title: Synthesis of Non-Toxic Silica Particles Stabilized by Molecular Complex Oleic-Acid/Sodium Oleate.
abstract: The present work is focused on the preparation of biocompatible silica particles from sodium silicate, stabilized by a vesicular system containing oleic acid (OLA) and its alkaline salt (OLANa). Silica nanoparticles were generated by the partial neutralization of oleic acid (OLA), with the sodium cation present in the aqueous solutions of sodium silicate. At the molar ratio OLA/Na⁺ = 2:1, the molar ratio (OLA/OLANa = 1:1) required to form vesicles, in which the carboxyl and carboxylate groups have equal concentrations, was achieved. In order to obtain hydrophobically modified silica particles, octadecyltriethoxysilane (ODTES) was added in a sodium silicate sol-gel mixture at different molar ratios. The interactions between the octadecyl groups from the modified silica and the oleyl chains from the OLA/OLANa stabilizing system were investigated via simultaneous thermogravimetry (TG) and differential scanning calorimetry (DSC) (TG-DSC) analyses.A significant decrease in vaporization enthalpy and an increase in amount of ODTES were observed. Additionally, that the hydrophobic interaction between OLA and ODTES has a strong impact on the hybrids' final morphology and on their textural characteristics was revealed. The highest hydrodynamic average diameter and the most negative ζ potential were recorded for the hybrid in which the ODTES/sodium silicate molar ratio was 1:5. The obtained mesoporous silica particles, stabilized by the OLA/OLANa vesicular system, may find application as carriers for hydrophobic bioactive molecules.
authors.affiliation: National Research & Development Institute for Chemistry and Petrochemistry-ICECHIM, Spl. Independentei 202, 6th District, Bucharest 060021, Romania. catalin.spataru@icechim-pd.ro.
authors.forename: Catalin Ilie
authors.initials: CI
authors.lastname: Spataru
authors.affiliation: National Research & Development Institute for Chemistry and Petrochemistry-ICECHIM, Spl. Independentei 202, 6th District, Bucharest 060021, Romania. raluca.ianchis@icechim-pd.ro.
authors.forename: Raluca
authors.initials: R
authors.lastname: Ianchis
authors.affiliation: National Research & Development Institute for Chemistry and Petrochemistry-ICECHIM, Spl. Independentei 202, 6th District, Bucharest 060021, Romania. cristian.petcu@icechim-pd.ro.
authors.forename: Cristian
authors.initials: C
authors.lastname: Petcu
authors.affiliation: National Research & Development Institute for Chemistry and Petrochemistry-ICECHIM, Spl. Independentei 202, 6th District, Bucharest 060021, Romania. cristina.nistor@icechim-pd.ro.
authors.forename: Cristina Lavinia
authors.initials: CL
authors.lastname: Nistor
authors.affiliation: National Research & Development Institute for Chemistry and Petrochemistry-ICECHIM, Spl. Independentei 202, 6th District, Bucharest 060021, Romania. violeta.purcar@icechim-pd.ro.
authors.forename: Violeta
authors.initials: V
authors.lastname: Purcar
authors.affiliation: National Research & Development Institute for Chemistry and Petrochemistry-ICECHIM, Spl. Independentei 202, 6th District, Bucharest 060021, Romania. trica.bogdan@gmail.com.
authors.forename: Bogdan
authors.initials: B
authors.lastname: Trica
authors.affiliation: National Research & Development Institute for Chemistry and Petrochemistry-ICECHIM, Spl. Independentei 202, 6th District, Bucharest 060021, Romania. sabina.nitu@icechim-pd.ro.
authors.forename: Sabina Georgiana
authors.initials: SG
authors.lastname: Nitu
authors.affiliation: National Research & Development Institute for Chemistry and Petrochemistry-ICECHIM, Spl. Independentei 202, 6th District, Bucharest 060021, Romania. raluca.somoghi@icechim-pd.ro.
authors.forename: Raluca
authors.initials: R
authors.lastname: Somoghi
authors.affiliation: National Research & Development Institute for Chemistry and Petrochemistry-ICECHIM, Spl. Independentei 202, 6th District, Bucharest 060021, Romania. elvira.alexandrescu@icechim-pd.ro.
authors.forename: Elvira
authors.initials: E
authors.lastname: Alexandrescu
authors.affiliation: National Research & Development Institute for Chemistry and Petrochemistry-ICECHIM, Spl. Independentei 202, 6th District, Bucharest 060021, Romania. florinoancea07@gmail.com.
authors.forename: Florin
authors.initials: F
authors.lastname: Oancea
authors.affiliation: National Research & Development Institute for Chemistry and Petrochemistry-ICECHIM, Spl. Independentei 202, 6th District, Bucharest 060021, Romania. ddonescu@chimfiz.icf.ro.
authors.forename: Dan
authors.initials: D
authors.lastname: Donescu
mesh_terms: D000468:Alkalies / Q000737:chemistry; D001672:Biocompatible Materials / Q000138:chemical synthesis*; D002414:Cations, Monovalent; D003692:Delayed-Action Preparations / Q000138:chemical synthesis*; D057927:Hydrophobic and Hydrophilic Interactions; D019301:Oleic Acid / Q000737:chemistry*; D044367:Phase Transition; D012821:Silanes / Q000737:chemistry; D017640:Silicates / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*; D012964:Sodium / Q000737:chemistry; D013816:Thermodynamics
chemical_list: D000468:Alkalies; D001672:Biocompatible Materials; D002414:Cations, Monovalent; D003692:Delayed-Action Preparations; D012821:Silanes; D017640:Silicates; D019301:Oleic Acid; D012822:Silicon Dioxide; D012964:Sodium; C005691:sodium silicate
keywords: mesoporous silica; octadecyltriethoxysilane; oleic acid; sodium silicate