The colloidal stability and core-shell structure of magnetite nanoparticles coated with alginate

The surface of the magnetite nanoparticles has been engineered by the proteins available in the leaf extract of Datura inoxia. Fourier Transform Infrared (FTIR) study and by thermo gravimetric analysis (TGA) confirms the bonding between metal ions and the amide carbonyl group preset in the plant protein confirming the formation of core-shell structure. The plant protein coated magnetic Fe3O4 nanoparticles under investigation have an average size of about 14 nm (˂20nm). The isothermal magnetization curve of the ferrofluid appears in S-like sigmoid shape showing soft nonhysteretic magnetic behaviour at room temperature. The saturation magnetization (MS), remanent magnetization (MR), squareness (MR/MS) and coercivity value (HC) increased with decreasing temperature from 300 K to 10 K. The increment of magnetization (45 to 53 emu/gm) might be due to the decrease in thermal energy while the enhancement of coercivity (0-208 Oe) is attributed to the exchange interaction at the interface between the ferromagnetic (Fe3O4) and diamagnetic surface layer of protein on the nanocrystalline magnetite. The magnetization value is much smaller in comparison with the bulk magnetite (92emu/g) due to surface spin disorder also approves core-shell structure of diamagnetic protein layer on the surface. The results show the ease of the synthesis to reinforce the colloidal stability where the super paramagnetic behaviour has been found to be restored. The core-shell moiety could play an important role in biological systems as a means of storing Fe+3 for an organism.

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Multifunctional Polymeric Nanogels for Biomedical Applications

Gels ◽

10.3390/gels7040228 ◽

2021 ◽

Vol 7 (4) ◽

pp. 228

Author(s):

Tisana Kaewruethai ◽

Chavee Laomeephol ◽

Yue Pan ◽

Jittima Amie Luckanagul

Keyword(s):

Drug Delivery ◽

Delivery System ◽

Shell Structure ◽

Biomedical Applications ◽

Colloidal Stability ◽

Functionalized Polymers ◽

Core Shell ◽

Structural Components ◽

Bioactive Substances ◽

Core Shell Structure

Currently, research in nanoparticles as a drug delivery system has broadened to include their use as a delivery system for bioactive substances and a diagnostic or theranostic system. Nanogels, nanoparticles containing a high amount of water, have gained attention due to their advantages of colloidal stability, core-shell structure, and adjustable structural components. These advantages provide the potential to design and fabricate multifunctional nanosystems for various biomedical applications. Modified or functionalized polymers and some metals are components that markedly enhance the features of the nanogels, such as tunable amphiphilicity, biocompatibility, stimuli-responsiveness, or sensing moieties, leading to specificity, stability, and tracking abilities. Here, we review the diverse designs of core-shell structure nanogels along with studies on the fabrication and demonstration of the responsiveness of nanogels to different stimuli, temperature, pH, reductive environment, or radiation. Furthermore, additional biomedical applications are presented to illustrate the versatility of the nanogels.

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Synthesis, characterization and adsorption capacity of lead(II) ions of Fe3O4/C core-shell structure materials

Vietnam Journal of Catalysis and Adsorption ◽

10.51316/jca.2021.026 ◽

2021 ◽

Vol 10 (2) ◽

pp. 43-48

Author(s):

Dang Le Hai ◽

Trang Luu Thu ◽

Hoang Tran Vinh ◽

Doanh Vu Viet ◽

Thu Le Dieu ◽

...

Keyword(s):

Aqueous Solution ◽

Magnetite Nanoparticles ◽

Shell Structure ◽

Adsorption Process ◽

Langmuir Model ◽

Core Shell ◽

Order Model ◽

Pseudo Second Order ◽

Core Shell Structure ◽

Model Expression

Core shell magnetite nanoparticles (Fe3O4@C) as adsorbent for lead ions from aqueous solution were synthesized. The characteristics of the modified materials were analysed. It could also be shown that the adsorption isotherms were well described by the Langmuir model. The kinetic of the adsorption process was found to follow the pseudo-second-order model expression. Thermodynamic studies indicated that the adsorption process was feasible, spontaneous and endothermic.

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