Small-Angle X-ray Scattering Insights into the Architecture-Dependent Emulsifying Properties of Amphiphilic Copolymers in Supercritical Carbon Dioxide

2015 ◽  
Vol 119 (4) ◽  
pp. 1706-1716 ◽  
Author(s):  
David Alaimo ◽  
Daniel Hermida Merino ◽  
Bruno Grignard ◽  
Wim Bras ◽  
Christine Jérôme ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Small Angle ◽  
Emulsifying Properties ◽  
Amphiphilic Copolymers ◽  
X Ray ◽  
X Ray Scattering ◽  
Supercritical Carbon ◽  
Ray Scattering

Aggregation of Amphiphilic Molecules in Supercritical Carbon Dioxide: A Small Angle X-ray Scattering Study

Langmuir ◽  
1995 ◽  
Vol 11 (11) ◽  
pp. 4241-4249 ◽  
Author(s):  
John L. Fulton ◽  
David M. Pfund ◽  
J. B. McClain ◽  
T. J. Romack ◽  
E. E. Maury ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Small Angle ◽  
X Ray ◽  
X Ray Scattering ◽  
Amphiphilic Molecules ◽  
Scattering Study ◽  
Supercritical Carbon ◽  
Ray Scattering

A combined small-angle neutron and X-ray scattering study of block copolymers micellisation in supercritical carbon dioxide

2003 ◽  
Vol 36 (3) ◽  
pp. 660-663 ◽  
Author(s):  
Fabrizio Lo Celso ◽  
Alessandro Triolo ◽  
Fabio Triolo ◽  
Pappannan Thiyagarajan ◽  
Heinz Amenitsch ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Block Copolymers ◽  
Supercritical Carbon Dioxide ◽  
Small Angle ◽  
X Ray ◽  
X Ray Scattering ◽  
Scattering Study ◽  
Supercritical Carbon ◽  
Ray Scattering

scholarly journals Study on Crystallization Behaviors and Properties of F-III Fibers during Hot Drawing in Supercritical Carbon Dioxide

Polymers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 856 ◽  
Author(s):  
Xiaoma Ding ◽  
Haijuan Kong ◽  
Mengmeng Qiao ◽  
Zhifeng Hu ◽  
Muhuo Yu
Keyword(s):  
Mechanical Properties ◽  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Treatment Time ◽  
Orientation Factor ◽  
X Ray ◽  
X Ray Scattering ◽  
Hot Drawing ◽  
Supercritical Carbon ◽  
Ray Scattering

In order to obtain F-III fibers with high mechanical properties, pristine F-III fibers were hot drawn at the temperature of 250 °C, pressure of 14 MPa, tension of 6 g·d−1, and different times, which were 15 min, 30 min, 45 min, 60 min, 75 min, 90 min, and 105 min, respectively, in supercritical carbon dioxide (Sc-CO2) in this article. All the samples, including the pristine and treated F-III fibers, were characterized by a mechanical performance tester, wide-angle X-ray scattering (WAXS), small-angle X-ray scattering (SAXS), and thermogravimetric analysis (TGA). The results showed that the thermal stability of F-III fibers was enhanced to some extent, and the tensile strength and modulus of F-III fibers had great changes as the extension of treatment time during hot drawing in Sc-CO2, although the treatment temperature was lower than the glass transition temperature (Tg) of F-III fibers. Accordingly, the phase fraction, orientation factor fc of the (110) crystal plane, fibril length lf, and misorientation angle Bφ of all the samples were also investigated. Fortunately, the hot drawing in Sc-CO2 was successfully applied to the preparation of F-III fibers with high mechanical properties.

scholarly journals Effect of Different Pressures on Microstructure and Mechanical Performance of F-III Fibers in Supercritical Carbon Dioxide Fluid

Materials ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 690 ◽  
Author(s):  
Xiaoma Ding ◽  
Haijuan Kong ◽  
Mengmeng Qiao ◽  
Zhifeng Hu ◽  
Muhuo Yu
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Mechanical Performance ◽  
Treatment Temperature ◽  
Orientation Factor ◽  
X Ray ◽  
X Ray Scattering ◽  
Fibril Length ◽  
Supercritical Carbon ◽  
Ray Scattering

F-III fibers were treated at different pressures in supercritical carbon dioxide fluid and all samples including untreated and treated F-III fibers were characterized by a mechanical performance tester, wide-angle X-ray scattering and small-angle X-ray scattering. By studying the relationship between mechanical performance and microstructural changes of the samples, it was found that microstructural change was the main cause of variation in mechanical performance. Results revealed that the maximum tensile strength and modulus of F-III fibers were acquired at 14 MPa within the pressure range of 8 MPa to 16 MPa when the temperature, tension and time were 250 °C, 6 g·d−1 and 40 min, respectively. Correspondingly, the microstructures of the samples, including the phase fraction, crystal size, orientation factor, fibril radius, fibril length and misorientation angle, have been investigated. It was fortunate that the supercritical carbon dioxide fluid could be used as a medium during the hot-stretch process to improve the mechanical performance of F-III fibers, although the treatment temperature was lower than the glass transition temperature of the F-III fibers.

scholarly journals Homogeneous nucleation of carbon dioxide in supersonic nozzles I: experiments and classical theories

2020 ◽  
Vol 22 (34) ◽  
pp. 19282-19298
Author(s):  
Kayane K. Dingilian ◽  
Roope Halonen ◽  
Valtteri Tikkanen ◽  
Bernhard Reischl ◽  
Hanna Vehkamäki ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Small Angle ◽  
Homogeneous Nucleation ◽  
Pressure Measurements ◽  
Supersonic Nozzles ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

Small angle X-ray scattering and pressure measurements yield quantitative homogeneous nucleation rates for CO2 near 80 K.

Thermodynamic Nature of Monodisperse Polystyrene in Mixed Solvent of Cyclohexane and Antisolvent Carbon Dioxide Using Synchrotron Small-Angle X-ray Scattering

2002 ◽  
Vol 35 (27) ◽  
pp. 10114-10118 ◽  
Author(s):  
Dan Li ◽  
Zhimin Liu ◽  
Buxing Han ◽  
Guanying Yang ◽  
Liping Song ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Small Angle ◽  
Mixed Solvent ◽  
X Ray ◽  
X Ray Scattering ◽  
Monodisperse Polystyrene ◽  
Ray Scattering

The Morphology of Block Copolymer Micelles in Supercritical Carbon Dioxide by Small-Angle Neutron and X-ray Scattering

1997 ◽  
Vol 30 (5) ◽  
pp. 690-695 ◽  
Author(s):  
J. D. Londono ◽  
R. Dharmapurikar ◽  
H. D. Cochran ◽  
G. D. Wignall ◽  
J. B. McClain ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Block Copolymer ◽  
Small Angle ◽  
X Ray ◽  
X Ray Scattering ◽  
Environmentally Responsible ◽  
Theoretical Predictions ◽  
Block Copolymer Micelles ◽  
Copolymer Micelles ◽  
Ray Scattering

Above its critical point, carbon dioxide forms a super-critical fluid, which promises to be an environmentally responsible replacement for the organic solvents traditionally used in polymerizations. Many lipophilic polymers such as polystyrene (PS) are insoluble in CO2, though polymerizations may be accomplished via the use of PS-fluoropolymer stabilizers, which act as emulsifying agents. Small-angle neutron and X-ray scattering have been used to show that these molecules form micelles with a CO2-phobic PS core and a CO2-philic fluoropolymer corona. When the PS block was fixed in length and the fluorinated corona block was varied, the number of block copolymer molecules per micelle (six to seven) remained constant. Thus, the coronal block molecular weight exerts negligible influence on the aggregation number, in accordance with the theoretical predictions of Halperin, Tirrell & Lodge [Adv. Polym. Sci. (1992), 100, 31–46]. These observations are relevant to understanding the mechanisms of micellization and solubilization in supercritical fluids.

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