viernes, 3 de febrero de 2012

Fabrication of Nanosized Cuprous Oxide Using Fehling's Solution


A facile method for the synthesis of Cu2O nanoparticles by reduction of Fehling's solution, using glucose as reducing agent. Copper sulfate is used as a precursor with potassium sodium tartarate in an alkaline media to produce Fehling's solution. The precipitation of Cu2O nanoparticles from this solution in the presence of glucose was controlled by addition of SLES or Triton-X 100 as surfactants. The reactions have been carried out at 60_C with high repeatability. The purification process of the Cu2O product does not require expensive methods, since a solid product isobtained from a reaction in liquid phase.

Materials

  1. 1   CuSO4.5H2O,
  2. 2    Potassium sodium tartarate tetrahydrate,
  3. 3    Triton-X 100,
  4. 4    Sodium laureth sulfate
  5. 5    NaOH analytical grade



Preparation of Cu2O Nanoparticles

Fehling's solution which is comprised of equal parts of the following solutions was first made:
Solution 1: Was made by dissolving of copper (II) sulfate pentahydrate (6.9 g 0.02 mol) in distilled water (100 mL).
Solution 2: Was made by dissolving of potassium sodium tartarate tetrahydrate (34.6 g) and sodium hydroxide (12 g) in distilled water (100 mL).
50 mL of each of the above solutions were mixed together in a beaker and Triton X-100 or SLES (2 g) was added to the mixture and vigorously stirred for 15 m. To this mixture, aqueous solution containing 5 g of glucose in 50 mL water was added and the whole content was then heated at 60° under continuous stirring. A brick-red solid of Cu2O precipitated after a short period of reaction time. The solid was filtered off, washed with deionized water (3 times) and ethanol (2 times) and it was dried in an oven at 80°C for 3 h to afford nanosized Cu2O, 1.38 g (97% yield based n the used copper sulfate; each mole of copper sulfate produces 0.5 mole of Cu2O).

Tomado de :

Fabrication of Nanosized Cuprous Oxide Using Fehling's Solution
M. Kooti  and L. Matouri
Transaction F: Nanotechnology
Vol. 17, No. 1, pp. 73-78


Facile preparation of water-soluble fluorescent gold nanoclusters


A simple one-pot strategy of preparing small fluorescent AuNCs using a mild reductant, tetrakis-
(hydroxymethyl)phosphonium chloride (THPC). For biological imaging applications, a zwitterionic functional ligand, D-penicillamine (DPA), was chosen as a capping agent to endow the gold clusters with good stability in aqueous solvent.

Materiales


1. Tetrakis(hydroxymethyl) phosphonium chloride (THPC, P(CH2OH)4Cl, 80% aqueous solution),
2. D-penicillamine (DPA),
3. Rhodamine 6G
4. Gold(III) chloride trihydrate (HAuCl4.3H2O)
5. Sodium borohydride (NaBH4)
6. High purity deionized water

Síntesis


12 ml THPC (80%) was added to 47 ml NaOH solution (6 mM) at 37 C. The mixture was stirred for 3
min, followed by rapid addition of a solution of HAuCl4 (0.67ml, 2% by mass) and DPA (2.5 ml, 0.1 M). The reaction, during which the colorless solution slowly turned light yellow, was stopped after stirring for 15 h.


As-prepared AuNCs were purified by triple centrifugation filtration, using Nanosep filters (PallNanosep, Ann Arbor, MI) with a molecular weight cut-off of 3 kDa to remove impurities. The yellowish DPA–AuNCs
remaining on the filter could be re-suspended readily in water,and the solution was stored at 4 C for later use

Tomado de:


Facile preparation of water-soluble fluorescent gold nanoclusters for cellular imaging applications

Li Shang,a Ren e M. D€orlich,a Stefan Brandholt,a Reinhard Schneider,b Vanessa Trouillet,c Michael Bruns,c
Dagmar Gerthsenb and G. Ulrich Nienhaus

Nanoscale, 2011, 3, 2009

http://dx.doi.org/10.1039/c0nr00947d






Preparation of Silver Nanoparticles


Uniform silver nano particles can be obtained through the reduction of silver ions by ethanol at a temperature of
80°C to 100°C under atmospheric conditions [4]. In this synthesis process, 20 ml of aqueous solution containing silver nitrate (0.5g of AgNO3), 1.5 g sodium linoleate (C18H32ONa), 8 ml ethanol and 2 ml linoleic acid (C18H32O2) are added in a capped tube under agitation. The system is sealed and treated at the temperatures between 80°C to100°C for 6 hours.


Materiales
1.       silver nitrate   à 5g
2.       sodium linoleate à 15 g
3.       Ethanol à 50 mL
4.       linoleic acid à 50 mL


TTomado de:

PPreparation of Silver Nanoparticles and 
Their Characterization

R. Das, S. S. Nath, D. Chakdar, G. Gope, R. Bhattacharjee


www.azonano.com/oars.asp