Colloidal template methods

Other attempts follow the dual micellular templating approach involving a combination of block copolymers, surfactants, and alcohols [208]. The colloidal templating method produces three-dimensionally ordered macrostructures (3DOM-structures) [208]. However, even for the colloidal templating, the routes include besides the formation of the three-dimensionally arranged colloidal crystal always a second... 

PPy inverse opal patterns (ordered two-dimensional rings, hexagonal or honeycomb monolayers) over wide areas are accomplished by using a colloidal template method. The templates are made ofpoly(styrene/sodium p-styrene sulphonate) latex particles that drive the opal structure upon modulation of their packing density, thus inducing a modulation of the polymer properties [166, 167]. 

Hur, N.H., and Hong, C.S. (2004) Large magnetoresistance in three dimensionally ordered macroporous perovskite manganites prepared by colloidal templating method. J. Mater. Chem., 14, 1774-1777. 

Sadakane, M., Asanuma, T., Kubo, J. et al. (2005) Facile procedure to prepare three-dimensionally ordered macroporous (3DOM) perovskite-type mixed metal oxides by colloidal crystal templating method, Chem. Mater. 17, 3546. 

We can think of the previous methods for generating capsules as liquid templating, where self-assembly occurs around a hquid. An alternative is to use a solid template, usually called colloidal templating. The shell is generated around a solid particle that is later digested, leaving a hollow sphere (Caruso 2000). Deposition of... 

Particularly in 2D systems, control over the self-assembly of colloidal templates has offered a versatile way to produce patterned surfaces or arrays with a precision of few nanometres. Diblock copolymer micellar nanolithography (dBCML) is a versatile method that uses homopolymers or block copolymers for the production of complex surface structures with nanosized features [69], In contrast to other approaches like electron-beam lithography (EBL) and photolithography, dBCML does not require extensive equipment. In fact, it is commonly used in the fabrication of data storage devices and photonic crystals, in catalyses [70], and for the design of mesoporous films and nanoparticle arrays [71]. 

Ayral et al. [75] showed that the template method can also be applied to hydrosols of colloidal metal oxide particles in view of the preparation of tailor-made porous material. In order to produce macroporous silica materials... 

Three-dimensionally ordered macroporous ceramic with high LR ion conductivity was prepared by colloidal crystal templating method using monodispersed polystyrene beads [12]. Monodispersed polystyrene beads with 3 pm diameter were dispersed in water and then filtrated by using a membrane filter under a small pressure difference. After this treatment, polystyrene beads were accumulated on the membrane filter with closed pack structure, as shown in Fig. 4.2. Then, the membrane consisting of accumulated polystyrene beads was removed from the membrane filter and put on a glass substrate. After drying at room temperature, the... 

Fig. 12.7 Schematic diagram describing hollow capsule production by exploiting colloidal templating and self-assembly methods [12.8). Explanation see text.

There are many ingenious and sueeessful routes now developed for nanociystalline synthesis some rely on gas phase reactions followed by produet dispersal into solvents [7, 9, 13, 14 and 15]. Others are adaptations of classic colloidal syntheses [16,17,18 and 19]. Electrochemical and related template methods can also be used to form nanostructures, especially those with anisotropic shapes [20, 21,22 and 21]. Rather than outline all of the available methods, this section will focus on two different techniques of nanocrystal synthesis which together demonstrate the general strategies. 

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