Synthesis of Dendronized Diblock Copolymers via Ring-Opening Metathesis Polymerization and Their Visualization Using Atomic Force Microscopy

2007 ◽  
Vol 129 (31) ◽  
pp. 9619-9621 ◽  
Author(s):  
Sridhar Rajaram ◽  
Tae-Lim Choi ◽  
Marco Rolandi ◽  
Jean M. J. Fréchet
Keyword(s):  
Atomic Force Microscopy ◽  
Ring Opening ◽  
Diblock Copolymers ◽  
Ring Opening Metathesis Polymerization ◽  
Metathesis Polymerization ◽  
Force Microscopy ◽  
Atomic Force

Tunable Organogelator from Alkyl-Polypeptide Diblock Prepared by Ring-Opening Polymerization

2014 ◽  
Vol 67 (1) ◽  
pp. 59 ◽  
Author(s):  
Chongyi Chen ◽  
Decheng Wu ◽  
Wenxin Fu ◽  
Zhibo Li
Keyword(s):  
Atomic Force Microscopy ◽  
Organic Solvents ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Low Concentration ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Circular Dichroïsm ◽  
Β Sheet

Three alkyl-polypeptide hybrid amphiphiles were synthesized by the ring-opening polymerization (ROP) of γ-(2-methoxyethoxy)esteryl-l-glutamate N-carboxyanhydride (l-EG1Glu NCA) using alkylamine, i.e. C6H13NH2, C14H29NH2, and C16H33NH2, as initiators. As-prepared alkyl-poly-l-EG1Glu hybrids were found to form clear organogels in several organic solvents at low concentration. FTIR and circular dichroism characterizations suggested that poly-l-EG1Glu formed a predominantly β-sheet conformation, which accounted for the gelation. Transmission electron and atomic force microscopy characterizations revealed that these copolymers formed nanoribbon structures in THF.

Thin Films of Poly(isoprene-b-ethylene Oxide) Diblock Copolymers on Mica: An Atomic Force Microscopy Study

Langmuir ◽  
2013 ◽  
Vol 29 (7) ◽  
pp. 2339-2349 ◽  
Author(s):  
Michail Kalloudis ◽  
Emmanouil Glynos ◽  
Stergios Pispas ◽  
John Walker ◽  
Vasileios Koutsos
Keyword(s):  
Thin Films ◽  
Atomic Force Microscopy ◽  
Ethylene Oxide ◽  
Diblock Copolymers ◽  
Microscopy Study ◽  
Atomic Force Microscopy Study ◽  
Force Microscopy ◽  
Atomic Force

Effects of nanoparticles on phase morphology in thin films of phase-separated diblock copolymers

2017 ◽  
Vol 32 (S1) ◽  
pp. S141-S150
Author(s):  
Dieter Jehnichen ◽  
Doris Pospiech ◽  
Peter Friedel ◽  
Andriy Horechyy ◽  
Andreas Korwitz ◽  
...  
Keyword(s):  
Thin Films ◽  
Atomic Force Microscopy ◽  
Phase Separation ◽  
Diblock Copolymers ◽  
Force Microscopy ◽  
Atomic Force ◽  
Gold Silver ◽  
Lateral Distance ◽  
Morphology Changes ◽  
Periodic Nanostructure

This study investigates the morphology changes in thin diblock copolymer (DiBCP) films occurring in the interaction with modified nanoparticles (NPs). Magnetite (Fe3O4) and silica (SiOx) were prepared and used. Poly(pentyl methacrylate-b-methyl methacrylate) (PPMA-b-PMMA) (70/30 mol mol−1, hcp cylinders of the PMMA phase) DiBCP were employed to prepare thin films having thicknesses to realize standing cylinders in pure DiBCP films. The investigations aimed at two topics: (1) morphology after controlled incorporation of organo-modified NP (gold, silver, Fe3O4, SiOx) and (2) additional solvent vapour annealing (SVA) with tetrahydrofuran (and chloroform for comparison). The laterally ordered morphology in thin films was examined by GISAXS and atomic force microscopy. Keeping the same type of morphology in nanocomposites, the dimensions of the periodic nanostructure altered depending on type and amount of incorporated NP. It was found that SiOx clusters enlarge the lateral distance of the PMMA cylinders, whereas metallic NPs reduce this parameter. Applying SVA improves the phase separation slightly, whereas lateral distances were kept constant or were reduced a little. Switching of domain orientation upon SVA could not be detected in the presence of NPs located at the polymer/substrate interface.

Polydispersity control in ring opening metathesis polymerization of amphiphilic norbornene diblock copolymers

Polymer ◽  
2003 ◽  
Vol 44 (17) ◽  
pp. 4943-4948 ◽  
Author(s):  
Sufi R Ahmed ◽  
Steven E Bullock ◽  
Arthur V Cresce ◽  
Peter Kofinas
Keyword(s):  
Ring Opening ◽  
Diblock Copolymers ◽  
Ring Opening Metathesis Polymerization ◽  
Metathesis Polymerization

INTERRELATIONS BETWEEN MORPHOLOGY AND SOFTENING BEHAVIOR IN SELF-ASSEMBLED POLY (BUTADIENE-BLOCK-(STYRENE-STAT-BUTADIENE)) COPOLYMERS

2016 ◽  
Vol 89 (3) ◽  
pp. 392-405 ◽  
Author(s):  
C. A. Da Silva ◽  
M. Weydert ◽  
H. Budde ◽  
U. Wendler ◽  
M. Menzel ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Diblock Copolymers ◽  
Morphological Changes ◽  
Relaxation Dynamics ◽  
Scanning Calorimetry ◽  
Force Microscopy ◽  
Volume Fractions ◽  
Softening Behavior ◽  
Atomic Force ◽  
Styrene Content

ABSTRACT Two series of poly(butadiene-block-(styrene-stat-butadiene) (PB-SBR) diblock copolymers were synthesized to study interrelations between microphase-separated state and relaxation dynamics. Series I consists of six symmetric PB-SBR samples (ΦSBR ∼ 0.50) with different styrene contents in the random SBR block (21 mol% ≤ xS,SBR ≤ 52 mol%). Series II contains six asymmetric PB-SBR diblock copolymers with almost constant styrene content in the SBR block (xS,SBR = 32 ± 4 mol%) and SBR volume fractions in the range of 0.20 ≤ ΦSBR ≤ 0.69. All PB-SBR diblock copolymers have a total molecular weight of about 200 kg/mol with 1,2-vinyl content of about 8.5 and 15.8 mol% in the soft PB and in the hard SBR block, respectively. A novel synthesis route has been developed so as to maintain low 1,2-vinyl contents in both blocks and a random distribution of the styrene units in the SBR block. The softening behavior of non–cross-linked PB-SBR diblocks was investigated by differential scanning calorimetry, providing first information about miscibility. The morphology of cross-linked PB-SBR diblock copolymers, which have been vulcanized with sulfur at 150 °C using standard procedures, was studied by atomic force microscopy. Dynamic shear measurements aimed at understanding the influence of morphological changes on the segmental dynamics of both phases, αPB and αSBR, were performed on vulcanized samples. Atomic force microscopy results and shear data indicate that symmetric diblock copolymers with styrene content higher than 27 mol% in the SBR block are well microphase separated. Strongly segregated states are also observed for asymmetric diblock copolymers with volume fractions 0.28 ≤ ΦSBR ≤ 0.60 showing cylindrical and lamellar morphologies. The origin of changes in the αPB and αSBR dynamics depending on morphology and segregation strengths is considered. Implications for the use of rubbery PB-SBR block copolymers in composites for tire treads are discussed.

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