scholarly journals Micelle Structure Details and Stabilities of Cyclic Block Copolymer Amphiphile and Its Linear Analogues

Polymers ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 163 ◽  
Author(s):  
Brian J. Ree ◽  
Toshifumi Satoh ◽  
Takuya Yamamoto
Keyword(s):  
Structural Integrity ◽  
Positive Impact ◽  
Structural Parameters ◽  
Micelle Formation ◽  
Cyclic Polymer ◽  
X Ray Scattering ◽  
Micelle Structure ◽  
Cyclic Block ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene

In this study, we investigate structures and stabilities of the micelles of a cyclic amphiphile (c-PBA-b-PEO) composed of poly(-n-butyl acrylate) (PBA) and poly(ethylene oxide) (PEO) blocks and its linear diblock and triblock analogues (l-PBA-b-PEO and -l-PBA--b-PEO-b-PBA) by using synchrotron X-ray scattering and quantitative data analysis. The comprehensive scattering analysis gives details and insights to the micellar architecture through structural parameters. Furthermore, this analysis provides direct clues for structural stabilities in micelles, which can be used as a good guideline to design highly stable micelles. Interestingly, in water, all topological polymers are found to form ellipsoidal micelles rather than spherical micelles; more interestingly, the cyclic polymer and its linear triblock analog make oblate-ellipsoidal micelles while the linear diblock analog makes a prolate-ellipsoidal micelle. The analysis results collectively inform that the cyclic topology enables more compact micelle formation as well as provides a positive impact on the micellar structural integrity.

scholarly journals Effect of Molecular Architecture on Associating Behavior of Star-Like Amphiphilic Polymers Consisting of Plural Poly(ethylene oxide) and One Alkyl Chain

Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 460
Author(s):  
Daisuke Kugimoto ◽  
Aoi Taniguchi ◽  
Masaki Kinoshita ◽  
Isamu Akiba
Keyword(s):  
Ethylene Oxide ◽  
Average Molecular Weight ◽  
Amphiphilic Polymers ◽  
Hydrophobic Core ◽  
Molecular Architecture ◽  
Polymer Micelles ◽  
The Core ◽  
X Ray Scattering ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene

Associating behavior of star-like amphiphilic polymers consisting of two or three poly(ethylene oxide) (PEO) chains and one stearyl chain (C18) was investigated. Although the aggregation number (Nagg) of linear analogue of amphiphilic polymers monotonically decreased with increasing number-average molecular weight of PEO (Mn,PEO), the Nagg of micelles of star-like amphiphilic polymers with Mn,PEO = 550 g/mol was smaller than that with Mn,PEO = 750 g/mol, whereas that with Mn,PEO ≥ 750 g/mol showed general Mn,PEO dependence. Small-angle X-ray scattering analyses revealed that the occupied area of one PEO chain on the interface between hydrophobic core and corona layer in the micelles of star-like polymers was much narrower than that in the linear amphiphilic polymers. This result indica ted the PEO chains of star-like polymers partially took unfavorable conformation near the core–corona interface in polymer micelles. The effect of local conformation of PEO chains near the interface on the associating behavior became significant as Mn,PEO decreased. Therefore, in polymer micelles of star-like amphiphilic polymers containing PEO with Mn,PEO = 550 g/mol, the enlargement of occupied area of PEO on the core–corona interface should be caused to avoid the formation of unfavorable conformations of partial PEO chains, resulting in a decrease in Naggs.

Hybrid micelle formation from poly(ethylene oxide-b-sodium 2-acrylamido-1-propanesulfonate-b-styrene) and Fe3+ ion in aqueous solution

2010 ◽  
Vol 288 (9) ◽  
pp. 991-996 ◽  
Author(s):  
Bishnu Prasad Bastakoti ◽  
Sudhina Guragain ◽  
Yuuichi Yokoyama ◽  
Shin-ichi Yusa ◽  
Kenichi Nakashima
Keyword(s):  
Aqueous Solution ◽  
Ethylene Oxide ◽  
Micelle Formation ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene

Photodegradation Activity of Poly(ethylene oxide-b-ε-caprolactone)-Templated Mesoporous TiO2 Coated with Au and Pt

2020 ◽  
Vol 20 (8) ◽  
pp. 5276-5281 ◽  
Author(s):  
Wei-Cheng Chu ◽  
Jeonghun Kim ◽  
Minjun Kim ◽  
Abdulmohsen Ali Alshehri ◽  
Yousef Gamaan Alghamidi ◽  
...  
Keyword(s):  
Ethylene Oxide ◽  
Self Assembly ◽  
Diblock Copolymers ◽  
Charge Carriers ◽  
Nanocomposite Films ◽  
Soft Template ◽  
X Ray Scattering ◽  
Evaporation Induced Self Assembly ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene

Mesoporous TiO2 films are synthesized through evaporation-induced self-assembly using poly(ethylene oxide-b-ε-caprolactone) diblock copolymers as a soft-template. Using small-angle X-ray scattering and scanning electron microscopy, we investigate the effect of the TiO2/PEO-b-PCL ratio on the resulting nanoarchitectonic structure. After sputter-coating Au and Pt layers, these Au/TiO2 and Pt/TiO2 nanocomposite films display drastically enhanced photodegradation of rhodamine 6G under ultraviolet irradiation, due to the metal films inhibiting the rapid recombination of photogenerated charge carriers.

SAXS characterization of polymer-embedded hollow nanoparticles and of their shell porosity

2013 ◽  
Vol 46 (6) ◽  
pp. 1654-1664 ◽  
Author(s):  
Zhi Hong Chen ◽  
Sun Hye Hwang ◽  
Xiang-bing Zeng ◽  
Jongmin Roh ◽  
Jyongsik Jang ◽  
...  
Keyword(s):  
Gas Adsorption ◽  
Alternative Form ◽  
Outer Diameter ◽  
Hollow Nanoparticles ◽  
Polymer Layers ◽  
X Ray Scattering ◽  
Poly Ethylene Oxide ◽  
Inner Diameter ◽  
Poly Ethylene

Size parameters of SiO2/TiO2hollow nanoparticles (HNPs) of 25–100 nm in diameter were characterized by small-angle X-ray scattering (SAXS). On the basis of the decoupling and the Percus–Yevick approximations, and using a hollow sphere model, size information on HNPs was extracted, including average outer diameter, average inner diameter and polydispersity. Application of an alternative form factor based on hollow ellipsoids, and of a sticky hard sphere structure factor, did not improve the fit significantly. The shell porosity of the HNPs and the size of the pores in the HNP shell were further characterized by combining SAXS with gas adsorption methods. The above HNPs were then supported on a porous poly(ethylene oxide) scaffold by freeze drying from aqueous solution. To characterize the product, a multishell model was applied to fit the experimental SAXS curves and extract the following morphological information: distribution of HNPs between the surface and interior of the polymer, thickness of the polymer layers lining the outer and inner surfaces of HNPs, and densities of the outer and inner polymer layers. The work demonstrates the versatility of SAXS in obtaining key information on dissolved and polymer-supported HNPs in applications such as drug delivery and catalysis.

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