Diblock copolymer-azobenzene complexes through hydrogen bonding: Self-assembly and stable photoinduced optical anisotropy

2013 ◽  
Vol 51 (8) ◽  
pp. 1716-1725 ◽  
Author(s):  
Jesús del Barrio ◽  
Eva Blasco ◽  
Luis Oriol ◽  
Rafael Alcalá ◽  
Carlos Sánchez-Somolinos
Keyword(s):  
Hydrogen Bonding ◽  
Diblock Copolymer ◽  
Self Assembly ◽  
Optical Anisotropy ◽  
Photoinduced Optical Anisotropy

Self-Assembly and Photoinduced Optical Anisotropy in Dendronized Supramolecular Azopolymers

2014 ◽  
Vol 47 (3) ◽  
pp. 897-906 ◽  
Author(s):  
Jesús del Barrio ◽  
Eva Blasco ◽  
Chris Toprakcioglu ◽  
Alexandros Koutsioubas ◽  
Oren A. Scherman ◽  
...  
Keyword(s):  
Self Assembly ◽  
Optical Anisotropy ◽  
Photoinduced Optical Anisotropy

pH- and concentration-controlled self-assembly of spherical micelles with cavity, necklace and cylindrical micelles

RSC Advances ◽  
2016 ◽  
Vol 6 (52) ◽  
pp. 47174-47177
Author(s):  
Rui Qi ◽  
Yong Jin
Keyword(s):  
Hydrogen Bonding ◽  
Diblock Copolymer ◽  
Self Assembly ◽  
Cylindrical Micelles ◽  
Spherical Micelles

A novel diblock copolymer with one block composed of hydrophobic motifs, hydrogen-bonding carbamates and pH-triggered carboxy groups was developed, which could self-assemble into spherical micelles with cavity, necklaces and cylindrical micelles.

scholarly journals Hydrogen bonding strength effect on self-assembly supramolecular structures of diblock copolymer/homopolymer blends

2016 ◽  
Vol 7 (13) ◽  
pp. 2395-2409 ◽  
Author(s):  
Shih-Chi Tsai ◽  
Yung-Chih Lin ◽  
En-Li Lin ◽  
Yeo-Wan Chiang ◽  
Shiao-Wei Kuo
Keyword(s):  
Hydrogen Bonding ◽  
Diblock Copolymer ◽  
Steric Hindrance ◽  
Self Assembly ◽  
Bonding Strength ◽  
Supramolecular Structures ◽  
Homopolymer Blends ◽  
Hydrogen Bonding Strength ◽  
Strength Effect

The steric hindrance effect on the hydrogen bonding strength and self-assembly supramolecular structures of the PS-b-PVPh diblock copolymer when blended with P4VP and P2VP homopolymers was investigated.

scholarly journals Self-Assembled Bimetallic Aluminum-Salen Catalyst for the Cyclic Carbonates Synthesis

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 4097
Author(s):  
Wooyong Seong ◽  
Hyungwoo Hahm ◽  
Seyong Kim ◽  
Jongwoo Park ◽  
Khalil A. Abboud ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Self Assembly ◽  
Reaction Pathway ◽  
Kinetic Studies ◽  
Cyclic Carbonate ◽  
Reaction Conditions ◽  
Formation Reaction ◽  
X Ray ◽  
Carbonate Formation ◽  
Salen Aluminum

Bimetallic bis-urea functionalized salen-aluminum catalysts have been developed for cyclic carbonate synthesis from epoxides and CO2. The urea moiety provides a bimetallic scaffold through hydrogen bonding, which expedites the cyclic carbonate formation reaction under mild reaction conditions. The turnover frequency (TOF) of the bis-urea salen Al catalyst is three times higher than that of a μ-oxo-bridged catalyst, and 13 times higher than that of a monomeric salen aluminum catalyst. The bimetallic reaction pathway is suggested based on urea additive studies and kinetic studies. Additionally, the X-ray crystal structure of a bis-urea salen Ni complex supports the self-assembly of the bis-urea salen metal complex through hydrogen bonding.

scholarly journals Quadruple Hydrogen Bond-Containing A-AB-A Triblock Copolymers: Probing the Influence of Hydrogen Bonding in the Central Block

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4705
Author(s):  
Boer Liu ◽  
Xi Chen ◽  
Glenn A. Spiering ◽  
Robert B. Moore ◽  
Timothy E. Long
Keyword(s):  
Hydrogen Bonding ◽  
Self Assembly ◽  
Microphase Separation ◽  
Triblock Copolymers ◽  
Random Copolymer ◽  
Thermomechanical Properties ◽  
Structure Property ◽  
Scanning Calorimetry ◽  
Central Block ◽  
Quadruple Hydrogen Bonding

This work reveals the influence of pendant hydrogen bonding strength and distribution on self-assembly and the resulting thermomechanical properties of A-AB-A triblock copolymers. Reversible addition-fragmentation chain transfer polymerization afforded a library of A-AB-A acrylic triblock copolymers, wherein the A unit contained cytosine acrylate (CyA) or post-functionalized ureido cytosine acrylate (UCyA) and the B unit consisted of n-butyl acrylate (nBA). Differential scanning calorimetry revealed two glass transition temperatures, suggesting microphase-separation in the A-AB-A triblock copolymers. Thermomechanical and morphological analysis revealed the effects of hydrogen bonding distribution and strength on the self-assembly and microphase-separated morphology. Dynamic mechanical analysis showed multiple tan delta (δ) transitions that correlated to chain relaxation and hydrogen bonding dissociation, further confirming the microphase-separated structure. In addition, UCyA triblock copolymers possessed an extended modulus plateau versus temperature compared to the CyA analogs due to the stronger association of quadruple hydrogen bonding. CyA triblock copolymers exhibited a cylindrical microphase-separated morphology according to small-angle X-ray scattering. In contrast, UCyA triblock copolymers lacked long-range ordering due to hydrogen bonding induced phase mixing. The incorporation of UCyA into the soft central block resulted in improved tensile strength, extensibility, and toughness compared to the AB random copolymer and A-B-A triblock copolymer comparisons. This study provides insight into the structure-property relationships of A-AB-A supramolecular triblock copolymers that result from tunable association strengths.

Synthesis of poly(methyl methacrylate)-b-poly(acrylic acid) by DPE method

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Dong Chen ◽  
Ruixue Liu ◽  
Zhifeng Fu ◽  
Yan Shi
Keyword(s):  
Molecular Weight ◽  
Acrylic Acid ◽  
Methyl Methacrylate ◽  
Diblock Copolymer ◽  
Self Assembly ◽  
Gel Permeation Chromatography ◽  
Amphiphilic Diblock Copolymer ◽  
Poly Methyl Methacrylate ◽  
Copolymer Poly ◽  
Poly Acrylic Acid

AbstractAmphiphilic diblock copolymer poly(methyl methacrylate)-b-poly(acrylic acid) (PMMA-b-PAA) was prepared by 1,1-diphenylethene (DPE) method. Firstly, free radical polymerization of methyl methacrylate was carried out with AIBN as initiator in the presence of DPE, giving a DPE-containing PMMA precursor with controlled molecular weight. tert-Butyl acrylate (tBA) was then polymerized in the presence of the PMMA precursor, and PMMA-b-PtBA diblock copolymer with controlled molecular weight was prepared. Finally, amphiphilic diblock copolymer PMMA-b-PAA was obtained by hydrolysis of PMMA-b-PtBA. The formation of PMMA-b-PAA was confirmed by 1H NMR spectrum and gel permeation chromatography. Transmission electron microscopy and dynamic light scattering were used to detect the self-assembly behavior of the amphiphilic diblock polymers in methanol.

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