▎ 摘　　要

In this work, pH-sensitive hydrogel nanocomposites based on the acrylic acid (AA), graphene oxide (GO) and monoacryloyl tetraammonium thiacalix[4]arene (MATCA) was conveniently prepared via heterogenious copolymerization using methylene bisacrylamide (MBA) and azobisisobutyronitrile (AIBN) as crosslinker and initiator, respectively. The prepared hydrogel nanocomposites showed excellent capability for water absorption up to 67.5 g/g. The pH-sensitive nanocomposite (MATCA-co-AA@GO) with tunable properties was utilized for removing dye pollutant such as malachite green (MG) and methylene blue (MB) dyes from wastewater. The dye removal efficiency up to 95% was achieved at optimum pH of 6.5. FTIR, H-1 and C-13 NMR spectroscopies, CHNSO elemental analysis, mass spectroscopy, TGA, XRD, CHNSO, DMTA and FESEM were used to characterize and study the synthesized materials. In isotherm studies of adsorption, the Freundlich isotherm provided a better fit to the data of MG adsorption. However, in the case of MB, the results are compatible to langmiur isotherm. Results obtained through the kinetic investigations showed that the adsorption of MG and MB on to MATCA-co-AA@GO nanocomposite followed a pseudo-second-order kinetic model. The maximum adsorption capacity (Q(m)) was 67.5 and 70.3 mg g(-1) for MG and MB respectively. Besides, from the thermodynamic data, the adsorption process was suggested to be chemisorption, spontaneous, and endothermic. Reusability of the prepared sorbent was examined by consecutive adsorption/desorption experiments. The prepared adsorbent is recyclable and represents a good candidate for extremely effective sequential removal of MG and MB dyes from wastewater.