Emulsions stabilized by carbon nanotube-silica nanohybrids.
نویسندگان
چکیده
Emulsions have been stabilized by carbon nanotube-silica nanohybrids. The as-prepared nanotube-silica particles generate water-in-oil (w/o) emulsions, regardless of the water/oil volume ratio used. The emulsion volume fraction was much higher than that obtained with nanotubes only, and it was found to increase with water/oil ratio due to an increasing amount of water retained in the emulsion droplets. However, beyond a certain water/oil ratio, the emulsion fraction rapidly decreased. This point of collapse is a strong function of the amount of carbon nanotube-silica particles in the system. Oxidation of the nanohybrids by nitric acid can effectively modify the particle surfaces and change the resulting emulsion properties. The treatment in nitric acid increases the density of functional groups on the carbon nanotubes. Depending on the extent of functionalization, the effect of oxidation can vary from increasing the volume of emulsion stabilized to reversing the type of emulsion to oil-in-water (o/w). The emulsions are remarkably stable against coalescence and sedimentation and can be easily separated by filtration or centrifugation, which make them suitable for applications in interfacial catalytic processes in which the catalyst can be easily recovered after reaction.
منابع مشابه
Crude Oil Interfacial Tension Reduction and Reservoir Wettability Alteration with Graphite or Activated Carbon/Silica Nanohybrid Pickering Emulsions
In this research, two carbon structures silica nanohybrids Pickering emulsions were prepared. Graphite and activated carbon were carbon allotropes with different morphologies of laminar and spherical, respectively. The effect of carbon morphology investigated on the related silica nanohybrids Pickeringemulsions for C-EOR. Therefore, nanohybrids were prepared with graphite and activated carbon t...
متن کاملSynthesis and Properties of Carbon Nanotube-Grafted Silica Nanoarchitecture-Reinforced Poly(Lactic Acid)
A novel nanoarchitecture-reinforced poly(lactic acid) (PLA) nanocomposite was prepared using multi-walled carbon nanotube (MWCNT)-grafted silica nanohybrids as reinforcements. MWCNT-grafted silica nanohybrids were synthesized by the generation of silica nanoparticles on the MWCNT surface through the sol-gel technique. This synthetic method involves organo-modified MWCNTs that are dispersed in t...
متن کاملNanostructured carbon-metal oxide hybrids as amphiphilic emulsion catalysts.
Nanohybrids composed of "onion-like" carbon, single-walled (SWCNTs) or multi-walled carbon nanotubes (MWCNTs) fused to silica or alumina particles have been compared as stabilizers of water/oil emulsions and interfacial catalysts. The amphiphilic character of these nanohybrids makes them effective in stabilizing emulsions (up to 85 % of total volume) comprising of small droplets (less than 40 μ...
متن کاملCondensation/Hydrogenation of Biomass- Derived Oxygenates in Water/Oil Emulsions Stabilized by Nanohybrid Catalysts
The synthesis of fuel-range molecules by condensation of biomass-derived furfural and acetone has been studied in a biphasic emulsion system. Nanohybrids composed of basic oxide nanoparticles fused to carbon nanotubes have been used to simultaneously stabilize water/oil emulsions and catalyze the condensation reaction. Under the same conditions, higher conversions and higher fractions of fuel-r...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Langmuir : the ACS journal of surfaces and colloids
دوره 25 18 شماره
صفحات -
تاریخ انتشار 2009