Hyperthermic Agent Prepared by One-Pot Modification of Maghemite Using an Aliphatic Polyester Model

et al. 2021

Geopolymers are materials composed of aluminosilicates, which upon activation by the alkaline solution, form repeating units, being classified as inorganic polymers. Geopolymers have gained prominence due to obtaining the raw material that can be natural or residual, the ease of production, and cost-effective. These materials are widely used in civil construction for the replacement of Portland cement and also in the environmental area for the remediation of toxic compounds. However, there is a lack in the literature about the applications of these materials. Thus, this work deals with geopolymers for the sorption of hydrogen sulfide gas.

Section: Introductionmentioning

confidence: 99%

Geopolymer Microparticles as Up‐and‐Coming H₂S Sorbers

Maranhão¹,

Almeida²,

et al. 2021

“…[ 28–33 ] Among the last three, polymers are vital materials for the Humankind and have been widely researched by Biopolymers and Sensors Lab Group from UFRJ. [ 34–145 ]…”

Section: Introductionmentioning

confidence: 99%

Novel Core‐Shell System Based on Gelatin and Hydrophilic Polymers Useful as Concrete Self‐healing Systems

Costa

Sousa

et al. 2021

Concrete structures repair results in substantial economic and environmental issues. So, new technologies able to increase concrete lifetime are being developed. Among them, the self-healing mechanisms, which can be improved by using polymers. Thus, three different materials are synthesized to act as self-healing systems. They are: (I) cross-linked gelatin mixed with CaCO 3 (the self-healing agent); (II) a core-shell system based on the material I layered by poly(hydroxypropyl methacrylate); and (III) a second core-shell structure based on the material I covered with poly(vinyl alcohol). Cross-linking and grafting are performed using glutaraldehyde. Fourier-transform infrared spectroscopy (FTIR) proves the structure obtaining. Thermogravimetric analysis and differential scanning calorimetry prove that the materials show thermal properties that allow their use in concrete applications. Swelling degree shows that all materials swell when in contact with water. Granulometry shows the materials are mostly in the millimeter scale. Last, an aqueous media release test shows that the three tested systems did not liberate significant amounts of CaCO 3 . Therefore, both the gelatin and gelatin + polymer systems can protect the healing material, avoiding the release of the self-healing agent before the concrete cracking takes place.

“…Magnetic nanoparticles are widely used in a myriad of applications. [ 1–35 ] Among the leading applications are controlled drug delivery, [ 36,37 ] Magnetic resonance imaging, [ 38 ] magnetohyperthermia, [ 39,40 ] cell separation [ 41 ] and tissue repairing. [ 42 ] For their use as medicines, nanoparticles must be biocompatible and have toxic action only on the tissue of interest.…”

Section: Introductionmentioning

confidence: 99%

Surface Modification of Magnetite with PBS Using a Ricinoleic‐Toluene Diisocyanate Fragment as the Binder Structure

Moraes

Sáez

et al. 2021

Magnetite nanoparticles are widely used in current medicine because their magnetite properties allow several uses as drug delivery systems, contrasts in imaging tests, and even for magnetohyperthermia. However, magnetic nanoparticles possess meager Zeta potential, presenting a strong tendency to agglomerate. For clinical use, they must be covered with a biocompatible material to maintain colloidal stability, without, however, altering its magnetic properties. Thus, for biomedical applications in general, magnetic nanocomposites are more interesting than pure magnetite. The present work applies poly(butylene succinate) (PBS), as a coating on magnetite nanoparticles, aiming to increase their biocompatibility. PBS is a polymer obtained from renewable sources, being entirely suitable for pharmacological uses. In this work, the synthesis of ricinoleic acid from natural castor oil is carried out through the saponification method and subsequent acid hydrolysis. In turn, the synthesis of magnetite nanoparticles is performed by coprecipitation. Then, by an acid-base reaction, the nanoparticles are treated with ricinoleic acid. Soon afterward, toluene diisocyanate is used to produce bonding between the modified particles and PBS. Fourier-transform infrared spectroscopy confirms the synthesis of the material. Also, scanning electron microscopy and dynamic light scattering experiments are performed. The obtained results allow inferring the success in the preparation of the pursued hybrid material.