Effect of ageing process on crystal morphology of Co-Mg-Al hydrotalcite

The Optimal Concentration of Nanoclay Hydrotalcite for Recovery of Reactive and Direct Textile Colorants

“…The peak shown at 1496 cm −1 is characteristic of the azo bond [ 60 ]. Other peaks are observed in Samples 4 and 9 at 1600 and 1630 cm −1 , respectively, which correspond to the aromatic groups -C=C- [ 55 , 56 , 57 , 58 ], in the colorant the peak is at 1618 cm −1 .…”

“…At this point, it is worth noting that hydrotalcite has a crystalline structure [ 55 , 56 ] and colorants an amorphous form. The peak of the XRD is higher when more crystalline structures are present, but this structure is totally lost when the H is calcined to form HC;it is recovered to a large extent when it is hydrated again.…”

“…In the case of Direct Blue 199 ( Figure 13 ) and Direct Blue 71 ( Figure 14 ), the peak at 1100 cm −1 is attributed to acetates, formates, propionates, and benzoates [ 59 ]. Previous work has indicated that the peaks between 1400 and 1640 cm −1 [ 55 , 56 , 57 , 58 ] correspond to benzene rings and that the peak shown at 1500 cm −1 is characteristic of the azo bond [ 60 ] which in Sample 12 can be seen smoothly shifted to 1520 cm −1 . Another peak can be found at 1035 cm −1 which corresponds to the symmetric sulfonate vibration [ 48 ].…”

Complete Desorption of Hybrid Nanoclays Composed of Hydrotalcite and Disperse Dye

“…A detailed study of the area around 11° in Figure 8 shows that the crystalline structure of the clay is gradually destroyed by the continuous desorption–dyeing process. Thus, H4DR1 shows a collapse of the clay, which practically loses all its crystallinity, leaving a much more amorphous structure [ 37 , 38 , 39 ].…”

Evaluation of CO2 Adsorption Capacity of Crystalline, Microporous Zeolite-Y Structure

“…The modified catalytic zeolites are characterized by XRD and BET techniques. The XRD and BET techniques are elaborated in our previous publications [14]- [16].…”