Growing crystals form a cavity when placed against a wall. The birth of the cavity is observed both by optical microscopy of sodium chlorate crystals (NaClO_{3}) growing in the vicinity of a glass surface, and in simulations with a thin film model. The cavity appears when growth cannot be maintained in the center of the contact region due to an insufficient supply of growth units through the liquid film between the crystal and the wall. We obtain a nonequilibrium morphology diagram characterizing the conditions under which a cavity appears. Cavity formation is a generic phenomenon at the origin of the formation of growth rims observed in many experiments, and is a source of complexity for the morphology of growing crystals in natural environments. Our results also provide restrictions for the conditions under which compact crystals can grow in confinement.

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We present a continuum model describing dissolution and growth of a crystal contact confined against a substrate. Diffusion and hydrodynamics in the liquid film separating the crystal and the substrate are modeled within the lubrication approximation. The model also accounts for the disjoining pressure and surface tension. Within this framework, we obtain evolution equations which govern the non-equilibrium dynamics of the crystal interface. Based on this model, we explore the problem of dissolution under an external load, known as pressure solution. We find that in steadystate, diverging (power-law) crystal-surface repulsions lead to flat contacts with a monotonic increase of the dissolution rate as a function of the load. Forces induced by viscous dissipation then surpass those due to disjoining pressure at large enough loads. In contrast, finite repulsions (exponential) lead to sharp pointy contacts with a dissolution rate independent on the load and on the liquid viscosity. Ultimately, in steady-state the crystal never touches the substrate when pressed against it, independently from the nature of the crystal-surface interaction due to the combined effects of viscosity and surface tension.

We report on the modeling of the formation of a cavity at the surface of crystals confined by a flat wall during growth in solution. Using a continuum thin film model, we discuss two phenomena that could be observed when decreasing the thickness of the liquid film between the crystal and the wall down to the nanoscale. First, in the presence of an attractive van der Waals contribution to the disjoining pressure, the formation of the cavity becomes subcritical, i.e., discontinuous. In addition, there is a minimum supersaturation required to form a cavity. Second, when the thickness of the liquid film between the crystal and the substrate reaches the nanoscale, viscosity becomes relevant and hinders the formation of the cavity. We demonstrate that there is a critical value of the viscosity above which no cavity will form. The critical viscosity increases as the square of the thickness of the liquid film. A quantitative discussion of model materials such as calcite, sodium chlorate, glucose and sucrose is provided.

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Antibodies have become the Swiss Army tool for molecular biology and nanotechnology. Their outstanding ability to specifically recognise molecular antigens allows their use in many different applications from medicine to the industry. Moreover, the improvement of conventional structural biology techniques (e.g., X-ray, NMR) as well as the emergence of new ones (e.g., Cryo-EM), have permitted in the last years a notable increase of resolved antibody-antigen structures. This offers a unique opportunity to perform an exhaustive structural analysis of antibody-antigen interfaces by employing the large amount of data available nowadays. To leverage this factor, different geometric as well as chemical descriptors were evaluated to perform a comprehensive characterization.

The forces exerted by growing crystals on the surrounding materials play a major role in many geological processes, from diagenetic replacement to rock weathering and uplifting of rocks and soils. Although crystallization is a nonequilibrium process, the available theoretical prediction for these forces are based on equilibrium thermodynamics. Here we show that nonequilibrium effects can lead to a drop of the crystallization force in large pores where the crystal surface dissociates from the surrounding walls during growth. The critical pore size above which such detachment can be observed depends only on the ratio of kinetic coefficients and cannot be predicted from thermodynamics. Our conclusions are based on a physical model which accounts for the nonequilibrium kinetics of mass transport, and disjoining pressure effects within the thin liquid film separating the crystal and the surrounding walls. Our results suggest that the maximum size of the pores that can sustain crystallization forces close to the equilibrium prediction ranges from micrometers for salts to a millimetre for low solubility minerals such as calcite. These results are discussed in the light of recent experimental observations of the growth of confined salt crystals.

Recent experimental and theoretical investigations of crystal growth from solution in the vicinity of an impermeable wall have shown that: (i) growth can be maintained within the contact region when a liquid film is present between the crystal and the substrate; (ii) a cavity can form in the center of the contact region due to insufficient supply of mass through the liquid film. Here, we investigate the influence of surface kinetics on these phenomena using a thin film model. First, we determine the growth rate within the confined region in the absence of a cavity. Growth within the contact induces a drift of the crystal away from the substrate. Our results suggest novel strategies to measure surface kinetic coefficients based on the observation of this drift. For the specific case where growth is controlled by surface kinetics outside the contact, we show that the total displacement of the crystal due to the growth in the contact is finite. As a consequence, the growth shape approaches asymptotically the free growth shape truncated by a plane passing through the center of the crystal. Second, we investigate the conditions under which a cavity forms. The critical supersaturation above which the cavity forms is found to be larger for slower surface kinetics. In addition, the critical supersaturation decays as a power law of the contact size. The asymptotic value of the critical supersaturation and the exponent of the decay are found to be different for attractive and repulsive disjoining pressures. Finally, our previous representation of the transition within a morphology diagram appears to be uninformative in the limit of slow surface kinetics. Crystal SUBSTRATE Crystal F z < l a t e x i t s h a 1 _ b a s e 6 4 = " P L S e 1 5 N D 2 W B x m S b u H F 6 1 A r 2 L P W o = " > A A A B 9 X i c b V D L S g N B E O z 1 G e M r 6 t H L Y B A 8 h V 0 R 9 C Q B Q T x G N A 9 I l j A 7 6 c Q h s w 9 m e p W 4 5 B O 8 6 s m b e P V 7 P P g v 7 q 5 7 0 M Q 6 F V X d d H V 5 k Z K G b P v T W l h c W l 5 Z L a 2 V 1 z c 2 t 7 Y r O 7 s t E 8 Z a Y F O E K t Q d j x t U M s A m S V L Y i T R y 3 1 P Y 9 s Y X m d + + R 2 1 k G N z S J E L X 5 6 N A D q X g l E o 3 l / 3 H f q V q 1 + w c b J 4 4 B a l C g U a / 8 t U b h C L 2 M S C h u D F d x 4 7 I T b g m K R R O y 7 3 Y Y M T F m I + w m 9 K A + 2 j c J I 8 6 Z Y e x 4 R S y C D W T i u U i / t 5 I u G / M x P f S S Z / T n Z n 1 M v E / r x v T 8 M x N Z B D F h I H I D p F U m B 8 y Q s u 0 A 2 Q D q Z G I Z 8 m R y Y A J r j k R a s m 4 E K k Y p 6 W U 0 z 6 c 2 e / n S e u 4 5 t g 1 5 / q k W j 8 v m i n B P h z A E T h w C n W 4 g g Y 0 Q c A I n u A Z X q w H 6 9 V 6 s 9 5 / R h e s Y m c P / s D 6 + A b U e J I 4 < / l a t e x i t > < l a t e x i t s h a 1 _ b a s e 6 4 = " P L S e 1 5 N D 2 W B x m S b u H F 6 1 A r 2 L P W o = " > A A A B 9 X i c b V D L S g N B E O z 1 G e M r 6 t H L Y B A 8 h V 0 R 9 C Q B Q T x G N A 9 I l j A 7 6 c Q h s w 9 m e p W 4 5 B O 8 6 s m b e P V 7 P P g v 7 q 5 7 0 Ma s m 4 E K k Y p 6 W U 0 z 6 c 2 e / n S e u 4 5 t g 1 5 / q k W ...