Preparation of Silica-Coated Lanthanum-Strontium Manganite Particles with Designable Curie Point, for Application in Hyperthermia Treatments

Silica-coated lanthanum–strontium manganite particles with La0.76Sr0.24MnO3+δ stoichiometric formula, exhibiting Curie temperature at ∼40°C, were prepared by using a traditional solid-state method of synthesis of magnetic ceramic particles, followed by milling and a low-temperature coating procedure in an aqueous alcoholic alkali medium. The properties of the obtained material establish it as a potential candidate for self-regulated power-absorbing and temperature-controlling materials in hyperthermia treatments. Moreover, core-comprising LaSr–manganites with different stoichiometries, ranging from La0.5Sr0.5MnO3+δ to LaMnO3+δ, were synthesized, with magnetic and structural properties examined thereof. Herein reported findings can potentially be used in the preparation of silica-coated magnetic particles with designable Curie temperature, offering a wide range of possibilities of adapting the material to practical instrumental setups in drug delivery and hyperthermia treatments

Sinteza mikrokompozitnih kroglic z magnetnimi nanodelci v porozni matriki CaCO[spodaj]3

A method for synthesis of soft magnetic microbeads is presented. The microbeads are made from magnetic nanoparticles dispersed in CaCO3 (calcium carbonate) matrix. The composite beads are almost perfectly spherical with a diameter of few micrometers. The majority of the composite beads consists of a porous CaCO3 matrix. Magnetic nanoparticles with a size of about 10-15 nm are made of Fe2O3. They are captured inside the pores of CaCO3 matrix during its formation. CaCO3 matrix is formed by crystallization from saturated solution of sodium carbonate and calcium chloride. The composite beads are coated with a layer of functionalized polymer. The magnetic microbeads were characterized by SEM and XPS. Different functional groups were detected by XPS measurements including SO3–,NH3+,NH2,CO32– and OH groups. The results indicate that the iron oxide particles are absent on the surface and that the polymer coating serves as a good biocompatible film.V tem prispevku predstavljamo metodo za sintezo delcev, ki so sestavljeni iz kompozita magnetnih nanodelcev v matrici iz kalcijevega karbonata (CaCO3). Velikost kompozitnih delcev, ki so popolnoma sferične oblike, je nekaj mikrometrov. Ključni del ogrodja kompozitnega delca sestavlja zelo porozna matrica CaCO3. Magnetni nanodelci velikosti približno 10-15 nm so narejeni iz Fe2O3. Ti nanodelci se med tvorjenjem matrice CaCO3 ujamejo v notranjost por. CaCO3 matrica se tvori pri kristalizaciji nasičene raztopine natrijevega karbonata in kalcijevega klorida. Tako nastali kompozit je nato oplaščen še s plastjo funkcionaliziranega polimera. Sintetizirane magnetne kompozitne delce smo analizirali z metodama SEM in XPS. Kot je razvidno iz XPS meritev, je prišlo na površini do nastanka različnih funkcionalnih skupin kot so SO3–,NH3+,NH2,CO32– in OH skupine. Rezultati dokazujejo, da na površini mikrodelcev ne najdemo nanodelcev, ki so skriti znotraj por, ter da lahko polimerna prevleka, ki prekriva mikrodelce, služi kot dobra biokompatibilna podlaga za nadaljnjo vezavo bioloških substanc

Silica-Coated Lanthanum-Strontium Manganites for Hyperthermia Treatments

La0.76Sr0.24MnO3 + δ particles, prepared by performing a traditional, solid-state method of synthesis, were coated by uniform layers of silica via initiating hydrolysis and condensation of TEOS in aqueous–alcoholic alkali environment. The eventually obtained samples exhibited Curie temperature at ∼40 °C, and comprised core-shell particles of ∼250 nm in diameter. By varying stoichiometric ratio of cations within manganite cores of the particles, Curie point of the resulting material can be varied too, thus opening a way for the simple design of biocompatible, temperature-self-regulating particles for application in hyperthermia treatments, with Curie point thereof adjusted to a destined biological context of application

Effects and risks of nanotechnologies and nanomaterials on environment and human health

Razvoj nanomaterialov in njihova uporaba v tekstilstvu sta velika priložnost za izdelavo novih izdelkov z različnimi funkcionalnimi in tehnološkimi lastnostmi, vendar razvoj poleg priložnosti pomeni tveganja za okolje in zdravje ljudi v obliki nanoonesnaževanja ter toksičnih vplivov na žive organizme. V prispevku so obravnavani okoljski vplivi in zdravstvena tveganja nanomaterialov, ki se najpogosteje uporabljajo v tekstilstvu, kot npr. nanodelci srebra ($Ag$), silicijevega dioksida ($SiO_2$), titanovega dioksida ($TiO_2$), cinkovega oksida ($ZnO$), aluminijevega oksida ($Al_2O_3$), aktivnega oglja, nanoglina in ogljikove nanocevke (CNT).Development of nanomaterials and their use in the textile field is opening new opportunities for products with special functional and technological featureshowever, there is also expressed concern over the environmental and human health aspects of nanomaterials. This paper discusses the environmental impacts and health risks of nanomaterials commonly used in textiles, e.g. silver nanoparticles ($Ag$), silica nanoparticles ($SiO_2$), titanium dioxide nanoparticles ($TiO_2$), zinc oxide nanoparticles ($ZnO$), nanoparticles of aluminum oxide ($Al_2O_3$), carbon-black nanoparticles, montmorillonite and carbon nanotubes (CNT)

Nanomaterials for functional textiles

Napredni funkcionalni nanomateriali so z razvojem nanotehnologije postali bistven sestavni del industrijskih materialov in s tem osnova gospodarskih dejavnosti, kjer sta zahtevani inovativnost in visoka dodana vrednost proizvodov. Razvoj visokofunkcionalnih nanomaterialov je moč an vir potencialnih inovacij in napredka, posebno v tekstilni industriji, ki le tako lahko ohrani primat v Zahodni Evropi in svetu. Tako je razvoj funkcionalnih tekstilij z vgrajenimi naprednimi visokofunkcionalnimi nanomateriali pomembna tržna niša z veliko vgrajenega znanja in uporabo sodobnih tehnologij. Vgradnja visokofunkcionalnih nanomaterialov v tekstilne izdelke in oblačila daje tekstilijam nove želene specifične funkcionalne lastnosti, ki lahko poveč ajo udobnost in kakovost življenja, varnost in omogočijo lažji nadzor zdravja. Čeprav napredni visokofunkcionalni nanomateriali dajejo tekstilnim izdelkom nove funkcije, se morajo pri tem ohraniti vse bistvene lastnosti tekstilije, kot so nosljivost, upogibljivost, mehkost, elastič nost, lahkost, pralnost itd. Danes se v tekstilni industriji uporabljajo predvsem visokofunkcionalni anorganski in polimerni nanodelci, nanonanostrukturni materiali, nanokompoziti in nanovlakna za doseganje funkcionalnih lastnosti, kot so antistatične, protimikrobne, samočistilne in ojačitvene. V tem prispevku bomo podrobneje predstavili nanomateriale, ki se najpogosteje uporabljajo za razvoj funkcionalnih tekstilij s poudarkom na hidrofobnih, superhidrofobnih in hidrofilnih lastnostih tekstilij z izboljšanimi možnostmi obarvanja ter s povečano odpornostjo na bledenje barv, UV zaščitnih in ognjevarnih tekstilij.In the last decade, the advancement of nanotechnology and its application in several areas has been encouraging the global competition, and many industries need innovative solutions in order to provide better performance and enhanced value to their products. The development of high-functional nanomaterials represents a powerful source of potential innovation and progress in the European textile industry, which can only compete with the rest of the world with the products with added value. The development of functional and smart textiles with built-in advanced high-functional nanomaterials presents an important market niche with a high amount of built-in knowledge and use of modern technologies. The use of high-functional nanomaterials in textiles gives the new desired specific functional properties that can enhance the comfort and quality of life, safety, and can ease the control of health. Despite the fact that advanced high-functional nano-textile products give new functions, they shall keep all the essential features of textiles, such as wearability, flexibility, softness, elasticity, lightness, washability etc. Today, the textile industry mainly uses high-functional inorganic and polymeric nanoparticles, nanostructured materials, nanocomposites and nanofibres to achieve the functional properties such as antistatic, antimicrobial, self-cleaning, reinforcement etc. In this paper, we present in detail the nanomaterials that are most commonly used for the development of functional textiles with the emphasis on hydrophobic and hydrophilic properties, textiles with improved colouring and with increased resistance to colour fading, textiles used for UV-protection and fire-resistant textiles

Terbium Ion Adsorption from Aqueous Solution by Using Magnetic γ-Fe₂O₃-NH₄OH@SiO₂ Nanoparticles Functionalized with Amino Groups

New magnetic stabilized and functionalized core@shell nanoparticles (NPs) were synthesized in a simple way and characterized in order to adsorb Tb3+ from aqueous solution with a very low Tb3+ concentration. For the fluorescence determination of adsorption efficiency and capacity, tiron monohydrate as a ligand was used. The obtained results confirm the potential of the synthesized magnetic γ-Fe2O3-NH4OH@SiO2 NPs, functionalized with (3-Aminopropyl) trimethoxysilane (APTMS), to be used for adsorption of Tb3+ from aqueous solution, with the possibility of its removal from aqueous solution via an external magnet. The endothermic and spontaneous adsorption follows a pseudo-second-order kinetic model, and the adsorption equilibrium data fit the Temkin isotherm well. The maximum adsorption efficiency from aqueous solution with a 2 × 10−6 M concentration of Tb3+ is over 90% at pH 7

Lead (II) complexation with 3-mercaptopropyl-groups in the surface layer of silica nanoparticles: Sorption, kinetics and EXAFS/XANES study

In this work, mono-dispersed mercapto-functionalized silica (SiO$_2$@SH) particles with a narrowparticle size distributionof around (420±10) nmwere prepared by the sol–gel method for the adsorption of aqueous dissolvedlead (Pb$^{2+}$) ions from modeled wastewater. Transmission Electron Microscopy (TEM), in combination with Energy-Dispersive X-ray Spectroscopy (EDXS), was used to obtain information about the particle size and morphologyof the prepared samples. Dispersive X-ray Spectroscopy (EDXS) indicated strong signals of Si and S, implyingsuccessful completion after the mercapto (-SH) functionalization of the silica (SiO$_{2}$) surfaces. Fourier TransformInfrared Spectroscopy (FTIR) was used to determine the occurrences of Si–O–Si and -SH vibrations within thesamples and, thus, come to a conclusion about the formations of the mercapto-functionalized samples. Analysiswas performed of Pb$^{2+}$ adsorption with mercapto-groups (-SH) on the surface of the SiO$_{2}$@SH particles. The resultsfor Pb$^{2+}$ adsorptions fromthemodeledwastewater showed affinity of around 55% and the obtained value ofthe maximum amount of adsorbed Pb$^{2+}$ ions with the SiO$_{2}$@SH samples was 10.82 mg/g under the conditionsused during this study. The results of the adsorptions were fitted with the Langmuir and Freundlich isothermmodels and the pseudo-first and pseudo-second kinetic models were evaluated. We employed Pb-L3 edge Xrayabsorption spectroscopy techniques XANES (X-ray Absorption Near Edge Structure) and EXAFS (ExtendedX-ray Absorption Fine Structure) for probing the local environments of Pb within the tentative Pb-S complexafter adsorptions of Pb$^{2+}$ by the mercapto groups. The EXAFS/XANES analysis indicated complete Pb$^{2+}$ complexationwith two -SH groups of the prepared SiO$_{2}$@SH samples