Aluminosilicate geopolymers with a high silica molar ratio have been prepared by mixing Croatian coal-ash (ASTM Class F) and sodium silicate solution (water glass, technical grade). The samples were cured at 85 °C for 8 h and 24 h in different experimental conditions. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM/EDS) have been use...

TiO2/SiO2 nanocomposite with molar ratio 1:1 was synthesized by a free calcination sol-gel method using titanium tetra chloride and tetraethylorthosilicate as raw materials. In the composite, TiO2 nanocrystals are highly dispersed in the amorphous SiO2 matrix and the mater showed size quantization effect arising from the presence of extremely small titanium oxide species having a low coordinati...

It is well known that geopolymers are a new group of binder materials alumosilicate origin. Geopolymers made by the reaction precursor aluminosilicate with alkaline activator solutions. The current research relates to low-cost and eco-friendly procedure, suitable being implemented in two easy steps. first step production solid phase based on fly ash (Obrenovac, Serbia) eggshell as waste rich ca...

We describe an Er3+-doped aluminosilicate core photonic crystal fibre laser incorporating distributed Bragg reflectors written by two-photon 193nm irradiation through an optical phase mask as the feedback elements. The laser is diode pumped at 980nm and evidence of dual linewidth laser operation close to threshold is observed. However, at higher pumping levels gain competition preferentially se...

The work presented here was motivated by the premise that the amorphous state serves as a medium to study cocrystal formation. The molecular mobility inherent to amorphous phases can lead to molecular associations between different components such that a single crystalline phase of multiple components or cocrystal is formed. Cocrystallization pathways and kinetics were investigated from amorpho...

The present study investigated aluminosilicate gel in alkali-activated fly ash exposed to a CO₂-rich environment by means of NMR spectroscopy. The alkali-activated fly ash was exposed to an atmospheric CO₂ concentration of 10% after curing at 80 °C initially for 24 h. Under high concentrations of CO₂, highly reactive components Na and Al, which completely reacted within the first few hours, wer...