Dear Abhishek,

The following is the generally used method for the preparation of layered double hydroxide nanoparticles:

General LDH preparation procedure:

LDH materials can be readily synthesized in the laboratory. Direct synthesis is the single most widely used method of preparation (Braterman et al., 2004b). This involves nucleating and growing the metal hydroxide layer by mixing an aqueous solution containing a mixture of two metal salts (MII+/MIII+) and a base whereby sodium hydroxide is usually the pre-eminent choice. Variations of the method

include titration at constant or varied pH and buffered precipitation (Broecker and Marosi, 1971; Rives and Angeles Ulibarri, 1999; Woltermann, 1984; Yamaoka et al., 1989). The simplest buffer of all is an excess of divalent metal during titration at varied pH. In this technique, the desired metal–metal ratio is obtained by fine-tuning

the amount of added base.

An Example of LDH preparation procedure:

Layered double hydroxide nanoparticles were synthesized following procedures published elsewhere (Xu et al., 2006b). Briefly, Mg(NO3)2 (3 mmol) and Al(NO3)3 (1 mmol) were dissolved in 10 mL deionized water and quickly added to 40 mL NaOH solution (6 mmol). The mixture was stirred at room temperature for 10 min and the resulting slurry was collected via centrifugation (5 min, 4500 min−1 ). The pellet was washed twice with 40 mL deionized water, and then manually resuspended in 50 mL deionized water. The inhomogeneous suspension

was transferred to a Teflon lined steel pressure vessel and heated to 100 °C for 16 h. The resulting transparent, homogenous suspension contained approximately 3 mg mL−1 of Mg2Al(OH)6NO3 nanoparticles (yield: 63%) as calculated from the Mg and Al concentrations determined by inductive coupled plasma ionisation optical emission spectroscopy (ICP-OES, Varian Vista Pro instrument). Different variations

of the synthesis protocol were used to investigate the effects the synthesis parameters have on the size of the pristine particles, i.e., the temperature during synthesis was varied between 273 K and 363 K, while hydrothermal treatment duration and temperature were varied between 2 h and 48 h and 80 °C and 150 °C, respectively.

As-obtained LDH nanoparticle suspensions were characterized by photon correlation spectroscopy on a Nanosizer Nano ZS instrument (Malvern Instruments) to determine the particle size distribution and the zeta potential of the obtained LDH nanoparticles in aqueous phase. LDH particles were imaged using a JEOL JSM-2010 transmission electron microscope (TEM) at the acceleration voltage of 200 kV.

Xu, Z.P., Lu, G.Q., 2006. Layered double hydroxide nanomaterials as potential cellular drug delivery agents. Pure and Applied Chemistry 78 (9), 1771–1779.

For more on this topic and the references depicted in the above text, please see the publication contained in the following link:

https://www.researchgate.net/publication/222183529_Controlled_preparation_of_layered_double_hydroxide_nanoparticles_and_their_application_as_gene_delivery_vehicles

Hoping this will be helpful,

Rafik

Article Controlled preparation of layered double hydroxide nanoparti...