Adsorption of Polyvinylpyrrolidone over the Silica Surface: As Affected by Pretreatment of Adsorbent and Molar Mass of Polymer Adsorbate

Table 1

Physicochemical properties of AEROSIL OX 50, as per the manufacturer information.

Source	BET surface area	PZC at pH		pH	Primary particle size	Tapped approximate density
Evonik Industries	50 + 15 (m^2 g^−1)	3.2	≥99.8	3.8–4.8	0.4 (µm)	.130 (g/L)

“PZC at pH” signifies the PZC (point of zero charge) at pH at which surface charge of the particle is zero.