Encapsulated carbon black

Microcapsules were first used to encapsulate carbon-black particles for nonsmudging carbon paper. They are now used to encapsulate a number of quite varied active ingredients that should be released in a controlled manner. Examples are pharmaceuticals, herbicides, fungicides, and adhesives (see also Section 26.4.1). 

Comparing the three substrates that were plasma-coated in this study, it has become clear that silica is very easy to encapsulate with a plasma coating, whereas carbon black is difficult to treat because of its inert chemical surface structure. Sulfur is also more difficult to handle, but in this case the incomplete coating is an advantage because the sulfur has to be released from the encapsulation shell in order to be efficient as curing agent. In all cases, the polarity of the substrate is reduced. 

The same holds for t-BuOOH and Fe phthalocyanines encapsulated in zeolites or adsorbed on carbon black (121, 124). On the other hand, hydroperoxides have been detected as products in the oxidation of ds-pinane by t-BuOOH in the presence of zeolite Y-encapsulated FePc (133). This is irrefutable evidence of trapping of a radical by dissolved O2. Superior hydroperoxide yields are obtained with FePc in zeolite NaY in comparison with the homogeneous reaction, particularly at subambient temperature ... 

Zhong and co-workers [530] described recent results of an investigation of the electrocatal3dic oxidation of methanol using carbon-supported An and Au-Pt nanoparticle catalysts. The exploration of the bimetallic composition on carbon black support was aimed at modifying the catalytic properties for the methanol oxidation reaction at the anode in direct methanol fuel cells (DMFCs). An and Au-Pt nanoparticles of 2-3 nm sizes encapsulated in an organic monolayer were prepared, assembled on carbon black materials and treated thermally. The results have revealed that these Au-Pt nanoparticles catalysts are potentially viable candidates for use in fuel cells under a number of conditions [530],... 

Typical transfer molding compositions for encapsulation of electronic devices are mixtures of an epoxy novolac resin, a phenolic resin hardener, a catalyst, large amounts of inorganic filler (e.g., Si02) flame-retardant ingredients, internal lubricants, carbon black, and sometimes other additives such as getters to trap ionic impurities (34,35), corrosion-protection materials, and stress-relief ingredients. 

For the protection of the light sensitive IC devices, pigments are usually incorporated into the RTV encapsulant (such as low level of the carbon black and titanium dioxide). The main parameter that affects the RTV rheology may be filler incorporation and filler activity. Through the RTV silicone study, we have learned that the rheology of the RTV silicone is closely related to its coating performance. 

With samples prepared according to the method 1 the presence of mesopores shows that the zeolite crystals encapsulate the particles of the carbon black. The mesopore diameters of zeolites ZSM-5/3, ZSM-5/7 and ZSM-5/10 are in accordance with mean particle diameter of 12 nm of the Black Pearls 2000 (Table 2). It can be seen that the mesopore volume increases with increasing amount of this carbon black in the reaction mixture. 

With the ZSM-5/TMP zeolite prepared using the method 2 the presence of much broader mesopore distribution indicates that nucleation starts within the interparticle voids of aggregates of carbon black. As carbon black was impregnated with TEOS to approximately 20 % excess (compared to incipient wetness), standard zeolite crystals were formed and encapsulated the carbon matrix. The mesopore volume of the sample ZSM-5/IMP is larger than in the case of ZSM-5/10 and it attains 0.193 cm /g (Table 2). The mesopore size distribution of this sample is broader in comparison with that of the samples prepared by the secondary templating (Fig. 4). Therefore, we can assume that small clusters formed from a few carbon black particles were operative as mesopore template. 

The material can be released under defined conditions (e.g., photoinitiator) Dispersions containing the encapsulated material show improved stability against aggregation (e.g., pigments, carbon black, etc.)... 

Tiarks F, Landfester K, Antonietti M (2001) Encapsulation of carbon black by miniemulsion polymerization. Macromol Chem Phys 202 51-60... 

With this technique, the amount of carbon black that could be encapsulated in the nanocomposite increases to 80%. Although this technique was initially developed for carbon black, it has been successfully applied to other pigments, such as organic pigment and hydrophilic magnetile." " ... 

Fig. 21 Carbon-based materials suitable for encapsulation in polymers (a) carbon black, (b) carbon nanotubes, and (c) nanodiamond...

Systems consisting of a polymer, a solvent, and a nonsolvent have become of commercial importance in what is known as the microencapsulation process. In this method, the substance to be encapsulated (e.g., carbon black) is dispersed in a polymer solution so that a two-phase system results. Through, for example, the addition of a precipitant, the dissolved polymer can then be precipitated as a new third phase. [A solution of a second polymer also acts as a precipitant (see next chapter).] In this third... 

NR is one of the world s important natural resources and sihca is considered environmentahy friendly upon disposal. Thus, in terms of sustainability development, development of sihca-fihed NR nanocomposites opens new opportunities for producing green materials/products such as tyres. Traditionally, carbon black is preferred over sihca as fiber in tyres due to the challenge in dispersing sihca in rubber compounds. With the new development, e.g. in situ sol gel silica, admicellar polymerization and polymer-encapsulated sihca, the applications of nano-silica in NR and modified NRs are widened. 

The prepared carbon black is hydrophobic and easily aggregated, so the dispersion in aqueous solution is poor. Consequently, modification of the surface of carbon black is a good method for achieving better performance in aqueous systems. The methods of oxidation, grafting, plasma treatment, and encapsulation modification... 

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