Effect of Hydrophobic Chain Length on the Stability and Guest Exchange Behavior of Shell-Sheddable Micelles Formed by Disulfide-Linked Diblock Copolymers

2017 ◽  
Vol 121 (41) ◽  
pp. 9708-9717 ◽  
Author(s):  
Haiyan Fan ◽  
Yixia Li ◽  
Jinxian Yang ◽  
Xiaodong Ye
Keyword(s):  
Chain Length ◽  
Diblock Copolymers ◽  
Hydrophobic Chain ◽  
The Stability

Circular dichroism and infrared study of β-turn formation in repeat peptides of elastin

1987 ◽  
Vol 52 (5) ◽  
pp. 1356-1361
Author(s):  
S. Abdel Rahman ◽  
M. Elsafty ◽  
A. Hattaba
Keyword(s):  
Circular Dichroism ◽  
Solid State ◽  
Ir Spectra ◽  
Chain Length ◽  
Room Temperature ◽  
Infrared Study ◽  
Feature Characteristic ◽  
C 50 ◽  
The Stability ◽  
Circular Dichroïsm

The conformation of elastin-like peptides Boc-Ala-Pro-Gly-Val-APEGM, Boc-Ala-Pro-Gly-Val-Gly-Val-APEGM, Boc-Ala-Pro-Gly-Val-Ala-Pro-Gly-Val-Gly-Val-APEGM, Boc-Ala-Pro-Gly-Val-Gly-Val-Ala-Pro-Gly-Val-Gly-Val-APEGM were examined in solution using circular dichroism at 30 °C, 50 °C, and 70 °C and in solid state by IR at room temperature. The studies show that the β-turn is a significant conformational feature for peptides under investigation in solution at 30 °C and 50 °C, but at 70 °C the tetra, hexa, and decapeptides show the CD feature characteristic of the β-structure while the dodecapeptide spectra show the presence of β-turn which indicates the stability of the β-turn at this chain length. The IR spectra show that in the solid state at room temperature all investigated peptides assume essentially a β-turn except the tetrapeptide which present evidence of antiparallel β-structure. The β-turn contribution in the IR spectra increases with the increase of the chain length of the peptide.

scholarly journals Effect of Surfactant Molecular Structure on Emulsion Stability Investigated by Interfacial Dilatational Rheology

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1127
Author(s):  
Yuejie Jin ◽  
Dingrong Liu ◽  
Jinhua Hu
Keyword(s):  
Emulsion Stability ◽  
Chain Structure ◽  
Interfacial Film ◽  
Future Design ◽  
Rheological Method ◽  
Viscoelastic Modulus ◽  
Hydrophobic Chain ◽  
Branched Chain ◽  
The Stability ◽  
Branched Structure

Polyglycerol polyricinolate (PGPR) and polyglycerol-2 dioleate were selected as model surfactants to construct water-in-oil (W/O) emulsions, and the effect of interfacial rheological properties of surfactant film on the stability of emulsions were investigated based on the interfacial dilatational rheological method. The hydrophobicity chain of PGPR is polyricinic acid condensed from ricinic acid, and that of polyglycerol-2 dioleate is oleic acid. Their dynamic interfacial tensions in 15 cycles of interfacial compression-expansion were determined. The interfacial dilatational viscoelasticity was analyzed by amplitude scanning in the range of 1–28% amplitude and frequency sweep in the range of 5–45 mHz under 2% amplitude. It was found that PGPR could quickly reach adsorption equilibrium and form interfacial film with higher interfacial dilatational viscoelastic modulus to resist the deformation of interfacial film caused by emulsion coalescence, due to its branched chain structure and longer hydrophobic chain, and the emulsion thus presented good stability. However, polyglycerol-2 dioleate with a straight chain structure had lower interfacial tension, and it failed to resist the interfacial disturbance caused by coalescence because of its lower interfacial dilatational viscoelastic modulus, and thus the emulsion was unstable. This study reveals profound understanding of the influence of branched structure of PGPR hydrophobic chain on the interfacial film properties and the emulsion stability, providing experimental reference and theoretical guidance for future design or improvement of surfactant.

scholarly journals Dissipative Particle Dynamics Study on Interfacial Properties of Symmetric Ternary Polymeric Blends

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1516
Author(s):  
Dongmei Liu ◽  
Kai Gong ◽  
Ye Lin ◽  
Tao Liu ◽  
Yu Liu ◽  
...  
Keyword(s):  
Interfacial Tension ◽  
Chain Length ◽  
Triblock Copolymer ◽  
Diblock Copolymers ◽  
Triblock Copolymers ◽  
Dissipative Particle Dynamics ◽  
Interfacial Properties ◽  
Particle Dynamics ◽  
Polymeric Blends ◽  
Polymer Component

We investigated the interfacial properties of symmetric ternary An/AmBm/Bn and An/Am/2BmAm/2/Bn polymeric blends by means of dissipative particle dynamics (DPD) simulations. We systematically analyzed the effects of composition, chain length, and concentration of the copolymers on the interfacial tensions, interfacial widths, and the structures of each polymer component in the blends. Our simulations show that: (i) the efficiency of the copolymers in reducing the interfacial tension is highly dependent on their compositions. The triblock copolymers are more effective in reducing the interfacial tension compared to that of the diblock copolymers at the same chain length and concentration; (ii) the interfacial tension of the blends increases with increases in the triblock copolymer chain length, which indicates that the triblock copolymers with a shorter chain length exhibit a better performance as the compatibilizers compared to that of their counterparts with longer chain lengths; and (iii) elevating the triblock copolymer concentration can promote copolymer enrichment at the center of the interface, which enlarges the width of the phase interfaces and reduces the interfacial tension. These findings illustrate the correlations between the efficiency of copolymer compatibilizers and their detailed molecular parameters.

scholarly journals Liposomes coated with hydrophobically modified hydroxyethyl cellulose: Influence of hydrophobic chain length and degree of modification

2017 ◽  
Vol 156 ◽  
pp. 79-86 ◽  
Author(s):  
Gro Smistad ◽  
Bo Nyström ◽  
Kaizheng Zhu ◽  
Marthe Karoline Grønvold ◽  
Anne Røv-Johnsen ◽  
...  
Keyword(s):  
Chain Length ◽  
Hydroxyethyl Cellulose ◽  
Hydrophobically Modified ◽  
Hydrophobic Chain

scholarly journals The multiple complexes formed by the interaction of platelet factor 4 with heparin

1980 ◽  
Vol 191 (3) ◽  
pp. 769-776 ◽  
Author(s):  
P E Bock ◽  
M Luscombe ◽  
S E Marshall ◽  
D S Pepper ◽  
J J Holbrook
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Chain Length ◽  
Salt Concentration ◽  
Human Platelet ◽  
Platelet Factor 4 ◽  
High Protein ◽  
Platelet Factor ◽  
The Stability ◽  
Very High

The anisotropy of the fluorescence of dansyl (5-dimethylaminonaphthalene-1- sulphonyl) groups covalently attached to human platelet factor 4 was used to detect the macromolecular compounds formed when the factor was mixed with heparin. At low heparin/protein ratios a very-high-molecular-weight compound (1) was formed that dissociated to give a smaller compound (2) when excess heparin was added. 2. A large complex was also detected as a precipitate that formed at high protein concentrations in chloride buffer. It contained 15.7% (w/w) polysaccharide, equivalent to four or five heparin tetrasaccharide units per protein tetramer. In this complex, more than one molecule of protein binds to each heparin molecule of molecular weight greater than about 6 × 10(3).3. The stability of these complexes varied with pH, salt concentration and the chain length of the heparin. The limit complexes found in excess of the larger heparins consisted of only one heparin molecule per protein tetramer, and the failure to observe complexes with four heparin molecules/protein tetramer is discussed.

Structural regulation of polypyrrole nanospheres guided by hydrophobic chain length of surfactants

2019 ◽  
Vol 54 (23) ◽  
pp. 14309-14319 ◽  
Author(s):  
Zekun Zhou ◽  
Yun Shao ◽  
Xiang Gao ◽  
Zhitian Liu ◽  
Qi Zhang
Keyword(s):  
Chain Length ◽  
Structural Regulation ◽  
Hydrophobic Chain
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