Micellar Structure in Solutions of an Ultralong Chain Zwitterionic Surfactant

Ottewill, R. H.; Rennie, A. R.; Laughlin, Robert G.; Bunke, G.

doi:10.1021/la00022a023

Cited by 9 publications

(7 citation statements)

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“…Tabet et al have synthesized partially deuterated caprolactones by hydrogenation of deuterated olefinic lactones, but provided no synthetic details . Ottewill et al briefly described the Baeyer–Villager oxidation to convert cyclohexanone- d 10 to ε-caprolactone- d 10 with m -CPBA in 21 h . However, the crude ε-caprolactone- d 10 obtained was used directly in a subsequent reaction, and no yield or spectroscopic information for ε-caprolactone- d 10 was presented.…”

Section: Resultsmentioning

confidence: 99%

Selectively Deuterated Poly(ε-caprolactone)s: Synthesis and Isotope Effects on the Crystal Structures and Properties

Chang

et al. 2018

Macromolecules

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Selective deuteration is an important tool for many analytical techniques including neutron scattering and spectroscopies. However, the availability of deuterated materials is limited because of the challenges in their synthesis. Here, we report the synthesis of partially and fully deuterated ε-caprolactone monomers and their corresponding polymers, poly(ε-caprolactone)s (PCLs), and the investigation of isotope effects on their crystalline structures and physical properties. Deuteration of PCLs leads to smaller crystal lattices and volumes compared to protiated PCLs by the amount proportional to the deuteration levels. The linear trend suggests that the volume isotope effect in PCL is primarily governed by the vibrations of C−D and C−H bonds. The large intrachain contraction of deuterated PCLs compared to that of polyethylene reported in the literature can be ascribed to the presence of polar ester groups in PCLs. Deuterated PCLs also display lower melting temperatures than protiated PCLs proportional to their deuteration levels because of weaker intermolecular interactions in deuterated polymers. FTIR spectroscopy, with support from density functional theory calculations, shows large red shifts of the stretching and bending frequencies of C−D versus C−H bonds as dictated by their relative reduced masses 13/7 , and to a smaller degree for the CO stretching frequency. This work is among the very few studies comparing the effects of partial versus full deuteration on the structures and properties in semicrystalline polymers. These results not only advance our understanding of isotope effects in polymeric materials but also provide an important avenue to design polymers with desirable properties.

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Section: Resultsmentioning

confidence: 99%

Selectively Deuterated Poly(ε-caprolactone)s: Synthesis and Isotope Effects on the Crystal Structures and Properties

Chang

et al. 2018

Macromolecules

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“…A similar conclusion was reached in a very recent small angle neutron scattering study of a similar compound, C20N5CO2, with a much longer alkyl chain. 36 As the above zwitterionic surfactants aggregate into small globular micelles without any variation of size with concentration, the first mesophase encountered as the surfactant concentration is increased is a periodic array of small globular micelles. Thus, a cubic mesophase of Pm3n symmetry, as described by Fontell37 and predicted by Charvolin and Sadoc38,39 is found with many surfactants having a bulky head group.40-45 On the contrary, the zwitterionic surfactant dodecyldimethylamine oxide, which has a smaller head group, forms larger micelles (N = 76),9,46,47 which organize into an hexagonal mesophase,48 as the concentration is increased.…”

Section: Resultsmentioning

confidence: 99%

Aqueous solutions of zwitterionic surfactants with varying carbon number of the intercharge group. 1. Micelle aggregation numbers

Kamenka¹,

Chevalier²,

Zana³

1995

Langmuir

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“…d -(Eicosyldimethylammonio)hexanoate, C 2 0 AH. This was the same material as used previously, , which was prepared by base hydrolysis of (ethylammonio)hexanoate bromide 5 at room temperature. C 20 AH is a white crystalline material which was dried for several days over silica gel in a desiccator before preparation of solutions (by weight) in D 2 O.…”

Section: Methodsmentioning

confidence: 99%

“…In previous investigations the micellar structures formed by C 20 AH in aqueous solution were examined by small angle neutron scattering. , The examination, using the contrast variation method, , of various deuterated materials, namely, C 20 D 40 HN + (CH 3 ) 2 (CH 2 ) 5 COO - , C 20 H 41 N + ((CD 3 ) 2 )(CH 2 ) 5 COO - , and C 20 H 41 N + ((CH 3 ) 2 )(CD 2 ) 5 COO - , has provided a detailed picture of the micelle structure. , The results indicated that the micelles were spherical, with a hydrocarbon core of 25 Å radius and an outer shell containing the zwitterionic head group, of thickness 5 Å. The association number was found to be ca.…”

Section: Introductionmentioning

confidence: 99%

Interaction of Small Ions with the Micellar Surface of an Ultralong Chain Zwitterionic Surfactant

et al. 1996

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In earlier work a detailed examination has been made of the structure of micelles formed from the ultralong chain zwitterionic surfactant (eicosyldimethylammonio)hexanoate. In the present work the behavior of micelles has been investigated in D2O solutions of electrolytes. The electrolytes used included sodium chloride, potassium bromide, potassium iodide, and sodium sulfate. As the electrolyte concentration increased, the micellar surface potential increased, leading to strong electrostatic interactions between the micelles. The latter depended on the anion used and indicated that binding to the micellar surface occurred in the order I- > Br- > Cl-. However, sulfate ions appeared to have little affinity for the micelle surface. Electrostatic interaction also increased with decrease of pH until at a pH below ca. 3.5 precipitation of the cationic surfactant salt occurred.

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Micellar Structure in Solutions of an Ultralong Chain Zwitterionic Surfactant

Cited by 9 publications

References 0 publications

Selectively Deuterated Poly(ε-caprolactone)s: Synthesis and Isotope Effects on the Crystal Structures and Properties

Selectively Deuterated Poly(ε-caprolactone)s: Synthesis and Isotope Effects on the Crystal Structures and Properties

Aqueous solutions of zwitterionic surfactants with varying carbon number of the intercharge group. 1. Micelle aggregation numbers

Interaction of Small Ions with the Micellar Surface of an Ultralong Chain Zwitterionic Surfactant

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