Nanostructured Colloids

4 Voided Double-Gyroid Thin Film Templates 

THF are miscible). Then the good-solvent THF which has a higher vapor pressure than water was allowed to slowly evaporate. Due to the fact that neither of the two copolymer blocks is water soluble, droplets with a high polymer and THF concentration form which Anally form colloids when all the THF has evaporated. Then, the PLA phase was selectively removed by the addition of NaOH and methanol. The nanostructured particles were then collected by centrifugation, dispersed on a substrate, and characterized by means of SEM, see Fig. 4.22. Adjusting the polymer concentration and the THF water ratio allows to control the formed particle size. 

---

On the whole, the technology utilized to produce the variety of new nanostructured colloidal materials, as outlined in this chapter, is unparalleled in its versatility and simplicity and is therefore foreseen to become widely used in the engineering of colloidal entities for various applications in the physical and life sciences. 

A synthetic alternative to this is the chemical reduction of metal salts in the presence of extremely hydrophilic surfactants have yielded isolable nanometal colloids having at least 100 mg of metal per litre of water [105], The wide range of surfactants conveniently used to prepare hydrosols with very good redispersibility properties include amphiphilic betaines A1-A4, cationic, anionic, nonionic and even environmentally benign sugar soaps. Table 3.1 presents the list of hydrophilic stabilizers used for the preparation of nanostructured colloidal metal particles, and Table 3.2 shows the wide variety of transition metal mono- and bi-metallic hydrosols formed by this method [105,120],... 

What are nanostructured colloidal particles What are hydrosols and organosols ... 

Bourgeat-Lami, E. (2002) Organic-inorganic nanostructured colloids. /. Nanosci. Nanotech., 2, 1-24. 

The assembly was initially performed for Au Si02 with very thin shells (ca. 2 nm) on 640 nm polystyrene spheres [19] and later extended for latex cores of various sizes and gold nanoparticles coated with thicker shells. Examples of nanostructured colloids formed by assembly of Au Si02 with identical cores but silica shells with various thickness are shown in Fig. 7. It is clear that, although the surface of the particles is rough, the resultant layers are very compact... 

The fuel cell is an electrochemical reactor, the required output of which is the energy released rather than the reaction product. The main fields of its application include transport systems, stationary power generation, and combined heat and power sources. What emerges from the specialist literature is that, despite the innovations and improvements made in recent years, there is still much room for further developments. " Central to the success of fuel-cell technology are the catalyst systems. This is where bi- and multi-metallic nanostructured colloids, especially those of small particle size (1-2.5 nm), scattering as nearly perfect single crystals , are important. They offer improved efficiency and tolerance against CO-... 

E. Bourgeat-Lami. Orgamc-inorgamc nanostructured colloids. J. Nanosci. Nanotechnol., 2 1-24,2002... 

V. Jokinen, P. Suvanto, A.R. Garapaty, J. Lyytinen, J. Koskinen and S. Franssila. Durable superhydrophobicity in embossed CYTOP fluoropolymer micro and nanostructures. Colloids Surfaces A, 434, 207-212 (2013). 

Zhang Y, Chen J (2014) Interface mechanism of a rapid and mild aqueous-organic method to prepare CeP04 nanostructures. Colloids Surf A Physicochem Eng 444 246-251... 

Dekany I, Kruger-Grasser R, Weiss A (1998), Selective liquid sorption properties of hydrophobized graphite oxide nanostructures . Colloid Polym Sci, 76, 570-576. 

Oluwafemi, O. S. (2009). A Novel Green Synthesis of Starch-Capped CdSe Nanostructures. Journal of Colloids and Surfaces B Biointerfaces, 73, 382-386. 

The next two chapters concern nanostructured core particles. Chapter 13 provides examples of nano-fabrication of cored colloidal particles and hollow capsules. These systems and the synthetic methods used to prepare them are exceptionally adaptable for applications in physical and biological fields. Chapter 14, discusses reversed micelles from the theoretical viewpoint, as well as their use as nano-hosts for solvents and drugs and as carriers and reactors. 

A unique feature of such DNA-directed self-assemblies is their site-selective immobilization, which makes it possible to construct well-defined nanostructures. On the other hand, the possibility of the introduction of a vast number of substitutes (like peptidic sequences, nucleoproteins, of hydrophobic hydrocarbon chains) to an adamantane core (adamantyl) makes such a process capable of designing steric colloidal and supramolecular conformations by setting hydrophobic/hydrophilic and other interactions. In addition, the rigidity of the adamantane structure can provide strength and rigidity to such self-assemblies [150]. 

Figure 2. Wet chemical formation of nanostructured metal colloids [82],...

Reetz et al. have used N-(octyl)4Br-stabilized Pd colloids (typical size, e.g., 3nm) as precursors to form so-called cortex-catalysts, where the active metal forms an extremely fine shell of less than lOnm on the supports (e.g., AI2O3). Within the first 1-4 s, the impregnation of AI2O3 pellets by dispersed nanostructured metal colloids leads to the time-dependent penetration of the support which is complete after 10 s. Cortex catalysts were reported to show a threefold higher activity in olefin hydrogenation than conventionally prepared catalysts of the same metal loading (5% Pd on AI2O3) [388]. 

U. Kreibig, H. Botmematm, J. Hormes, Nanostructured materials, micelles and colloids, in H. S. Nalwa (ed.) Handbook of Surfaces and Interfaces of Materials, Vol. 3, Academic Press, San Diego, 2001, 1. 

GustavssonM, Fredriksson H, Kasemo B, Jusys Z, Jun C, Behm RJ. 2004. Nanostructured platinum-on-carbon model electrocatalysts prepared by colloidal lithography. J Electroanal Chem 568 371-377. 

Shimoni, E. (2008). Using AFM to explore food nanostructure. Curr. Opin. Colloid Interface Sci. 13, 368-374. 

Wu YD, Wang LS, Xiao MW, Huang XJ (2008) A novel sonochemical synthesis and nanostructured assembly of polyvinylpyrrolidone-capped CdS colloidal nanoparticles. J Non-Cryst Solid 354(26) 2993-3000... 

Brust, M. and Kiely, C.J. (2002) Some recent advances in nanostructure preparation from gold and silver particles a short topical review. Colloids and Surfaces A Physicochemical and EngineeringAspects, 202 (2-3), 175-186. 

---