Disodium 4,5,6-trihy­droxy­benzene-1,3-disulfonate dihydrate

In the title compound, 2Na+·C6H4O9S2 2−·2H2O, the benzene rings of the 4,5,6-trihy­droxy­benzene-1,3-disulfonate ions, which are stacked parallel to each other forming rods parallel to the a axis, are slightly deformed (planarity, symmetry) mainly because of the high degree of substitution. The two sodium ions, located within pockets of the anion rods, are coordinated by six and seven O atoms, resulting in octa­hedral and penta­gonal-bipyramidal coordinations, respectively. In addition to these coordinative bonds towards sodium, an extended network of intra- and inter­molecular hydrogen bonds occurs

Specifics of intercultural communication: professional dialogue, etiquette, appearance in the different countries

The purpose of this study is to examine the features of etiquette around the world and get some idea of the peoples inhabiting them. Theoretical methods have been used to achieve this goal. The result of this research is more in-depth understanding of communication with representatives of other countries. Цель данного исследования заключается в том, чтобы изучить особенности этикета различных стран мира и получить определенное представление о народах, их населяющих. Для достижения этой цели были использованы общетеоретические методы. Результатом данного исследования является более углубленное понимание особенностей общения с представителями других стран

Nanoscopic poly(ethylene oxide) strands embedded in semi-interpenetrating methacrylate networks. Preparation method and quantitative characterization by field-gradient NMR diffusometry

Networks of nanoscopic strands of linear, monodisperse poly(ethylene oxide) embedded in cross-linked methacrylate matrices were prepared. Depending on the choice of matrix constituents, the diameters of these strands can be varied considerably. The samples were characterized by DSC, TEM, SEM, and fringe field gradient NMR diffusometry with respect to the strand diameter. A formalism evaluating diffusive spin-echo attenuation curves based on the tube/reptation model is presented permitting the determination of the tube diameter. Values in the range from 8 to 58 nm were found in accordance with TEM micrographs of shadow-cast freeze-fractured surfaces of the samples

Scanner‐Based Capillary Stamping

Classical microcontact printing and polymer pen lithography (PPL) involve ink transfer to substrates using solid elastomeric stamps. Ink depletion thus limits the number of successive stamping steps without reinking. Porous stamps developed to overcome this limitation are used only for manual proof‐of‐principle experiments. Here, porous composite stamps for scanner‐based capillary stamping (SCS) that can be mounted on automated printing devices designed for PPL are developed. Porous SCS composite stamps consist of a rigid controlled porous silica glass (CPG) layer and a porous polymeric stamping layer. The latter can be topographically structured with contact elements by replication molding. The mechanical stabilization by the CPG layer ensures that the contact elements are coplanar. SCS allows automated, continuous, high‐throughput patterning enabled by ink supply through the porous SCS composite stamps. Even after more than 800 consecutive stamp–substrate contacts without reinking (the porous SCS composite stamps themselves are used as ink reservoirs), ink microdroplets are deposited without deterioration of the pattern quality. However, SCS also allows supply of additional ink during ongoing stamping operations through the pore systems of the porous SCS composite stamps. SCS can easily be adapted for multi‐ink patterning and may pave the way for further upscaling of contact lithography

Reptation in artificial tubes and the corset effect of confined polymer dynamics

A spinodal demixing technique was employed for the preparation of linear poly(ethylene oxide) (PEO) confined to nanoscopic strands which in turn are embedded in a quasi-solid and impenetrable methacrylate matrix. Both the molecular weight of the PEO and the mean diameter of the strands are variable to a certain degree. Chain dynamics of the PEO in the molten state was examined with the aid of field-gradient NMR diffusometry (time scale: 10-2 s... 100 s) and field-cycling NMR relaxometry (time scale: 10 -9 s... 10-4 s). The dominating mechanism for translational displacements probed in the nanoscopic strands by either technique is shown to be reptation. A corresponding evaluation formalism for NMR difrusometry is presented. It permits the estimation of the mean PEO strand diameter. Depending on the chemical composition of the matrix, the diameters range from 9 to 58 nm. The strands were visualized by electron microscopy. On the time scale of spin-lattice relaxation time measurements, the frequency dependence signature of reptation, that is T1 ∝ νV 3/4, showed up in all samples. A "tube" diameter of only 0.6 nm was concluded to be effective on this time scale even when the strand diameter was larger than the radius of gyration of the PEO random coils. This "corset effect" is traced back to the lack of the local fluctuation capacity of the free volume in nanoscopic confinements. The confinement dimension is estimated at which the cross-over from "confined" to "bulk" chain dynamics is expected

Monolayer Structure of Arachidic Acid on Graphite

Thomas LK, Kühnle A, Rode S, Beginn U, Reichling M. Monolayer Structure of Arachidic Acid on Graphite. Journal of Physical Chemistry C. 2010;114(44):18919-18924.The self-assembly of arachidic acid (C(19)H(39)COOH) at the liquid solid interface between 1-phenyloctane (C(6)H(5)(CH(2))(7)CH(3)) and highly oriented pyrolytic graphite (HOPG) is studied by scanning tunneling microscopy (STM) to identify the structure of the monomolecular film. We observe the formation of highly ordered domains with molecules oriented in three different orientations compatible with the symmetry of the HOPG substrate, a spontaneous enantiomeric separation of the pro-chiral molecules, and reveal structural details with submolecular resolution. To determine the surface unit cell with an intrinsic calibration to the substrate atomic structure, the intermolecular distance is precisely determined from the analysis of a SIN image exhibiting a moire pattern created by the superposition of current contributions from the molecular structure with contributions from the graphite atomic lattice. The dimensions of the unit cell accommodating two molecules are vertical bar a vertical bar 0.94 nm and vertical bar b vertical bar = 2.83 nm with an angle of 85 degrees between unit cell vectors a and h. The respective molecular arrangement allows hydrogen bonding between carboxylic groups with an unrelaxed O-O bond distance of 0.31 nm