Effect of acid concentration on pore size in polymer-templated mesoporous alumina

Synthesis of mesoporous alumina with tunable structural properties

“…In addition, both the adsorption and desorption branches of the hysteresis loops for MA2P, MA4P and MA6P were nearly parallel and almost perpendicular to the relative pressure axis. This observation is often associated with porous materials consisting of agglomerated uniform particles [14,16]. Moreover, the isotherms with steep condensation steps (e.g., MA4P) still presented narrow PSD.…”

“…Nitric acid acts as a coordination agent and a pH adjuster in the synthesis system to maintain the medium acidic [9]. A recent study has pointed out that in the polymer-templated synthesis of mesoporous alumina, the role of acidic conditions was to provide protons to allow the interaction between the poly ethylene oxide (PEO) blocks and aluminium precursors to form the corona structure and the concentration of acid would also affect the micelle size [16]. The increased addition of HNO 3 resulted in an increase in the Pluronic micelle size due to the affinity of protons to the PEO blocks and also increased the NO 3 À concentration at the corona/water interface.…”

Synthesis of nanostructured alumina with ultrahigh pore volume for pH-dependent release of curcumin

“…This gure indicates that all NPA-n are amorphous alumina. This result is reasonable due to the fact that these samples are calcined at 550 C, whereas the crystallization temperature should be in the range of 800-900 C. 68 As shown in Fig. 4b, characteristic diffraction peaks of CUR are not detected in the drug-loaded NPA-n, indicating that nano-sized pores restricted crystal formation of the drug, which is an advantage in the preparation of the nanodrugs.…”

Hydrogen production by steam reforming of liquefied natural gas (LNG) over ordered mesoporous nickel–alumina catalyst

“…It has been reported that micelle size of triblock copolymer increases with increasing concentration of nitrate ions in solution, due to the salting-in effect caused by nitrate ions adsorbed in EO blocks of triblock copolymer [29]. In addition, crystallograpic water molecules separated from nickel precursor in the preparation of OMNA catalyst are also responsible for swelling of hydrophilic block [30].…”