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An energy model of the formation of multiwall nanoscrolls from thin layers is proposed. It is established that the radial growth of a nanoscroll can be accompanied by variation of the ratio of its internal and external diameters. The influence of the main physical parameters of the model on this ratio is considered. [ABSTRACT FROM AUTHOR]

Energy model of formation of multiwall nanoscrolls from thin layers has been proposed. The three major factors favoring the scrolling are dimensional mismatch of the crystal lattices forming the bilayer, difference of the surface energy at the bilayer sides, and the interaction between the bilayers. Optimal cross-section geometry of the finite-length nanoscrolls with chrysotile structure has been simulated. Effects of the Young's modulus, specific surface energy, and adhesion energy on the nanoscroll morphology have been considered. [ABSTRACT FROM AUTHOR]

We have studied the effect of the structure of precursors on the formation of MgSiO(OH) nanotubes under hydrothermal conditions. The results demonstrate that a chemical match between the components of a starting mixture has an advantageous effect on the synthesis of nanotubular magnesium hydrosilicate and the morphology of the hydrothermal treatment products. [ABSTRACT FROM AUTHOR]

n explicitly solvable model of flow in a nanotube, which is caused by an elastic soliton propagating in the nanotube wall, is proposed. A mathematical basis for the model is provided by the theory of selfadjoint extensions of symmetrical operators. [ABSTRACT FROM AUTHOR]

The polymer-inorganic nanocomposites based on the aromatic polyamidoimides and the silicate nanotubes of chrysotile structure were developed. The polyamidoimides were synthesized from dicarboxyphenylphthalimide dichloride by the polycondensation with either 4,4′-diaminodiphenyl ether or 3,5-diaminobenzoic acid. The morphology, mechanical and transport properties of the nanocomposite films were studied. Distribution of nanotubes in the composites is shown to be defined by the chemical structure of the polyamidoimide. The conditions for the formation of the composites were optimized to provide a significant increase in selective permeability toward alcohol and water in the process of pervaporation at the introduction of the nanotubes in the polymer. [ABSTRACT FROM AUTHOR]

An initial stage of nanoroll formation in a hydrothermal medium is investigated – the stage of rolling of a double layer under the action of internal stresses. A critical role in the rolling process is attributed to the viscous liquid surrounding the roll. A method is proposed to calculate the liquid flow around the forming nanoroll. A calculation of the rolling process is also performed. Finally, disturbance of the liquid by the rolling nanotube is studied. [ABSTRACT FROM AUTHOR]

Nanotubes suspended in a fluid medium have been investigated by the electrooptic method. This method is based on measuring the relative changes in the intensity of light transmitted through a suspension of nanotubes with application of an external electric field. The electrooptic effect (difference in these changes for transmitted light plane-polarized along the external field and perpendicularly to it) is analyzed. For aqueous suspensions of Mg3Si2O5(OH)4 nanotubes, the field and relaxation dependences of this effect are investigated. An analysis of the results obtained suggests that nanotubes, even when their concentration in water is low, form strong stable aggregates, which, however, can be elongated and enlarged under long-term action of strong rf fields. [ABSTRACT FROM AUTHOR]

Nanotubes of the chrysotile structure were obtained under hydrothermal conditions in the series of hydrosilicates of the Mg3Si2O5(OH)4-Co3Si2O5(OH)4 system. Substitution of cobalt ions for magnesium ions affects the conditions of formation, morphology, and size of the nanotubes. The formation of nanotubes on hydrothermal treatment of the starting mixtures of cobalt metasilicate and magnesium, cobalt, and, silicon oxides and hydroxides occurs in stages, and the stage of nanotube formation is always preceded by the formation of a lammellar structure. [ABSTRACT FROM AUTHOR]

The possibility of modifying the properties of poly(4,4′-oxydiphenylene)pyromellitimide films by introducing into prepolymer solutions nanoparticles of various compositions and structures [hydrosilicate nanoparticles in the form of layered structures (montmorillonite) and nanotubes; carbon nanofibers] was examined. New intercalating agents, tetranuclear aromatic diamines, were suggested for pretreatment of montmorillonite prior to introduction into heat-resistant polymers. The mechanical characteristics of the nanocomposites with hydrosilicate nanotubes can be optimized by chemical pretreatment of the nanotubes prior to introduction into the polymer matrix. Introduction of the above-named nanoparticles into the polymer matrix appreciably increases the elastic modulus of the material. The largest increase in the elastic modulus is observed with hydrosilicate nanotubes of the chrysotile structure, coated with an aromatic modifier. [ABSTRACT FROM AUTHOR]

Mg3Si2O5(OH)4-Ni3Si2O5(OH)4 nanotubes with the chrysotile structure and MgO : NiO molar ratios of 1 : 2 and 2 : 1 are synthesized by hydrothermal reactions at temperatures from 250 to 450°C and pressures from 30 to 100 MPa. The reaction path and kinetics, as well as the dimensions and morphology of the resulting nanotubes, are shown to depend on the nature of the starting reagents, chemical composition of the reaction system, and hydrothermal synthesis conditions. At higher nickel concentrations in the hydrous silicates, nanotube formation requires higher temperatures, longer hydrothermal treatment times, and higher NaOH concentrations in the reaction system. [ABSTRACT FROM AUTHOR]

The article discusses the fluid flow of waveguide modes in nanochannel. It states that the fluid flow is associated with the quantum interaction between the nanotube wall and the fluid and is investigated through the zero-range potential (ZRP) model's framework. It also mentions that ZRP model records the structure discreteness and simplifies quantum-mechanical calculations.

The article discusses the evolution and formation of nanoscroll ensembles basing on layered-structure compounds. Nanoscrolls belong to a nanotube group with different composition and morphology, and considered as transient structures that transforms to nanotubes of the cylinder-in-cylinder type. It mentions that basing on the original size distribution of plates and assuming the absence of nanotubes, the time of evolution of size distribution of nanotubes and nanoscrolls can be determined.

The article examines the dynamics of nanotube twisting in a viscous fluid. According to the authors, the synthesis of nanotubular formations and the study of their structure and properties make up a new line of inquiry in materials science. The probe of the dynamics of layer twisting for compounds with a layered structure and their subsequent recrystallization with the formation of nanotubes with a certain morphology is of great importance for understanding the mechanism of nanotube formation.

A correction to the article related to impact of component ratio in the compound focused on nanotubular and platelike particles is presented.