Relationship between Structure and Fluctuations of Lipid Nonlamellar Phases Deposited at the Solid–Liquid Interface

Abstract

The structure and dynamics of nanostructure films formed by mixtures of soy phosphatidylcholine and glycerol dioleate at the silicon-aqueous interface were studied by grazing incidence neutron spin echo spectroscopy (GINSES), specular and off-specular neutron reflectometry, and small-angle X-ray diffraction. Reverse hexagonal (H) and micellar cubic phase (Fd3m) layers at the solid-liquid interface have been identified with neutron reflectometry measurements. A preferred orientation of the liquid crystalline (LC) domains was observed only for the anisotropic H phase. The size of the LC domains was found to be about 1 micrometer as estimated from the width of the diffraction peaks. GINSES revealed that the cubic phase forms rather rigid films. In comparison, the H film was more flexible, appearing as a modified undulation spectrum of the cylinders due to the interaction with the substrate.

Non-lamellar lipid assembly at interfaces: controlling layer structure by responsive nanogel particles

“…A good fit was found using an optical model that describes the film as a single layer, with the refractive index being that of the lipids. The results are consistent with the findings of our previous study investigating the effects of spin-coating parameters on the formation of films made only of non-lamellar lipids, where the films were found to retain their reverse cubic (Fd3m) structure when deposited on solid surfaces [15,17]. Similar observations were made for bicontinuous cubic phases based on phytantriol with space group Ia3d and Pn3m at two different degrees of hydration [29].…”

“…Another approach to obtain lipid non-lamellar LC surface layers is to deposit the lipid/lipid mixture from a solution using spin-coating, followed by hydration in the aqueous solution [15,16]. This approach ensures that the LC structure expected from the phase diagram is maintained, and hence the aqueous cavities of the LC phase are intact [15,17]. The structure and dynamics of films formed by mixtures of soy phosphatidylcholine and glycerol dioleate spin-coated onto silicon substrates and hydrated in D 2 O were studied by specular and off-specular neutron reflectometry and grazing incidence neutron spin echo spectroscopy [17].…”

BornAgain: software for simulating and fitting grazing-incidence small-angle scattering

“…They involve films of water (Gutfreund et al, 2016), alkane (Fontaine et al, 2018), lipid (Nylander et al, 2017), organic semiconductor (Zykov et al, 2017) and inorganic semiconductor (Highland et al, 2017;Singh et al, 2017); microgels (Kyrey et al, 2018) and microemulsions ; templated (Li-Destri et al, 2016) and self-assembled polymer structures (Berezkin et al, 2018;Glavic et al, 2018;Xie et al, 2018); nanocolumns growing from vapor deposition (Haddad et al, 2016); Au nanoparticles during CO oxidation (Odarchenko et al, 2018); C 60 monolayer islands (Kowarik, 2017); magnetic nanoparticles (Ukleev et al, 2016(Ukleev et al, , 2017 and magnetic films (Merkel et al, 2015;Glavic et al, 2018); lithographic gratings (Pflü ger et al, 2019); and sputtered multilayers . They involve films of water (Gutfreund et al, 2016), alkane (Fontaine et al, 2018), lipid (Nylander et al, 2017), organic semiconductor (Zykov et al, 2017) and inorganic semiconductor (Highland et al, 2017;Singh et al, 2017); microgels (Kyrey et al, 2018) and microemulsions ; templated (Li-Destri et al, 2016) and self-assembled polymer structures (Berezkin et al, 2018;Glavic et al, 2018;Xie et al, 2018); nanocolumns growing from vapor deposition (Haddad et al, 2016); Au nanoparticles during CO oxidation (Odarchenko et al, 2018); C 60 monolayer islands (Kowarik, 2017); magnetic nanoparticles (Ukleev et al, 2016(Ukleev et al, , 2017 and magnetic films (Merkel et al, 2015;…”

“…Typically, the simulation yields sharper peaks than the experiment (Ukleev et al, 2016(Ukleev et al, , 2017Nylander et al, 2017). Experiment and simulation are compared in the form of 2D detector images or of 1D projections.…”

New insights into the solid–liquid interface exploiting neutron reflectivity

“…Related liquid crystalline phases deposited by spin coating and then rehydrated in contact with water have also been studied, including using off-specular scattering to measure the lateral structure e.g. [49].…”