Oleic acid coating on the monodisperse magnetite nanoparticles

Zhang, Ling; He, Rong; Gu, Hongchen

doi:10.1016/j.apsusc.2006.05.023

Cited by 900 publications

(656 citation statements)

References 27 publications

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“…After complete aggregation of the building blocks at higher temperatures and longer times, the amount of desorption significantly decreased. Some researchers explained that the TGA behaviors are based on the bi-layer adsorbed models on the particle surface [45,46], while others claimed that the double-stepped TGA curve is due to two different kinds of binding sites [47,48]. Based on experimental results, it seems that the TGA curves for our samples are in agreement with the two different binding sites on the surface of the nanoparticles.…”

Section: Analysis Of Tgasupporting

confidence: 51%

Role of polymeric surfactants on the growth of manganese ferrite nanoparticles

Bastami

Entezari

et al. 2012

Chemical Engineering Journal

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Section: Analysis Of Tgasupporting

confidence: 51%

Role of polymeric surfactants on the growth of manganese ferrite nanoparticles

Bastami

Entezari

et al. 2012

Chemical Engineering Journal

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“…Two new bands, at 1580 and 1410 cm −1 , which are characteristic of the asymmetric ν as (COO − ) and the symmetric ν s (COO − ) stretches of the carboxylate group, 58,59 are instead present.…”

Section: ■ Experimental Sectionmentioning

confidence: 96%

Spectroscopic and Theoretical Study of the Grafting Modes of Phosphonic Acids on ZnO Nanorods

et al. 2013

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Metal oxides are versatile substrates for the design of a wide range of SAM-based organic−inorganic materials among which ZnO nanostructures modified with phosphonic SAM are promising semiconducting systems for applications in technological fields such as biosensing, photonics, and field-effect transistors (FET). Despite previous studies reported on various successful grafting approaches, issues regarding preferred anchoring modes of phosphonic acids and the role of a second reactive group (i.e., a carboxylic group) are still a matter of controversial interpretations. This paper reports on an experimental and theoretical study on the functionalization of ZnO nanorods with monofunctional alkylphosphonic and bifunctional carboxyalkylphosphonic acids. X-ray photoelectron and infrared spectroscopies have been combined with DFT modeling to explain and understand the interactions that drive the surface anchoring of phosphonic acids on ZnO surface. It was found that both monofunctional and bifunctional acids anchor on ZnO through a multidentate bonding which involves both PO and P−O moieties of the phosphonic group. Moreover, anchored bifunctional acids bend to the surface, promoting a further interaction between surface hydroxyl groups and carboxylic terminations. This secondary interaction can be limited by increasing the surface density of the anchored molecules. ■ INTRODUCTIONFunctionalization of metal oxides with self-assembled monolayers (SAMs) is nowadays a field of great interest since it is a powerful and low-cost method to form stable and flexible surfaces with controlled properties. 1−3 Possible applications range from protective coatings which enhance mechanical properties (such as adhesion, friction, and corrosion resistance) 4−6 to functional layers in specific electronics devices such as field-effect transistors, 7,8 sensors, 9−12 or dye-sensitized solar cells (DSSCs). 13 Therefore, the present decade has seen a surge of interest in the modification of metal oxides (TiO 2 , AgO, Al 2 O 3 , ZrO, ZnO, ITO) with SAM having various anchoring groups, among which phosphonic moieties were proven to be an efficient alternative to the more often adopted carboxylic and siloxane tethering functionalities. 14−17 Among mentioned metal oxides, nanostructured ZnO, a wide-band-gap semiconductor (E g = 3.37 eV at room temperature) 18 used in sensors, 19 electronic devices, 20,21 and solar cells, 22−24 is a promising substrate for the design of SAM-based organic− inorganic materials of technological relevance. 25−32 Examples of SAM-functionalized ZnO nanostructures include nanorods modified either with carboxyalkylphosphonic acids (HOOC-(CH 2 ) n P(O)(OH) 2 (n = 2, 9)) for biosensing 25 or with C60-functionalized phosphonic linkers for photonic devices 26 and nanowire-based ZnO field-effect transistors (FET) which use long-chain alkylphosphonic acids as gate dielectrics. 27 Despite various studies reported on a wide range of successful anchoring approaches, issues regarding preferred anchoring modes (monodenta...

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“…The intense peak at 1710 cm −1 (oleic acid molecule) is derived from the existence of the C=O stretch, and the band at 1285 cm −1 exhibits the presence of the C-O stretch. The O-H in-plane and outof-plane bands appear at 1462 cm −1 and 937 cm −1 , respectively [27][28][29][30][31]. A set of bands appear at 1381 and 848 cm −1 , which are attributed to the N-O stretching and bending vibrations of NO − 3 , respectively [32][33][34].…”

Section: Sem Analysismentioning

confidence: 97%

The Effect of Condensation on the Morphology and Magnetic Properties of Modified Barium Hexaferrite (BaFe12O19)

et al. 2011

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Abstract:We present a comparison for the effect of condensation on the morphology and magnetic properties of oleic acid modified BaFe12O19 nanoparticles. Two different samples of BaFe12O19 nanoparticles were synthesized by dehydration (Z1) and rotary evaporation (Z2) method, respectively. Oleic acid was used as the surface modification agent to observe the morphological and magnetic changes. The nanoparticles were analyzed by XRD, FTIR, TGA, SEM, and VSM techniques for structural and physicochemical characteristics. Crystallographic analysis reveals the phase as hexaferrite and the average crystallite size of Z1 and Z2 is 21±3 nm and 17±2 nm, respectively. Rotary evaporator accelerates the condensation process in viscous gel (Z2). Due to the use of rotary evaporator, the coating with oleic acid for Z2 product has been accomplished very well, as compared with Z1. As a result, saturation magnetization of Z2 sample is much lower than that of Z1 sample.

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Oleic acid coating on the monodisperse magnetite nanoparticles

Cited by 900 publications

References 27 publications

Role of polymeric surfactants on the growth of manganese ferrite nanoparticles

Role of polymeric surfactants on the growth of manganese ferrite nanoparticles

Spectroscopic and Theoretical Study of the Grafting Modes of Phosphonic Acids on ZnO Nanorods

The Effect of Condensation on the Morphology and Magnetic Properties of Modified Barium Hexaferrite (BaFe12O19)

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