pH-responsive carboxymethyl cellulose conjugated superparamagnetic iron oxide nanocarriers

In the present study, polyethyleneimine (PEI) coated superparamagnetic iron oxide nanoparticles (SPIONs) having the size of 15 nm in diameter with high magnetic saturation (60 emu/g) have been prepared by co-precipitation method. The synthesized PEI-Fe3O4 nanoparticles have been fully characterized by transmission electron microscope (TEM), dynamic light scattering (DLS), Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) techniques. The free amine groups on the PEI-Fe3O4 surface has been covalently functionalized with carboxymethyl cellulose (CMC) by the catalysis of N,N'-Dicyclohexylcarbodiimide (DCC) and N, N'-Dimethylpyridin-4-amine (DMAP) coupling to produce CMC-Fe3O4 nanocarriers. The prepared CMC-Fe3O4 nanocarriers have been loaded with a well-known anti-tumor drug doxorubicin (Dox) and investigated its loading and releasing profiles from the nanocarrier. The CMC acted as an excellent nanocarrier for Dox with a loading efficiency ≈ 86%. The drug releasing profile has been studied at different pH values (3.5; 5.5; and 7.4). When the pH of the release medium (phosphate buffer solution) was changed from 7.4 to 5.5 or 3.6, the drug release has been increased which indicates that the drug releasing is pH dependent.No sponso

Poboljšanje kvalitete smolom impregniranog papira za pokrivni sloj laminata

This study aimed to improve the quality properties of impregnated papers used as a coating material in wood-based composites, especially for high-density fiberboard (HDF) floorings, using the Taguchi method and parameter design. Three factors were evaluated in determining the interactions as they are considered the most important in affecting the product quality characteristics such as particle size of Al2O3, surface modification agent and melamine raw material. Experiments were conducted in three replications using the L18 (21 × 32) orthogonal array. Color and gloss measurements were evaluated together with the sensory analysis method, which takes into account the number of the spots in the sample as quality characteristics. The best values obtained as a result of statistical analysis were A2 for the melamine raw material, 30 to 60 μm for the particle size and N-methyl-3-(trimethoxysilyl) propylamine for the surface modifier agent. Whether the experimental factors have a meaningful effect on the quality characteristics was also tested separately by analysis of variance. Only 58 % of the effect of the evaluated factors on the outcome could be expressed with the linear model (R2adj = 0.5785).Cilj ovog istraživanja bio je poboljšati kvalitetu impregniranih papira koji se upotrebljavaju kao prekrivni materijal za drvne kompozite, posebice za podove od tvrde ploče vlaknatice (HDF) primjenom Taguchijeve metode i projektiranja parametara. Za proučavanje interakcija odabrana su tri čimbenika za koja se smatra da najviše utječu na kvalitetu proizvoda. To su veličina čestica Al2O3, sredstvo za modifikaciju površine i melamin. Eksperimenti su provedeni na tri identična uzorka primjenom ortogonalnog niza L18 (21 × 32). Rezultati boje i sjaja proučavani su zajedno metodom senzorske analize, koja kao odrednicu kvalitete uzima u obzir broj točaka na uzorku. Statistički najbolji rezultati dobiveni su za melamin A2, veličinu čestica 30 do 60 mm i za sredstvo za modifikaciju površine Nmetil-3-(trimetoksilil) propilamin. Također, analizom varijance testirana je smislenost učinka eksperimentalnih čimbenika na kvalitetu papira. Samo 58 % evaluiranih čimbenika moglo se izraziti linearnim modelom (R2adj = 0,5785)