Synthesis of α‐cobalt(ii) hydroxide using ultrasound radiation

Jeevanandam, P.; Koltypin, Yuri; Gedanken, Aharon; Mastai, Yitzhak

doi:10.1039/a908065a

Cited by 83 publications

(59 citation statements)

References 35 publications

(30 reference statements)

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“…Literature concerning the synthesis of inorganic nanoparticles is very broadly scoped and the preparation of nanoparticles of molybdenum oxide, 13 nickel hydroxide 14 and nickel oxide, 15 cobalt hydroxide, 16 Prussian blue, 17 iridium oxide 18 and tungsten oxide 19 were reported. Nevertheless, few examples of the use of these nanoparticles in electrochromic applications can be found.…”

Section: Electrochromic Nanomaterialsmentioning

confidence: 99%

Nanochromics: old materials, new structures and architectures for high performance devices

Vidotti¹,

Torresi

2008

J. Braz. Chem. Soc.

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Com o desenvolvimento da nanociência, o estudo do fenômeno do eletrocromismo desperta forte e continuado interesse devido à possibilidade de obter maiores eficiências eletrocrômicas, contrastes cromáticos, sintonização de cores e baixos tempos de resposta por meio da montagem de nanomateriais. Estas vantagens são possíveis devido à alta área superficial que os nanomateriais possuem e a enorme quantidade de moléculas orgânicas eletrocrômicas que podem ser facilmente ligadas a nanopartículas inorgânicas como TiO 2 ou SiO 2 . Somado a isto, o contato direto entre o eletrólito e os nanomateriais produz altas velocidades de transferência iônica, com a concomitante compensação de carga rápida, o que é essencial para preparar eletrodos eletrocrômicos de alto desempenho. Recentemente a técnica de deposição eletrostática camada por camada foi apresentada como uma maneira interessante de preparar diferentes arquiteturas combinando nanopartículas e polímeros. O presente trabalho mostra alguns dos últimos avanços em nanocromismo.Due to the development of nanoscience, the interest in electrochromism has increased and new assemblies of electrochromic materials at nanoscale leading to higher efficiencies and chromatic contrasts, low switching times and the possibility of color tuning have been developed. These advantages are reached due to the extensive surface area found in nanomaterials and the large amount of organic electrochromic molecules that can be easily attached onto inorganic nanoparticles, as TiO 2 or SiO 2 . Moreover, the direct contact between electrolyte and nanomaterials produces high ionic transfer rates, leading to fast charge compensation, which is essential for high performance electrochromic electrodes. Recently, the layer-by-layer technique was presented as an interesting way to produce different architectures by the combination of both electrochromic nanoparticles and polymers. The present paper shows some of the newest insights into nanochromic science. Keywords: nanochromics, nanoparticles, layer-by-layer, viologensAbbreviations ECM (ox) : electrochromic material in oxidized form; ECM (red) : electrochromic material in reduced form; CV: cyclic voltammetry; : electrochromic efficiency, defined by the relation between change in absorbance and the electric charge spent in the process; A: change in absorbance; T %: change in transmittance or contrast; : response time, the time required for a total or partial change in contrast; q: electric charge; ITO: Sn-doped indium oxide; transparent conducting material used for electrochromic measures; PB, Prussian blue: [Fe III Fe II (CN) 6 ] − , iron hexacyanoferrate; viologens: organic molecules based on 1,1-"disubstituted-4,4-bipyridinium salts"; ECP: electronic conducting polymer; MLCT; metal-ligand charge transfer; PEDOT: poly(3,4-ethylenedioxythiophene); LbL: Layer-by-Layer deposition; technique based on adsorption of alternate charged species; PANI: poly(aniline); HWCVD: hot wire chemical vapour deposition; LPEI/PB: polyethyleneimine/Prussian blue; PAH: poly(al...

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Section: Electrochromic Nanomaterialsmentioning

confidence: 99%

Nanochromics: old materials, new structures and architectures for high performance devices

Vidotti¹,

Torresi

2008

J. Braz. Chem. Soc.

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“…This pre-edge feature results from a lack of inversion symmetry in crystal sites due to the presence of tetrahedral coordination of some of the cobalt ions present in the material, supporting the above conclusions. Methods used previously to make a-Co(OH) 2 materials involved electrochemical, 15 chemical, 19,26 and sonication assisted synthesis routes, 13,14 but direct electronic measurements previously could not be carried out on the resulting materials because of the low quality powder morphology, low crystallinity and the absence of suitable thin films. Few publications report the growth of Co(OH) 2 thin films on substrates.…”

Section: 27mentioning

confidence: 99%

“…[9][10][11][12][13][14][15][16] Co(OH) 2 is used as an additive in numerous industrial processes and has potential for applications as an oil additive 17 and in alkaline secondary batteries; 18 it also displays interesting magnetic properties. 10,16 It exists in two phases: a-Co(OH) 2 10,16,19 and the much more common b-Co(OH) 2 .…”

Section: Introductionmentioning

confidence: 99%

Kinetically controlled vapor-diffusion synthesis of novel nanostructured metal hydroxide and phosphate films using no organic reagents

et al. 2006

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) and Mn 3 (PO 4 ) 2 ?7H 2 O thin films have been prepared using a kinetically controlled vapor-diffusion method. Vectorial control by diffusion of ammonia as a base catalyst into an aqueous metal salt solution yields large area (2 cm 2 ) metal hydroxide and metal phosphate films with unique structures. No supporting substrate for growth of the films is necessary in this approach. The films were characterized using X-ray powder diffraction and scanning electron microscopy. The cobalt containing films were studied in more detail using transmission electron microscopy, X-ray photoelectron spectroscopy, X-ray absorption near edge structure and various chemical analysis techniques. For the first time the electronic properties and crystal structure of these materials could be studied in thin films not influenced by the presence of an underlying substrate. For Co 5 (OH) 8 (NO 3 ) 2 ?2H 2 O films, which crystallize in a layered hydrotalcite-like structure that is homogeneous from the nanoscale to the macroscale, unprecedented photoconductivity properties were observed. Resistivity measurements show that this material is a p-type semiconductor with an unusually long minority carrier lifetime and high carrier density.

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“…The other is the inside of the collapsing bubbles, where elevated temperature and high pressures are produced. If the reaction takes place inside the collapsing bubbles, the product obtained is amorphous as a result of the extremely fast cooling rate, which occurs during collapse [20][21][22] and it is the probable way to getting the amorphous stibnite nanoparticles (ST-NP) in this investigation.…”

Section: Stibnite Characterizationmentioning

confidence: 94%

Stibnite Nanoparticles as a New Stabilizer for Poly (Methyl Methacrylate) Exposed to Gamma Irradiation

et al. 2015

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Poly (methyl methacrylate), PMMA, may be used in manufacturing of devices, which are exposed to gamma irradiation. However, the polymer undergoes significant changes in its properties during process and the use of additives is a common form to stabilize the PMMA matrix. In this way, stibnite was synthesized by sonochemical method and the amorphous powder constituted of nanospheres was obtained and investigated as additive. Commercial PMMA containing stibnite nanoparticles (ST-NP) was investigated and the samples were irradiated with gamma radiation ( 60 Co). Our results showed that the addition of ST-NP at 0.3 wt% into the PMMA decreased the number of main chain scissions caused by the irradiation process, resulting in radiolytic stabilization of the polymer matrix. Analyses of mechanical properties showed influence of the ST-NP in the physical behavior of PMMA. Our findings suggest that stibnite nanoparticles are an effective additive for PMMA used in application of radiation resistance.

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Synthesis of α‐cobalt(ii) hydroxide using ultrasound radiation

Cited by 83 publications

References 35 publications

Nanochromics: old materials, new structures and architectures for high performance devices

Nanochromics: old materials, new structures and architectures for high performance devices

Kinetically controlled vapor-diffusion synthesis of novel nanostructured metal hydroxide and phosphate films using no organic reagents

Stibnite Nanoparticles as a New Stabilizer for Poly (Methyl Methacrylate) Exposed to Gamma Irradiation

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