Journal ArticleDOI
The effects of shape on the interaction of colloidal particles
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In this article, it was shown that colloids in general are apt to exhibit considerable deviations from Raoult's law and that crystalline phases retaining a fair proportion of solvent may separate from concentrated solutions.Abstract:
Introdzution. The shapes of colloidal particles are often reasonably compact, so that no diameter greatly exceeds the cube root of the volume of the particle. On the other hand, we know many coiloids whose particles are greatly extended into sheets (bentonite), rods (tobacco virus), or flexible chains (myosin, various Iinear polymers). In some instances, a t least, solutions of such highly anisometric particles are known to exhibit remarkably great deviations from Raoult’s law, even to the extent that an anisotropic phase may separate from a solution in which the particles themselves occupy but one or two per cent of the total volume (tobacco virus, bentonite). We shall show in what follows how such results may arise from electrostatic repulsion between highly anisometric particles. Most colloids in aqueous solution owe their stability more or less to electric charges, so that each particle will repel others before they come into actual contact, and effectively claim for itself a greater volume than what it actuaily occupies. Thus, we can understand that colloids in general are apt to exhibit considerable deviations from Raoult’s law and that crystalline phases retaining a fair proportion of solvent may separate from concentrated solutions. However, if we tentatively increase the known size of the particles by the known range of the electric forces and multiply the resulting volume by four in order to compute the effective van der Waal’s co-volume, we have not nearly enough to explain why a solution of 2 per cent tobacco virus in 0.005 normal NaCZ forms two phases.read more
Citations
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Journal ArticleDOI
Water-mediated structuring of bone apatite
Yan Wang,Stanislas Von Euw,Francisco M. Fernandes,Sophie Cassaignon,Mohamed Selmane,Guillaume Laurent,Gérard Pehau-Arnaudet,Cristina Coelho,Laure Bonhomme-Coury,Marie-Madeleine Giraud-Guille,Florence Babonneau,Thierry Azaïs,Nadine Nassif +12 more
TL;DR: It is demonstrated that water orients apatite crystals through an amorphous calcium phosphate-like layer that coats the crystalline core of bone Apatite, providing an extended local model of bone biomineralization.
Book ChapterDOI
Molecular theory of liquid crystals
TL;DR: The lattice theory of liquids consisting of rod-like molecules is discussed in this paper with emphasis on polymers exhibiting nematic or cholesteric liquid crystallinity, and the axial ratio of the Kuhn segment is the relevant parameter for order in lyotropic liquid-crystalline systems.
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Carbon nanotubes in liquid crystals
TL;DR: A review of the literature on carbon nanotube (CNT) dispersion in liquid crystals (LCs), focusing mainly on the approaches where the aim is to align CNTs along the LC director field, but also covering briefly the proposed possibility to enhance thermotropic LCs by CNT doping.
Journal ArticleDOI
Microstructural regimes of colloidal rod suspensions, gels, and glasses
TL;DR: In this paper, the authors classified a set of literature measurements on more than fifteen different colloidal materials and thereby distinguish between regimes of gelation and vitrification, and suggested directions for future research in the arrested dynamics, the nonlinear rheology, and the absolute lower limit of gels and glasses of colloidal rods.
Journal ArticleDOI
Landau–de Gennes modelling of nematic liquid crystal colloids
Miha Ravnik,Slobodan Žumer +1 more
TL;DR: In this article, the free energy of nematic liquid crystal colloids is discussed and the numerical finite difference relaxation technique is explained as an efficient tool for the minimisation of the energy.
References
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Journal ArticleDOI
The Role of Attractive and Repulsive Forces in the Formation of Tactoids, Thixotropic Gels, Protein Crystals and Coacervates
TL;DR: In this paper, it was shown that the Coulomb attraction between the micelles and the oppositely charged ions in the solution gives an excess of attractive force which must be balanced by the dispersive action of thermal agitation and another repulsive force.