Advances in Colloid and Interface Science (v.163, #1)

Understanding the role of ion interactions in soluble salt flotation with alkylammonium and alkylsulfate collectors by Orhan Ozdemir; Hao Du; Stoyan I. Karakashev; Anh V. Nguyen; M.S. Celik; Jan D. Miller (1-22).
There is anecdotal evidence for the significant effects of salt ions on the flotation separation of minerals using process water of high salt content. Examples include flotation of soluble salt minerals such as potash, trona and borax in brine solutions using alkylammonium and alkylsulfate collectors such as dodecylamine hydrochloride and sodium dodecylsulfate. Although some of the effects are expected, some do not seem to be encompassed by classical theories of colloid science. Several experimental and modeling techniques for determining solution viscosity, surface tension, bubble-particle attachment time, contact angle, and molecular dynamics simulation have been used to provide further information on air–solution and solid–solution interfacial phenomena, especially with respect to the interfacial water structure due to the presence of dissolved ions. In addition atomic force microscopy, and sum frequency generation vibrational spectroscopy have been used to provide further information on surface states. These studies indicate that the ion specificity effect is the most significant factor influencing flotation in brine solutions.12C amine and sulfate surfactants can adsorb at KCl crystal surfaces but not at NaCl crystal surfaces from their brine solutions.Display Omitted► Ions of brine solutions influence flotation separation of soluble minerals. ► KCl crystals can be floated with dodecylamine hydrochloride or Na dodecylsulfate. ► NaCl crystals cannot be floated with these surfactants. ► Ion specificity is significant in flotation of soluble minerals.
Keywords: Flotation chemistry; Soluble salt minerals; Saline water; Brine solutions; Ion specificity effect; Interfacial chemistry;

Paper surfaces functionalized by nanoparticles by Ying Hui Ngo; Dan Li; George P. Simon; Gil Garnier (23-38).
Nanomaterials with unique electronic, optical and catalytic properties have recently been at the forefront of research due to their tremendous range of applications. Taking gold, silver and titania nanoparticles as examples, we have reviewed the current research works on paper functionalized by these nanoparticles. The functionalization of paper with only a very small concentration of nanoparticles is able to produce devices with excellent photocatalytic, antibacterial, anti-counterfeiting, Surface Enhanced Raman Scattering (SERS) and Surface Plasmon Resonance (SPR) performances. This review presents a brief overview of the properties of gold, silver and titania nanoparticles which contribute to the major applications of nanoparticles-functionalized paper. Different preparation methods of the nanoparticles-functionalized paper are reviewed, focusing on their ability to control the morphology and structure of paper as well as the spatial location and adsorption state of nanoparticles which are critical in achieving their optimum applications. In addition, main applications of the nanoparticles-functionalized papers are highlighted and their critical challenges are discussed, followed by perspectives on the future direction in this research field. Whilst a few studies to date have characterized the distribution of nanoparticles on paper substrates, none have yet optimized paper as a nanoparticles' substrate. There remains a strong need to improve understanding on the optimum adsorption state of nanoparticles on paper and the heterogeneity effects of paper on the properties of these nanoparticles.Display Omitted► Photocatalytic, SPR, SERS, antimicrobial properties of nanoparticles are reviewed. ► Control of morphology and structure of paper enhances nanoparticles’ performance. ► Spatial location and adsorption of nanoparticles on paper need to be optimized. ► Main applications of the nanoparticles-functionalized papers are highlighted. ► Heterogeneity and light interaction between nanoparticles and paper are critical.
Keywords: Nanoparticles; Gold; Silver; Titania; Paper; Photocatalytic; SERS; SPR; Heterogeneity;

Application studies of activated carbon derived from rice husks produced by chemical-thermal process—A review by Yue Chen; Yanchao Zhu; Zichen Wang; Ying Li; Lili Wang; Lili Ding; Xiaoyan Gao; Yuejia Ma; Yupeng Guo (39-52).
The production of functional activated carbon materials starting from cheap natural precursors using environmentally friendly processes is a highly attractive subject in material chemistry today. Recently, much attention has been focused on the use of plant biomass to produce functional carbonaceous materials, encompassing economic, environmental and social issues. Besides the classical route to produce activated carbons from fossil materials, rice husk shows clear advantages in that it can generate a variety of cheap and sustainable carbonaceous materials with attractive nanostructure and functional patterns for a wide range of applications. From a comprehensive literature review, it was found that porous carbon that derived from rice husks, in addition to having wide availability, has fast kinetics and appreciable adsorption capacities too. Porous carbon materials also play a significant role in new applications such as catalytic supports, battery electrodes, capacitors, and gas storage. In this review, an extensive list of rice husks literature has been compiled. Conclusions have been drawn from the literature reviewed, and suggestions for future research are proposed.Schematic illustration of the preparation and application that activated carbon derived from rice husk. (A) carbonization (B) activation (C) gas adsorption (D) catalytic supports (E) wastewater treatment (F) hydrogen storage (G) battery electrodes or capacitors.Display Omitted► In this review, the mechanism for the preparation of functional activated carbon materials by using cheap natural precursors rice husks and various applications has be discussed. ► From this comprehensive literature review, it was found that porous carbon that derived from rice husks, in addition to having wide availability, have fast kinetics and appreciable adsorption capacities too. Porous carbon materials also play a significant role in new applications such as catalytic supports, battery electrodes, capacitors, and gas storage. ► Moreover, this review also presents some recommendations that regards to future work.
Keywords: Rice husk; Porous carbon; Preparation; Application;

Calculation of scattering-patterns of ordered nano- and mesoscale materials by S. Förster; S. Fischer; K. Zielske; C. Schellbach; M. Sztucki; P. Lindner; J. Perlich (53-83).
Analytical expressions for the scattering patterns of ordered nano- and mesoscopic materials are derived and compared to measured scattering patterns. Ordered structures comprising spheres (fcc, bcc, hcp, sc, and bct), cylinders (hex and sq), lamellae (lam) and vesicles, as well as bicontinuous cubic structures (Ia3d, Pn3m, and Im3m) are considered. The expressions take into account unit cell dimensions, particle sizes and size distributions, lattice point deviations, finite domain sizes, orientational distributions, core/shell-structures as well a variety of peak shapes. The expressions allow to quantitatively describe, model and even fit measured SAXS and SANS-patterns of ordered or oriented micellar solutions, lyotropic phases, block copolymers, colloidal solutions, nanocomposites, photonic crystals, as well as mesoporous materials.Display Omitted► Scattering patterns of ordered nano- and mesoscale materials are calculated. ► Emphasis is on expressions and approximations that increase computational speed. ► The analytical expressions allow to fit calculated to measured scattering patterns. ► Very good agreement between calculated and measured scattering patterns is found.
Keywords: Scattering; Self-assembly; Ordering; Liquid crystals; Block copolymers;