scholarly journals Facile aqueous, room temperature preparation of high transverse relaxivity clustered iron oxide nanoparticles

Author(s):  
Nicholas J. Hobson ◽  
Xian Weng ◽  
Marianne Ashford ◽  
Nguyen T.K. Thanh ◽  
Andreas G. Schätzlein ◽  
...  
2009 ◽  
Vol 152-153 ◽  
pp. 205-208 ◽  
Author(s):  
H. Arabi ◽  
S. Nateghi ◽  
S. Sadeghi

Iron oxide nanoparticles were synthesis by reverse micelle method. X-ray diffraction technique and vibration sample magnetometer were applied to characterize the produced samples at different conditions and parameters for synthesis route. There is no significant difference between samples prepared at 5°C and room temperature except a better crystalline at room temperature. The molar ratio of water to surfactant (w parameter) and concentration of the salt solution on size and magnetic properties of nanoparticles have been investigated. Increasing w leads to producing particles with larger size i.e. for w=16.83, 11.22, and 5.6, particles size are 15.22, 11.66 and 10.5 nm, respectively. The size of nanoparticles are in the range of 9 to 20 nanometers


2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
P. Burnham ◽  
N. Dollahon ◽  
C. H. Li ◽  
A. J. Viescas ◽  
G. C. Papaefthymiou

Comparative studies are presented of iron oxide nanoparticles in the 7–15 nm average diameter range ball milled in hexane in the presence of oleic acid. Transmission electron microscopy identified spherical particles of decreasing size as milling time and/or surfactant concentration increased. Micromagnetic characterization via Mössbauer spectroscopy at room temperature yielded broadened magnetic spectroscopic signatures, while macromagnetic characterization via vibrating sample magnetometry of 7-8 nm diameter particles showed largely superparamagnetic behavior at room temperature and hysteretic at 2 K. Zero-field and field-cooled magnetization curves exhibited a broad maximum at ~215 K indicating the presence of strong interparticle magnetic interactions. The specific absorption rates of ferrofluids based on these nanoparticle preparations were measured in order to test their efficacies as hyperthermia agents.


2004 ◽  
Vol 43 (45) ◽  
pp. 6135-6139 ◽  
Author(s):  
Rie Mikami ◽  
Minori Taguchi ◽  
Koji Yamada ◽  
Koji Suzuki ◽  
Osamu Sato ◽  
...  

2015 ◽  
Vol 15 (5) ◽  
pp. 3870-3878 ◽  
Author(s):  
S. Vikram ◽  
M. Dhakshnamoorthy ◽  
R. Vasanthakumari ◽  
A. R. Rajamani ◽  
Murali Rangarajan ◽  
...  

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Alina Mihaela Prodan ◽  
Simona Liliana Iconaru ◽  
Carmen Mariana Chifiriuc ◽  
Coralia Bleotu ◽  
Carmen Steluta Ciobanu ◽  
...  

The aim of this study was to provide information about the biological properties of iron oxide nanoparticles (IO-NPs) obtained in an aqueous suspension. The IO-NPs were characterized by transmission electron microscopy (TEM). Analysis of hysteresis loops data at room temperature for magnetic IO-NPs sample indicated that the IO-NPs were superparamagnetic at room temperature. The calculated saturation magnetization for magnetic iron oxide wasMs= 18.1 emu/g. The antimicrobial activity of the obtained PMC-NPs was tested against Gram-negative (Pseudomonas aeruginosa1397,Escherichia coliATCC 25922), Gram-positive (Enterococcus faecalisATCC 29212,Bacillus subtilisIC 12488) bacterial as well as fungal (Candida krusei963) strains. The obtained results suggested that the antimicrobial activity of IO-NPs is dependent on the metallic ions concentrations and on the microbial growth state, either planktonic or adherent. The obtained IO-NPs exhibited no cytotoxic effect on HeLa cells at the active antimicrobial concentrations.


2014 ◽  
Vol 79 (9) ◽  
pp. 1155-1167 ◽  
Author(s):  
Natasa Jovic ◽  
Maria Calatayud ◽  
Beatriz Sanz ◽  
Amelia Montone ◽  
Gerardo Goya

Hybrid structures composed of exfoliated expanded graphite (EG) and iron oxide nanocrystals have been produced by an ex situ process. The iron oxide nanoparticles coated with meso-2,3-dimercaptosuccinic acid (DMSA), or poly(acrylic) acid (PAA) were integrated onto the exfoliated EG flakes by mixing their aqueous suspensions at room temperature under support of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) and N-hydroxysuccin-nimide (NHS). EG flakes have been used both, naked and functionalized with branched polyethylenimine (PEI). Complete integration of two constituents has been achieved and mainteined stable for more than 12 months. No preferential spatial distribution of anchoring sites for attachement of iron oxide nanoparticles has been observed, regardless EG flakes have been used naked or functionalized with PEI molecules. The structural and physico-chemical characteristics of the exfoliated expanded graphite and its hybrids nanostructures has been investigated by SEM, TEM, FTIR and Raman techniques.


2014 ◽  
Vol 5 ◽  
pp. 1472-1476 ◽  
Author(s):  
Bashiru Kayode Sodipo ◽  
Azlan Abdul Aziz

We report a sonochemical method of functionalizing superparamagnetic iron oxide nanoparticles (SPION) with (3-aminopropyl)triethoxysilane (APTES). Mechanical stirring, localized hot spots and other unique conditions generated by an acoustic cavitation (sonochemical) process were found to induce a rapid silanization reaction between SPION and APTES. FTIR, XPS and XRD measurements were used to demonstrate the grafting of APTES on SPION. Compared to what was reported in literature, the results showed that the silanization reaction time was greatly minimized. More importantly, the product displayed superparamagnetic behaviour at room temperature with a more than 20% higher saturation magnetization.


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