Guanidine-functionalized Fe3O4 magnetic nanoparticles as basic recyclable catalysts for biodiesel production

RSC Advances ◽  
2015 ◽  
Vol 5 (59) ◽  
pp. 48031-48038 ◽  
Author(s):  
Evelyn C. S. Santos ◽  
Thiago C. dos Santos ◽  
Renato B. Guimarães ◽  
Lina Ishida ◽  
Rafael S. Freitas ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Magnetic Nanoparticles ◽  
Iron Oxide Nanoparticles ◽  
Biodiesel Production ◽  
Oxide Nanoparticles ◽  
Fe3o4 Magnetic Nanoparticles ◽  
Recyclable Catalysts

Two organic superbases, 1,5,7-triazabicyclo[4,4,0]dec-5-ene (TBD) and 1,1,3,3-tetramethylguanidine (TMG), were anchored onto silica-coated and uncoated iron oxide nanoparticles, resulting in three recoverable basic nanocatalysts.

Evaluation of Surface-modified Superparamagnetic Iron Oxide Nanoparticles to Optimize Bacterial Immobilization for Bio-separation with the Least Inhibitory Effect on Microorganism Activity

2020 ◽  
Vol 10 (2) ◽  
pp. 166-174
Author(s):  
Mehdi Khoshneviszadeh ◽  
Sarah Zargarnezhad ◽  
Younes Ghasemi ◽  
Ahmad Gholami
Keyword(s):  
Iron Oxide ◽  
Amino Acid ◽  
Magnetic Nanoparticles ◽  
Iron Oxide Nanoparticles ◽  
Surface Coating ◽  
Superparamagnetic Iron Oxide ◽  
Superparamagnetic Iron Oxide Nanoparticles ◽  
Oxide Nanoparticles ◽  
Surface Charges ◽  
Surface Modified

Background: Magnetic cell immobilization has been introduced as a novel, facile and highly efficient approach for cell separation. A stable attachment between bacterial cell wall with superparamagnetic iron oxide nanoparticles (SPIONs) would enable the microorganisms to be affected by an outer magnetic field. At high concentrations, SPIONs produce reactive oxygen species in cytoplasm, which induce apoptosis or necrosis in microorganisms. Choosing a proper surface coating could cover the defects and increase the efficiency. Methods: In this study, asparagine, APTES, lipo-amino acid and PEG surface modified SPIONs was synthesized by co-precipitation method and characterized by FTIR, TEM, VSM, XRD, DLS techniques. Then, their protective effects against four Gram-positive and Gram-negative bacterial strains including Enterococcus faecalis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa were examined through microdilution broth and compared to naked SPION. Results: The evaluation of characterization results showed that functionalization of magnetic nanoparticles could change their MS value, size and surface charges. Also, the microbial analysis revealed that lipo-amino acid coated magnetic nanoparticles has the least adverse effect on microbial strain among tested SPIONs. Conclusion: This study showed lipo-amino acid could be considered as the most protective and even promotive surface coating, which is explained by its optimizing effect on cell penetration and negligible reductive effects on magnetic properties of SPIONs. lipo-amino acid coated magnetic nanoparticles could be used in microbial biotechnology and industrial microbiology.

Effect of aluminum doped iron oxide nanoparticles on magnetic properties of the polyacrylonitrile nanofibers

2017 ◽  
Vol 37 (2) ◽  
pp. 135-141
Author(s):  
Armin Ourang ◽  
Soheil Pilehvar ◽  
Mehrzad Mortezaei ◽  
Roya Damircheli
Keyword(s):  
Magnetic Properties ◽  
Iron Oxide ◽  
Magnetic Nanoparticles ◽  
Iron Oxide Nanoparticles ◽  
Oxide Nanoparticles ◽  
Negative Interaction ◽  
Magnetic Nanofibers

Abstract In this work, polyacrylonitrile (PAN) was electrospun with and without magnetic nanoparticles (aluminum doped iron oxide) and was turned into magnetic nanofibers. The results showed that nanofibers diameter decreased from 700 nm to 300 nm by adding nanoparticles. Furthermore, pure PAN nanofibers were indicated to have low magnetic ability due to polar bonds that exist in their acrylonitrile groups. Obviously by adding only 4 wt% of the nanoparticles to PAN nanofibers, magnetic ability soared by more than 10 times, but at a higher percentage, it was shown to change just a little due to negative interaction among nanoparticles. This event relates to antiferromagnetically coupling of nanoparticles due to incomplete dispersion at higher percentage.

The Effect of Focused Ultrasound on Magnetic Polyelectrolyte Capsules Loaded with Dye When Suspended in Tissue-Mimicking Gel

2019 ◽  
Vol 16 (4) ◽  
pp. 355-363 ◽  
Author(s):  
Carmen Stavarache ◽  
Mircea Vinatoru ◽  
Timothy Mason
Keyword(s):  
Iron Oxide ◽  
Magnetic Nanoparticles ◽  
Iron Oxide Nanoparticles ◽  
Exposure Time ◽  
Ultrasonic Irradiation ◽  
Focused Ultrasound ◽  
Relative Degree ◽  
Oxide Nanoparticles ◽  
Dye Release ◽  
Iron Oxide Magnetic Nanoparticles

Background: Capsules containing a dye were prepared by the LbL method with iron oxide nanoparticles (50 nm) in different layers of the shell. Method: The capsules were dispersed in a gel and subjected to focused ultrasonic irradiation at three different powers and exposure times. Result: It was found that the inclusion of iron oxide magnetic nanoparticles in any of the polyelectrolyte shells (4, 6, 8 and 10) strengthened the capsules with respect to capsules without nanoparticles. Incorporation of nanoparticles in shell 8 provided the most resistance to fragmentation under focused ultrasonic irradiation. The relative degree of capsule stability is dependent on both the power of the ultrasound and the exposure time. Conclusion: The presence of iron oxide nanoparticles not only conferred more resistance to fragmentation but also provided a route to protein labelled dye release through sonoporation that was not present for capsules without nanoparticles.

scholarly journals Micromixer Synthesis Platform for a Tuneable Production of Magnetic Single-Core Iron Oxide Nanoparticles

Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1845
Author(s):  
Abdulkader Baki ◽  
Norbert Löwa ◽  
Amani Remmo ◽  
Frank Wiekhorst ◽  
Regina Bleul
Keyword(s):  
Iron Oxide ◽  
Magnetic Nanoparticles ◽  
Iron Oxide Nanoparticles ◽  
Magnetic Particle ◽  
Biomedical Application ◽  
Ac Susceptibility ◽  
Chemical Properties ◽  
Oxide Nanoparticles ◽  
Aqueous Synthesis ◽  
Characterization Methods

Micromixer technology is a novel approach to manufacture magnetic single-core iron oxide nanoparticles that offer huge potential for biomedical applications. This platform allows a continuous, scalable, and highly controllable synthesis of magnetic nanoparticles with biocompatible educts via aqueous synthesis route. Since each biomedical application requires specific physical and chemical properties, a comprehensive understanding of the synthesis mechanisms is not only mandatory to control the size and shape of desired nanoparticle systems but, above all, to obtain the envisaged magnetic particle characteristics. The accurate process control of the micromixer technology can be maintained by adjusting two parameters: the synthesis temperature and the residence time. To this end, we performed a systematic variation of these two control parameters synthesizing magnetic nanoparticle systems, which were analyzed afterward by structural (transmission electron microscopy and differential sedimentation centrifugation) and, especially, magnetic characterization methods (magnetic particle spectroscopy and AC susceptibility). Furthermore, we investigated the reproducibility of the microtechnological nanoparticle manufacturing process compared to batch preparation. Our characterization demonstrated the high magnetic quality of single-core iron oxide nanoparticles with core diameters in the range of 20 nm to 40 nm synthesized by micromixer technology. Moreover, we demonstrated the high capability of a newly developed benchtop magnetic particle spectroscopy device that directly monitored the magnetic properties of the magnetic nanoparticles with the highest sensitivity and millisecond temporal resolution during continuous micromixer synthesis.

Chemically tunable cationic polymer-bonded magnetic nanoparticles for gene magnetofection

2014 ◽  
Vol 2 (6) ◽  
pp. 644-650 ◽  
Author(s):  
Makoto Takafuji ◽  
Kumiko Kitaura ◽  
Takuro Nishiyama ◽  
Srinath Govindarajan ◽  
Vijaya Gopal ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Magnetic Nanoparticles ◽  
Iron Oxide Nanoparticles ◽  
Viral Vectors ◽  
Cationic Polymer ◽  
Oxide Nanoparticles ◽  
Super Paramagnetic Iron Oxide

This study evaluates the efficiency of novel non-viral vectors consisting of super paramagnetic iron oxide nanoparticles functionalized with the chemically tunable cationic polymer forin vitrogene magnetofection.

Folic acid conjugated magnetic iron oxide nanoparticles for nondestructive separation and detection of ovarian cancer cells from whole blood

2016 ◽  
Vol 4 (1) ◽  
pp. 159-166 ◽  
Author(s):  
Wenting Liu ◽  
Liju Nie ◽  
Fulai Li ◽  
Zoraida P. Aguilar ◽  
Hong Xu ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Folic Acid ◽  
Iron Oxide ◽  
Magnetic Nanoparticles ◽  
Cancer Cells ◽  
Iron Oxide Nanoparticles ◽  
Whole Blood ◽  
Ovarian Cancer Cells ◽  
Oxide Nanoparticles ◽  
Magnetic Iron Oxide Nanoparticles

An effective method for separation and detection of ovarian cancer cells from whole blood using folic acid conjugated magnetic nanoparticles.

scholarly journals Iron Oxide Nanoparticles for Magnetic Hyperthermia

SPIN ◽  
2019 ◽  
Vol 09 (02) ◽  
pp. 1940001 ◽  
Author(s):  
N. A. Usov
Keyword(s):  
Magnetic Field ◽  
Iron Oxide ◽  
Magnetic Nanoparticles ◽  
Iron Oxide Nanoparticles ◽  
Stochastic Equation ◽  
Sharp Decrease ◽  
Dipole Interaction ◽  
Magnetic Hyperthermia ◽  
Alternating Magnetic Field ◽  
Oxide Nanoparticles

Assemblies of magnetic nanoparticles show a great potential for application in biomedicine, particularly, magnetic hyperthermia. However, to achieve desired therapeutic effect in magnetic hyperthermia, the assembly of nanoparticles should have a sufficiently high specific absorption rate (SAR) in alternating magnetic field of moderate amplitude and frequency. Using the Landau–Lifshitz stochastic equation, it is shown that dilute assemblies of iron oxide nanoparticles of optimal diameters are capable of providing SAR of the order of 400–600[Formula: see text]W/g in alternating magnetic field with the amplitude [Formula: see text][Formula: see text]Oe in the frequency range f = 300–500[Formula: see text]kHz. Unfortunately, in dense clusters of magnetic nanoparticles, which are often formed in a biological medium, there is a sharp decrease in SAR due to the influence of strong magneto-dipole interaction of closest nanoparticles. To overcome this difficulty, it is suggested covering the nanoparticles with nonmagnetic shells of sufficient thickness or using non-single-domain nanoparticles being in magnetization curling states.

Surface active magnetic iron oxide nanoparticles for extracting metal nanoparticles across an aqueous–organic interface

2019 ◽  
Vol 7 (34) ◽  
pp. 10623-10634 ◽  
Author(s):  
Meenakshi Verma ◽  
Kultar Singh ◽  
Mandeep Singh Bakshi
Keyword(s):  
Iron Oxide ◽  
Magnetic Nanoparticles ◽  
Metal Nanoparticles ◽  
Iron Oxide Nanoparticles ◽  
Gemini Surfactants ◽  
Oxide Nanoparticles ◽  
Magnetic Iron Oxide Nanoparticles ◽  
Magnetic Iron Oxide ◽  
Surface Active

Highly surface active magnetic nanoparticles (Fe3O4 NPs) were synthesized by using tetraalkylammonium and imidazolium Gemini surfactants.

scholarly journals Nanocomposites comprised of homogeneously dispersed magnetic iron-oxide nanoparticles and poly(methyl methacrylate)

2018 ◽  
Vol 9 ◽  
pp. 1613-1622 ◽  
Author(s):  
Sašo Gyergyek ◽  
David Pahovnik ◽  
Ema Žagar ◽  
Alenka Mertelj ◽  
Rok Kostanjšek ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Magnetic Nanoparticles ◽  
Methyl Methacrylate ◽  
Iron Oxide Nanoparticles ◽  
Oxide Nanoparticles ◽  
Magnetic Iron Oxide Nanoparticles ◽  
Uniform Loading ◽  
Magnetic Iron Oxide ◽  
Induced Hyperthermia ◽  
Pmma Matrix

Nanocomposites with a high, uniform loading of magnetic nanoparticles are very desirable for applications such as electromagnetic shielding and cancer treatment based on magnetically induced hyperthermia. In this study, a simple and scalable route for preparing nanocomposites with a high, uniform loading of magnetic nanoparticles is presented. The magnetic iron-oxide nanoparticles were functionalized with a methacrylate-based monomer that copolymerized in a toluene solution with the methyl methacrylate (MMA) monomer. The resulting suspension of magnetic nanoparticles decorated with poly(methyl methacrylate) (PMMA) chains in toluene were colloidal, even in the presence of a magnetic field gradient. Nanocomposites were precipitated from these suspensions. The transmission electron microscopy investigation of the prepared nanocomposites revealed that the magnetic nanoparticles were homogeneously dispersed in the PMMA matrix, even in amounts up to 53 wt %. The uniform dispersion of the nanoparticles in the PMMA matrix was attributed to the good solvation of the grafted PMMA chains from the magnetic nanoparticles by the PMMA chains of the matrix. The nanocomposites were superparamagnetic and exhibited large values for the saturation magnetization of up to 36 emu/g. Moreover, the nanocomposite with the largest amount of incorporated nanoparticles exhibited relatively large values for the specific power loss when subjected to alternating magnetic fields, giving this material great potential for the magnetically induced hyperthermia-based treatment of cancer.

Metalla-aromatic loaded magnetic nanoparticles for MRI/photoacoustic imaging-guided cancer phototherapy

2018 ◽  
Vol 6 (17) ◽  
pp. 2528-2535 ◽  
Author(s):  
Caixia Yang ◽  
Gan Lin ◽  
Congqing Zhu ◽  
Xin Pang ◽  
Yang Zhang ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Magnetic Nanoparticles ◽  
Cancer Therapy ◽  
Iron Oxide Nanoparticles ◽  
Photoacoustic Imaging ◽  
Superparamagnetic Iron Oxide ◽  
Superparamagnetic Iron Oxide Nanoparticles ◽  
Oxide Nanoparticles

In this study, metalla-aromatic agents and a cluster of superparamagnetic iron oxide nanoparticles were loaded inside a micellar carrier and used for MRI/PA imaging-guided PTT/PDT synergistic cancer therapy.

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