Polymersomes

2018 ◽  
Author(s):  
Claudia Contini ◽  
Russell Pearson ◽  
Linge Wang ◽  
Lea Messager ◽  
Jens Gaitzsch ◽  
...  
Keyword(s):  
Self Assembly ◽  
The Self ◽  
Amphiphilic Copolymers ◽  
Chain Entanglement ◽  
Bottom Up ◽  
New Approach ◽  
High Genus ◽  
Transmission Electron ◽  
Minimal Radius ◽  
Stop Flow

<div><div><div><p>We report the design of polymersomes using a bottom-up approach where the self-assembly of amphiphilic copolymers poly(2-(methacryloyloxy) ethyl phosphorylcholine)–poly(2-(diisopropylamino) ethyl methacrylate) (PMPC-PDPA) into membranes is tuned using pH and temperature. We study this process in detail using transmission electron microscopy (TEM), nuclear magnetic resonance (NMR) spectroscopy, dynamic light scattering (DLS), and stop-flow ab- sorbance disclosing the molecular and supramolecular anatomy of each structure observed. We report a clear evolution from disk micelles to vesicle to high-genus vesicles where each passage is controlled by pH switch or temperature. We show that the process can be rationalised adapting membrane physics theories disclosing important scaling principles that allow the estimation of the vesiculation minimal radius as well as chain entanglement and coupling. This allows us to propose a new approach to generate nanoscale vesicles with genus from 0 to 70 which have been very elusive and difficult to control so far.</p></div></div></div>

Directive Effect of Chain Length in Modulating Peptide Nano-assemblies

2020 ◽  
Vol 27 (9) ◽  
pp. 923-929
Author(s):  
Gaurav Pandey ◽  
Prem Prakash Das ◽  
Vibin Ramakrishnan
Keyword(s):  
Electron Microscopy ◽  
Amino Acids ◽  
Light Scattering ◽  
Chain Length ◽  
Self Assembly ◽  
The Self ◽  
Ionic Charge ◽  
Self Assembling ◽  
Biophysical Techniques

Background: RADA-4 (Ac-RADARADARADARADA-NH2) is the most extensively studied and marketed self-assembling peptide, forming hydrogel, used to create defined threedimensional microenvironments for cell culture applications. Objectives: In this work, we use various biophysical techniques to investigate the length dependency of RADA aggregation and assembly. Methods: We synthesized a series of RADA-N peptides, N ranging from 1 to 4, resulting in four peptides having 4, 8, 12, and 16 amino acids in their sequence. Through a combination of various biophysical methods including thioflavin T fluorescence assay, static right angle light scattering assay, Dynamic Light Scattering (DLS), electron microscopy, CD, and IR spectroscopy, we have examined the role of chain-length on the self-assembly of RADA peptide. Results: Our observations show that the aggregation of ionic, charge-complementary RADA motifcontaining peptides is length-dependent, with N less than 3 are not forming spontaneous selfassemblies. Conclusion: The six biophysical experiments discussed in this paper validate the significance of chain-length on the epitaxial growth of RADA peptide self-assembly.

Self-Assembly of Single Chain Janus Nanoparticles from Azobenzene-Containing Block Copolymers and Reversible Photoinduced Morphology Transition

2021 ◽  
Author(s):  
Wei Wen ◽  
Aihua Chen
Keyword(s):  
Block Copolymers ◽  
Experimental Research ◽  
Self Assembly ◽  
The Self ◽  
Single Chain ◽  
Morphology Transition ◽  
Janus Nanoparticles ◽  
Assembly Behavior

Self-assembly of amphiphilic single chain Janus nanoparticles (SCJNPs) is a novel and promising approach to fabricate assemblies with diversified morphologies. However, the experimental research of the self-assembly behavior of SCJNPs...

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