Condensation of silica nanoparticles on a phospholipid membrane

Abstract

The structure of the transient layer at the interface between air and the aqueous solution of silica nanoparticles with the size distribution of particles that has been determined from small-angle scattering has been studied by the X-ray reflectometry method. The reconstructed depth profile of the polarizability of the substance indicates the presence of a structure consisting of several layers of nanoparticles with the thickness that is more than twice as large as the thickness of the previously described structure. The adsorption of 1,2-distearoyl-sn-glycero-3-phosphocholine molecules at the hydrosol/air interface is accompanied by the condensation of anion silica nanoparticles at the interface. This phenomenon can be qualitatively explained by the formation of the positive surface potential due to the penetration and accumulation of Na + cations in the phospholipid membrane.

Analysis of X-Ray Whispering Gallery Waves Propagating Along Liquid Meniscuses

“…Further measurements have been carried out using colloidal silica hydrosols as samples instead of deionized water. Characteristic diameters of SiO 2 particles in the hydrosols have been previously estimated in the range of 7…27 nm [2]. The advantages of the usage of the silica sols for the observation of WG effects are tied to their higher viscosity compared to clean water which leads to the lower sensibility to vibrations.…”

“…3); (b) an air-liquid surface sineshaped ripples with the Gaussian height distribution and the Gaussian correlation function. It has been found [2,3] that alkali ions form a suspended layer on the surface of silica sol. In the case of an FM sol (SiO 2 particles having size ~ 7 nm) enriched by CsOH, the previously-found depth-distribution of electron density is presented in Fig.…”

Perspectives for X-ray reflectometry with laboratory sources applied to the analysis of thin films at the surface of multicomponent liquids

“…In [16] we examined the structure of surface layering for colloidal solutions of Ludox SM-30 (30% wt. SiO 2 and 0.2% wt.…”

“…in a series of publications [13,16,17,21,22,25,26] we systematically demonstrated the possibilities of studying the structure of macroscopically flat phospholipid films at the air-liquid interfaces by X-ray reflectometry performed on a laboratory source. A key feature of these works is the analysis of experimental data within the frames of the model-independent approach, which allows us to obtain information on the transverse structure of films directly without involving any a priori models.…”

Kinetics of the formation of a phospholipid multilayer on a silica sol surface

“…According to the size distribution of nanoparticles found from the intensity of small-angle scattering, the characteristic diameter of particles in the solution is ∼ 30% larger than the value declared by the manufacturer [19,20].…”