Synthesis of Diblock Copolymer Nanoparticles via RAFT Alcoholic Dispersion Polymerization: Effect of Block Copolymer Composition, Molecular Weight, Copolymer Concentration, and Solvent Type on the Final Particle Morphology

2012 ◽  
Vol 46 (1) ◽  
pp. 128-139 ◽  
Author(s):  
Daniel Zehm ◽  
Liam P. D. Ratcliffe ◽  
Steven P. Armes
Keyword(s):  
Molecular Weight ◽  
Block Copolymer ◽  
Diblock Copolymer ◽  
Dispersion Polymerization ◽  
Particle Morphology ◽  
Copolymer Composition ◽  
Final Particle ◽  
Copolymer Concentration ◽  
Solvent Type

A variety of morphologies in diblock copolymer/homopolymer blends

1989 ◽  
Vol 47 ◽  
pp. 346-347
Author(s):  
Edwin L. Thomas ◽  
Karen I. Winey
Keyword(s):  
Molecular Weight ◽  
Block Copolymer ◽  
Diblock Copolymer ◽  
Copolymer Composition ◽  
Molecular Weights ◽  
Copolymer Concentration ◽  
Wide Range ◽  
Homopolymer Blends ◽  
Long Range Ordering ◽  
Double Diamond

A wide range of morphologies and thereby physical properties can be achieved in block copolymer/homopolymer blends by varying the copolymer composition, copolymer concentration and molecular weights. Recently we investigated micelle shape transitions in diblock copolymer with homopolymer blends at low copolymer concentration. In this paper we study the microstructure over a wider concentration range for a polystyrene-polybutadiene (PS/PB) diblock copolymer of molecular weight 20.5 × 103/20.5 × 103 blended with 17.2 × 103 molecular weight homopolystyrene (hPS).Figure 1 shows schematically a possible spectrum of microdomain structures dependent on the copolymer concentration of a lamellar PS/PB and hPS. Below the critical micelle concentration (CMC) the block copolymer is molecularly dispersed in the homopolymer exhibiting a homogeneous phase. As diblock concentration increases the minority (i.e. PB) forms spherical and/or cylindrical micelles randomly dispersed in the hPS. Further increases in diblock concentration induces long range ordering of various microdomains. In addition three biphasic regions are proposed in which two phases coexist: isotropic cylinders with ordered cylinders, ordered cylinders with ordered bicontinuous double diamond (OBDD), and OBDD with swollen lamellae.

Morphologies in Blends of Diblock Copolymer and Homopolymer: Morphology Diagrams and the Intermaterial Dividing Surface

1991 ◽  
Vol 248 ◽  
Author(s):  
Karen I. Winey
Keyword(s):  
Molecular Weight ◽  
Diblock Copolymer ◽  
Mean Curvature ◽  
Morphological Data ◽  
Copolymer Composition ◽  
Binary Blends ◽  
Morphological Transitions ◽  
The Mean ◽  
Dividing Surface ◽  
Double Diamond

AbstractBinary blends of diblock copolymer (AB) and homopolymer (hA) self assemble upon solvent evaporation into a great variety of microphase separated morphologies. The ordered lamellar, bicontinuous double diamond, cylindrical and spherical morphologies were observed by TEM and SAXS in our studies, as well as a range of micellar morphologies.The mean curvature (H) and the area per copolymer junction (σj), which characterize the intermaterial dividing surface, increased with increasing homopolymer concentration in the blend and/or with decreasing homopolymer molecular weight. These trends were generally obeyed both between and within ordered morphology types. The increase in H and σj was related to an increased degree of mixing between the homopolymer and the block of the copolymer.Two types of isothermal morphology diagrams were constructed to consolidate the extensive morphological data and to illustrate the general morphological transitions in AB/hA blends. The constant molecular weight morphology diagrams illustrated the interdependence of the copolymer composition and the homopolymer concentration. The constant copolymer composition diagrams emphasized the importance of the relative homopolymer molecular weight and the overall blend composition.

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.

scholarly journals RAFT dispersion polymerization of glycidyl methacrylate for the synthesis of epoxy-functional block copolymer nanoparticles in mineral oil

2019 ◽  
Vol 10 (5) ◽  
pp. 603-611 ◽  
Author(s):  
Philip J. Docherty ◽  
Matthew J. Derry ◽  
Steven P. Armes
Keyword(s):  
Block Copolymer ◽  
Diblock Copolymer ◽  
Glycidyl Methacrylate ◽  
Dispersion Polymerization ◽  
Chain Transfer ◽  
Mineral Oil ◽  
Functional Block ◽  
Reversible Addition ◽  
Stearyl Methacrylate

Epoxy-functional poly(stearyl methacrylate)-poly(glycidyl methacrylate) (PSMA-PGlyMA) diblock copolymer nanoparticles are synthesized via reversible addition–fragmentation chain transfer (RAFT) dispersion polymerization of glycidyl methacrylate (GlyMA) in mineral oil at 70 °C.

Block Copolymer Thin Films Above and Below the Order-Disorder Transition Temperature

2000 ◽  
Vol 629 ◽  
Author(s):  
Ratchana Limary ◽  
Peter F. Green
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Molecular Weight ◽  
Transition Temperature ◽  
Block Copolymer ◽  
Film Thickness ◽  
Diblock Copolymer ◽  
Diblock Copolymers ◽  
Microphase Separation ◽  
Disorder Transition Temperature

ABSTRACTSymmetric diblock copolymers undergo a disorder to order transition below a microphase separation transition temperature. In this temperature range the structure is characterized by alternating lamellae of thickness L. In thin film geometries, the lamellae are oriented normal to the substrate if there is a preferential interaction between either of the block constituents and the substrate/copolymer or copolymer/vacuum interfaces. Depending on the relation between the film thickness and L, the topography of the film might comprise of holes, islands or spinodal-like structures. We show that in a polystyrene-b-poly(methyl methacrylate) diblock copolymer of molecular weight 20, 000 g/mol, above the microphase separation transition temperature, the topography of the film depends on the thickness. A heirarchy of bicontinuous patterns and holes is observed with increasing film thickness for films thinner than 35 nm.

scholarly journals Polystyrene Microbeads by Dispersion Polymerization: Effect of Solvent on Particle Morphology

2014 ◽  
Vol 2014 ◽  
pp. 1-4 ◽  
Author(s):  
Lei Jinhua ◽  
Zhou Guangyuan
Keyword(s):  
Molecular Weight ◽  
Dispersion Polymerization ◽  
Particle Morphology ◽  
Polystyrene Microspheres ◽  
Pure Ethanol ◽  
Molecular Weights ◽  
Effect Of Solvent ◽  
Ethanol Content ◽  
Ubbelohde Viscometer ◽  
Scanning Electron

Polystyrene microspheres (PS) were synthesized by dispersion polymerization in ethanol/2-Methoxyethanol (EtOH/EGME) blend solvent using styrene (St) as monomer, azobisisobutyronitrile (AIBN) as initiator, and PVP (polyvinylpyrrolidone) K-30 as stabilizer. The typical recipe of dispersion polymerization is as follows: St/Solvent/AIBN/PVP = 10 g/88 g/0.1 g/2 g. The morphology of polystyrene microspheres was characterized by the scanning electron microscopy (SEM) and the molecular weights of PS particles were measured by the Ubbelohde viscometer method. The effect of ethanol content in the blend solvent on the morphology and molecular weight of polystyrene was studied. We found that the size of polystyrene microspheres increased and the molecular weight of polystyrene microspheres decreased with the decreasing of the ethanol content in the blend solvent from 100 wt% to 0 wt%. What is more, the size monodispersity of polystyrene microspheres was quite good when the pure ethanol or pure 2-Methoxyethanol was used; however when the blend ethanol/2-Methoxyethanol solvent was used, the polystyrene microspheres became polydisperse. We further found that the monodispersity of polystyrene microspheres can be significantly improved by adding a small amount of water into the blend solvent; the particles became monodisperse when the content of water in the blend solvent was up to 2 wt%.

Porous membranes from acid decorated block copolymer nano-objects via RAFT alcoholic dispersion polymerization

2016 ◽  
Vol 7 (10) ◽  
pp. 1899-1906 ◽  
Author(s):  
Lakshmeesha Upadhyaya ◽  
Mona Semsarilar ◽  
Rodrigo Fernández-Pacheco ◽  
Gema Martinez ◽  
Reyes Mallada ◽  
...  
Keyword(s):  
Thin Film ◽  
Block Copolymer ◽  
Methyl Methacrylate ◽  
Diblock Copolymer ◽  
Self Assembly ◽  
Dispersion Polymerization ◽  
Porous Membranes

Acid decorated diblock copolymer nano-objects were prepared by polymerization-induced self-assembly via RAFT dispersion polymerization of methyl methacrylate. Spheres were used to prepare thin film membranes.

scholarly journals Dispersion polymerization of n-butylacrylate under the action of acrylic acid and N-isopropylacrylamide copolymers

2019 ◽  
pp. 34-38 ◽  
Author(s):  
N. S. Serkhacheva ◽  
E. V. Chernikova ◽  
N. I. Prokopov ◽  
M. S. Balashov ◽  
V. V. Ogay ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Particle Size ◽  
Block Copolymer ◽  
Block Copolymers ◽  
Acrylic Acid ◽  
Particle Size Distribution ◽  
Dispersion Polymerization ◽  
High Yield ◽  
Alcohol Medium ◽  
Water Alcohol

The regularities of dispersion radical polymerization of n-butylacrylate in water-alcohol medium under the action of polymer tritiocarbonates based on copolymers of acrylic acid and N-isopropylacrylamide have been investigated. The conditions for the formation of a block copolymer with controlled molecular weight and high yield have been found. The conditions of formation of stable suspensions of block copolymers with unimodal particle size distribution have been determined.

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