Kontrollált stabilitású polimer nano- és biokompozitok kifejlesztése és ellenőrzött gyártástechnológiája = Development of polymer nano- and biocomposites of designed stability and controlled technology for their production

A projekt megvalósítása során új nano- és biostruktúrákat (nano-antacid, bio/szénnanoszál) állítottunk elő, melyek hatóanyag-hordozóként, segédanyagként alkalmazhatók. Hatóanyagok morfológiáját (pl. amorfizálás) segédanyagok jelenlétében szabályoztuk. Korszerű (részben újonnan kifejlesztett) analitikai és matematikai (kemometria, kvantumkémiai) módszerekkel segítettük elő a fáziskölcsönhatások/felületmódosítások hatásának megértését. Így optimális technológiákat és receptúrákat választhattunk ki égésgátló hatású (pl. foszforszármazékok, nanorészecskék) és gyógyszer (pl. antacid, diuretikum, béta-blokkoló és Alzhimer-kór ellenes) hatóanyagok formulálására. Szabályozott mini/szuperkritikus-extrúzióval terjesztettük ki ezeket az eredményeket (a jól biohasznosuló) amorf gyógyszer-készítmények stabilitásának biztosítására. Kontrollált electrospinning technikával előállított nanoszálakal egy évet meghaladó stabilitást bizonyítottuk. Nanostruktúrált nedvességzáró bevonatok kifejlesztésével hidrolízis-érzékeny hatóanyagok stabilitását sikerült megőrizni. Az alkalmazástechnikai lehetőségek biogyógyszerészeti és égésgátlási irányba is bővültek (pl. probiotikum nanoformulálása, önkioltó PP és TP-PUR előállítása). Az ipari léptékű kontrollált gyártás előkészítésére in-line analitikai módszerek, szabályozott reaktor és extrúder alkalmazásával megnövelt léptékű kísérletekre került sor. Az eredményeket 51 közlemény, 2 szabadalom, PhD, OTDK, TDK dolgozatok formájában dokumentáltuk. | The realization of the project resulted in preparation of new nano/biostructures (nano-antacide, bio/carbonfiber), which can be applied as drug delivery and auxiliary additives. The morphology of active ingredients (amorpization) was controlled in presence of excipients. We promoted the understanding of the influences of interfacial interactions and surface modifications by modern/new analytical and mathematical (chemometry, quantum chemistry) methods. Thus optimal technologies and recipes could be chosen for formulation of active flame retardant (phosphorous derivatives, nanoparticles) and pharmaceutical (antacid, diuretic, beta-blocker and anti-Alzhimer- disease) ingredients. We extended these results to the stabilization of amorphous pharmaceuticals of good bioavailability by controlled mini/supercritical extrusion. In the case of nanofibers prepared by controlled electrospinning more than one year stability could be proven. The stability of hydrolysis-sensitive actives could be preserved by developing nanostructured humidity-barrier coating. The applicability of the results could be extended to biopharmacy and fire safety (nanoformulation of probiotics, preparation of self-extinguishing PP and TP-PUR) direction. In order to prepare the industrial scale production we applied in-line analytical methods, controlled reactor and extruder at larger scale experiments. We documented the results in 51 scientific papers, 2 patent claims, PhD theses, OTDK, TDK reports

Decoration of Vertically Aligned Carbon Nanotubes with Semiconductor Nanoparticles Using Atomic Layer Deposition

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Flame retardancy of microcellular poly(lactic acid) foams prepared by supercritical CO2-assisted extrusion

Flame-retardant-treated cellulose (FR-cell) was used as bio-based charring agent in combination with ammonium polyphosphate (APP) based intumescent flame retardant (IFR) system to reduce the flammability of poly(lactic acid) (PLA) foams produced by supercritical carbon dioxide (sc-CO2) assisted extrusion. FR-cell was obtained by surface treatment of cellulose with diammonium phosphate (DAP) and boric acid (BA). To enhance foamability, the inherently low melt strength and slow crystallization rate of PLA was increased by adding epoxy-based chain extender (CE) and montmorillonite (MMT) nanoclay, respectively. The morphology of the foams was examined using water displacement method, scanning electron microscopy (SEM) and energy dispersive X-ray spectrometry (EDS). Thermal properties were assessed using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Flammability was evaluated by limiting oxygen index (LOI) measurements, UL-94 tests and pyrolysis combustion flow calorimetry (PCFC). The continuous extrusion foaming technique allowed the preparation of low density PLA foams with uniform microcellular structure and void fractions higher than 90% accompanied with increased crystallinity of up to 19%. Despite the high expansion ratios (i.e. high surface area), the PLA foams showed excellent flame retardancy, UL-94 V-0 rate and LOI value of 31.5 vol% was achieved with an additive content as small as 19.5%. However, the flame retardant synergism evinced between IFR and MMT proved to be less pronounced in the expanded foams compared to bulk materials with identical additive contents

Effect of pH in the hydrothermal preparation of monoclinic tungsten oxide

This paper presents the preparation of monoclinic WO3 by a one-step hydrothermal method. The effect of very acidic pH (0.1) and the significance of various additives (CH3COOH, NaClO4, Na2SO4) were investigated. To clarify the role of pH on the obtained crystal structure and morphology, every synthesis using pH 1 were repeated, and the effect of temperature, using 180 and 200 °C, was also studied. All samples prepared at pH 0.1 were pure, well crystallized monoclinic WO3 independently from the temperature, the presence and the quality of the additives. At 180 and 200 °C, applying CH3COOH and NaClO4 resulted nanosheets similar in size. With Na2SO4 additive at 180 °C sheets, at 200 °C sheets and also rods formed indicating that SO4 2− was a capping agent only at 200 °C. For comparison, at pH 1 at both temperatures the crystalline phases and the morphologies varied depending on the type of the additive. © 2019 The Author

Preparation and characterization of a nitrogen-doped mesoporous carbon aerogel and its polymer precursor

Nitrogen-containing carbon aerogel was prepared from resorcinol–melamine–formaldehyde (R–M–F) polymer gel precursor. The polymer gel was supercritically dried with CO2, and the carbonization of the resulting polymer aerogel under nitrogen atmosphere at 900 °C yielded the carbon aerogel. The polymer and carbon aerogels were characterized with TG/DTA–MS, low-temperature nitrogen adsorption/desorption (− 196 °C), FTIR, Raman, powder XRD and SEM–EDX techniques. The thermal decomposition of the polymer aerogel had two major steps. The first step was at 150 °C, where the unreacted monomers and the residual solvent were released, and the second one at 300 °C, where the species belonging to the polymer network decomposition could be detected. The pyrolytic conversion of the polymer aerogel was successful, as 0.89 at.% nitrogen was retained in the carbon matrix. The nitrogen-doped carbon aerogel was amorphous and possessed a hierarchical porous structure. It had a significant specific surface area (890 m2 g−1) and pore volume (4.7 cm3 g−1). TG/DTA–MS measurement revealed that during storage in ambient conditions surface functional groups formed, which were released upon annealing