Molecular liquid-solid interface

Yackoboski K, Yeo Y H, McGonigal G C and Thomson D J 1992 Molecular position at the liquid/solid interface measured by voltage-dependent imaging with the STM Ultramicroscopy 42-44 963... 

Similarly, the precise control at the liquid-solid interface of the molecular orientation and ordering of a Pc-based triple decker, which presents dissimilar adsorption and assembling characteristics for the top and bottom moieties of the triple-decker complex, has been achieved by varying the external electric field [206], In such a system, the interaction between the intrinsic molecular dipole of the adsorbed tripledecker molecule and the external electric field is responsible for the field-induced phase transition. 

Studies on the ciearance (pi/h) of modei hydrophilic solutes such as calcein (MW 623) and dextrans FD-4 (MW 4400) and FD-40 (MW 38000) in tritiated water across the skin under the influence of US have revealed a good flux correlation with H20. Unexpectedly, the slopes obtained by linear regression of the plots were consistent for all solutes examined [116]. In other words, the permeability coefficients of the solutes were comparable with those of tritiated water and independent of molecular size up to 40 kDa under the effect of US. This can be ascribed to the above-described asymmetric collapse of transient cavitation bubbles at the liquid-solid interface, which can produce transport routes for hydrophilic solutes in the stratium corneum. 

Equations 15 and 16 develop Equation (14) for gas-to-condensed-phase transitions. It would also be desirable to develop Equation (14) for liquid-to-crystalline nucleation to assign physical meaning to An. However, development of Equation (14) is difficult both because d can be a large correction factor for liquid/solid interfaces and because the molecular density differences between liquids and solids are smaller than between gases and condensed phases (Kashchiev 1982). 

The sources of band broadening of kinetic origin include molecular diffusion, eddy diffusion, mass transfer resistances, and the finite rate of the kinetics of ad-sorption/desorption. In turn, the mass transfer resistances can be sorted out into several different contributions. First, the film mass transfer resistance takes place at the interface separating the stream of mobile phase percolating through the column bed and the mobile phase stagnant inside the pores of the particles. Second, the internal mass transfer resistance controls the rate of mass transfer between this interface and the adsorbent surface. It is composed of two contributions, the pore diffusion, which is molecular diffusion taking place in the tortuous, constricted network of pores, and surface diffusion, which takes place in the electric field at the liquid-solid interface [60]. All these mass transfer resistances, except the kinetics of adsorption-desorption, depend on the molecular diffusivity. Thus, it is important to study diffusion in bulk liquids and in porous media. 

Heckl and co-workers [140] incorporated coronene molecules into a molecular network of trimesic acid molecules. Some of the coronene molecules apparently rotated and single ones could be removed with an STM tip operated at the liquid-solid interface. The authors report that coronone molecules alone do not self-organize in heptanoic acid on graphite - the support of the trimesic acid molecule network is necessary. 

Shimizu and co-workers [164] have achieved molecular resolution on 5,10,15,20-tetra(4-octacyloxyphenyl)porphyrins (CigOPP) and Rh(Ci8OPP) mixtures (ratio 1 9) with STM at the liquid-solid interface of phenyloctane and graphite. 

Additional difficulties in formulating an adsorption theory for the liquid - solid interface result from a variety of interactions between components of a liquid mixture and from a complex structure of the adsorbent, which may possess different types of pores and strong surface heterogeneity. Our considerations will be limited to physical adsorption on heterogeneous solid surfaces of components of comparable molecular sizes from non-electrolytic (non ideal or ideal) miscible binary liquid mixtures. 

Many different isotherms have been derived for molecular adsorption at interfaces, including the liquid gas, liquid liquid, and liquid solid interfaces. Some of these isotherms can be shown to be approximate versions of the general isotherm derived here. 

MJ Waner, M Gilchrist, M Schindler, M Dantos. Imaging the molecular dimensions and oligomerization of proteins at liquid/solid interfaces. J Phys Chem 102 1649-1657, 1998. 

In this contribution, we focus on the formation of monolayer networks at the liquid-solid interface and the parameters controlhng the molecular ordering, highlighting the role of intermolecular interactions, the solvent and the substrate (Fig. 2). Reducing the dimensionality of the crystal system from 3D to 2D simplifies the design of the network topologies to ID and 2D networks. We discuss the formation of multicomponent networks and pay a lot of at-... 

---