The deviations occurred in the grafting performance can be due to the steric effect
and polarity effect of the combination of ASC and comonomers in acquis medium.
Because of the high number of P atoms in ATMP, the steric effect
was great, which was not conducive to the formation of the dense membrane.
With the increase of molecular weight, carbon chain, and volume of PAEs, steric effect
of biological reaction was increased.
Essentially, the steric effect
relates to the spatial arrangement of atoms in the molecule, especially as the arrangement impacts a chemical reaction.
With the increase of the EO units, the esterification rate of dodecyl alcohol polyoxyethylene ethers decreased, which could mainly be due to steric effect
. After preliminary purification, the purity of the products was also estimated by the integral values from their [sup.1]H NMR spectra.
At the same time, SJ-1 particles are adsorbed on the surface of clay particles; sulfonic acid group can chemically react to [Na.sup.+] and [Ca.sup.2+] in salt; the steric effect
of polyoxyethylene side chain in particles is large.
Compared to aromatic imidazolium and pyridinium cations, the chiral ionic liquids 1 have a greater steric effect
around the asymmetric point, which is most likely to produce high catalytic activities and selectivities.
The large steric effect
of [Et.sub.2]Cit weakens the coordination of [Ca.sup.2+] ion compared with that of [Na.sub.3]Cit.
Because of steric effect
of alkyl group in the aromatic rings,
This steric effect
appears in the values of Arrhenius [E.sub.act].
(17) This relayed steric effect
would account for increased activation energy of the transition state; hence, it may justify the observed hydrolysis rate.
"The implications are rather large because the cornerstone of our understanding of the structure of molecules is the steric effect
," says Goodman.