Silicon, macroporous porous

Ponomarev EA, Levy-Clement C (1998) Macropore formation on p-type Si in fluoride containing organic electrolytes. Electrochem Solid St Lett 1 42-45 Ponomarev EA, Levy-Clement C (2000) Macropore formation on p-type silicon. J Porous Mat 7 51-56... 

Chiolerio A, Virga A, Pandolfi P et al (2012) Direct patterning of silver particles on porous silicon by inkjet printing of a silver salt via in-situ reduction. Nanoscale Res Lett 7 1-7 Fang C, Foca E, Xu S et al (2007) Deep silicon macropores filled with copper by electrodeposition. J Electrochem Soc 154 D45-D49... 

With electrochemically etched porous silicon structures, quantum size effects are only important in microporous and mesoporous silicon. Macroporous silicon can for many properties be modeled as bulk silicon with voids therein, provided the macropores therein do not contain mesoporosity, for example. 

Relatively few studies on the synthesis of mesoporous alumina have been reported to date [8]. One of the limitations of the reported synthetic strategies is that the rate of hydrolysis (and condensation) reaction of aluminum alkoxide are much faster than that of silicon alkoxide. In this study, we proposed a novel method to prepare bimodal porous aluminas with meso- and macropores with narrow pore size distribution and well-defined pore channels. The fiamewoik of the porous alumina is prepared via a chemical templating method using alkyl caiboxylates. Here, self-assemblied micelles of carboxylic acid were used as a chemical template. Mesoporous aluminas were prepared through carefiil control of the reactants pH, while the procedures are reported elsewhere [9]. 

Porous Silicon Microcavities in Meso- and Macroporous Silicon Further Confinement of Light... 

Luminescence from Porous Electrodes As in bulk systems, photogeneration of charge carriers in a porous electrode or injection of minority carriers from solution can lead to light emission [25]. In a macroporous system in which the depletion layer can follow the contours of the porous matrix, one does not expect significant differences between bulk and porous electrodes with regard to the potential dependence of the emission. If, however, the porosity is high and the dimensions of the structures become very small (e.g. <5 nm) then special effects may be expected. These are indeed found as, for example, with nanoporous silicon. 

Another model proposed by Kohl and coworkers [77, 78] is based upon the strain - induced preferential etching described earlier. The model accounts for the formation of macropores and highly branched micropores when the silicon is rendered porous in either nonaque-ous or aqueous HF solutions, respectively. 

We carried out comparative studies of the effect of the porous structure of carbon materials on electrochemical electrode characteristics using various carbide carbons (CCs). Main structural characteristics for CCs based on silicon carbide are presented in Table 27.3 and those for titanium carbide are in Table 27.4. Specific surface areas were calculated on the basis of the nitrogen adsorption data with calculation using the DFT technique. This method is used to measure micropores and mesopores, but not macropores. 

A two-step membrane manufacturing process has been reported where a defect free Pd-alloy membrane is first prepared by sputtering deposition onto the perfect surface of a silicon wafer, for example. In a second step the membrane is removed from the wafer and transferred to a porous stainless steel support (see Figure 11.1). This allows the preparation of very thin ( 1-2 pm) defect-free membranes supported on macroporous substrates (pore size equals 2 pm). By this technique, the ratio of the membrane thickness over the pore size of the support may become less than 1, which is two orders of magnitude smaller than obtained by more conventional membrane preparation techniques. Tubular-supported palladium membranes prepared by the two-step method show a H2/N2 permselectivity equal to 2600 at 26 bars and hydrogen flux of 2477 mL(STP) min cm . Since the method enables the combination of macro-porous stainless steel supports and thin membrane layers, the support resistance is negligible. ... 

Kim JH, Kim KP, Lyu HK, Woo SH, Seo HS, Lee JH (2009) Three dimensional macropore arrays in p-type silieon fabrieated by electrochemical etching. J Korean Phys Soc 55(1) 5-9 Loni A, Canham LT (2013) Exothermic phenomena and hazardous gas release during thermal oxidation of mesoporous silicon powders. J Appl Phys 113 173505 Lysenko V, Vitiello J, Remaki B, Barbier D (2004) Gas permeability of porous silicon nanostructures. Phys Rev E 70 017301... 

Ouyang H, Christopherson M, Fauchet PM (2005) Enhanced control of porous silicon morphology fi"om macropore to mesopore formation. Phys Stat Solidi (a) 202(8) 1396-1401 Pacholski C (2013) Photonic crystal sensors based on porous silicon. Sensors 13 4694-4713 Roura P, Costa J (2002) Radiative thermal emission from silicon nanoparticles a reversed story from quantum to classical theory. Eur J Phys 23 191-203 Scherer WG, Smith DM, Stein D (1995) Deformation of silica aerogels during characterisation. JNon Cryst Solids 186 309-315... 

---