Comparative toxicity study of three surface-modified titanium dioxide nanoparticles following subacute inhalation

Table 1 Characteristics of the test items

EU/JRC-code	PPD (nm)	Surface - character - modified with - specific surface (m²/g)	Name	Crystal type
NM-103	20	Hydrophobic Coated with alumina and dimethicone (Silicone) 60^a (56.2)^b	UV TITAN M212	Rutile
NM-104	20	Hydrophilic Coated with alumina and glycerol 60^a (46.0)^b	UV TITAN M262	Rutile
NM-105	22	Hydrophilic Not coated 60^a (56.3)^b	TiO₂ P25 Commercial sample, characterized by [38]	Anatase/Rutile 80%/20%

PPD: Primary particle diameter; Specific surface^a given by producer^b analysis by Fraunhofer IKTS, Dresden, Germany
Dimethicone = PDMS. The chemical formula for PDMS is CH₃[Si(CH₃)₂O]_nSi(CH₃)₃, where n is the number of repeating monomer [SiO(CH₃)₂] units. Industrial synthesis can begin from dimethylchlorosilane and water via the following net reaction: n Si(CH₃)₂Cl₂ + n H₂O → [Si(CH₃)₂O]_n + 2n HCl
NM-103 and NM-104 underwent surface finishing with alumina. For NM-103, a polysiloxane polymer layer is also involved. The overall surface treatment mass was approximately 2% each. For details, see [38]

ISSN: 1743-8977