Validation of BET specific surface area for heterogeneous Ziegler-Natta catalysts based on αS-plot

The Influence of Alcohols in Driving the Morphology of Magnesium Chloride Nanocrystals

“…The influence of the synthesis protocol in determining the structural, morphological, and surface properties of the final catalyst is well known in industrial practice . It is recognized that the nature of the molecular adduct and the alcohol employed in the synthesis of MgCl 2 drastically influence the porosity of the catalyst and, hence, its activity and the properties of the obtained polymer . “Superactive” catalyst supports have been prepared from molecular adducts between MgCl 2 and alcohols .…”

“…[31] It is recognizedt hat the natureo ft he molecular adduct and the alcohol employed in the synthesis of MgCl 2 drastically influence the porosity of the catalysta nd, hence, its activity and the properties of the obtained polymer. [31][32][33] "Superactive" catalysts upports have been prepared from molecular adducts between MgCl 2 and alcohols. [34,35] However,aclear correlation between the synthesis variables and the properties of the catalyst at the nanoscale is still missing.Since the 1980s, [36,37] ZN catalysts have been traditionally investigated by meanso fm olecular mechanics and quantummechanical computations aimed at identifying possible reaction mechanisms for olefin polymerization on what were supposed to be the most stable MgCl 2 surfaces in the presence of LBs and Ti x Cl 4Àx .I nt he last decade, the application of DFT and DFT methods including dispersion (DFT-D) to elucidatet he energeticso ft he interaction and the local structures of TiCl 4 (or Ti x Cl 3x )a nd the LB at these surfaces [25,[38][39][40][41][42][43][44][45][46] substantially re- [a] Dr.…”

“…[31] It is recognizedt hat the natureo ft he molecular adduct and the alcohol employed in the synthesis of MgCl 2 drastically influence the porosity of the catalysta nd, hence, its activity and the properties of the obtained polymer. [31][32][33] "Superactive" catalysts upports have been prepared from molecular adducts between MgCl 2 and alcohols. [34,35] However,aclear correlation between the synthesis variables and the properties of the catalyst at the nanoscale is still missing.…”

Process modeling and evaluation of petroleum refinery wastewater treatment through response surface methodology and artificial neural network in a photocatalytic reactor using poly ethyleneimine (PEI)/titania (TiO2) multilayer film on quartz tube

“…On the other hand, for this kind of isotherm the gradient once decreased around 0.1-0.3 of P/P 0 and then increased from 0.7 to 1.0 of P/P 0 . These results suggest the presence of at least two steps of pore filling, one at very low P/P 0 associated with the pores of molecular dimensions for effectively trapping the light into the inner layers and the other at a 0.7-1.0 of P/P 0 associated with pores involving quasi-multilayer formation that proved the formation of PEI/TiO 2 thin films which was our purpose [35]. The XRD results of coated TiO 2 before and after coating did not show any significant changes in the structure of photocatalysts as a consequence of the coating and calcination processes (Fig.…”

Ziegler–Natta catalysts supported on crystalline and amorphous MgCl2/THF complexes

“…Although the BET method is not very reliable for Ziegler-Natta catalysts [29], an apparent increase in the specific surface area is obtained with interaction of TiCl 4 with Sup-A and Sup-B. Also pore volumes 0.13 cm 3 /g for Cat-A and 0.07 cm 3 /g for Cat-B were clearly higher than those for Sup-A and Sup-B (0.05 and 0.004 cm 3 /g, respectively).…”