Halloysite and Laponite Hybrid Pigments Synthesis with Copper Chlorophyll

Sustainable and green materials have been studied in dye and pigment productions to reduce their environment impacts from being produced and applied. Although natural dyes are an excellent choice to move from agrowaste, some improvements must be made before they are applied given their poor fastness. One way of improving natural dye properties is their adsorption into nanoclay structures to give hybrid pigments. This work used tubular halloysite and laminar laponite to adsorb and stabilize natural copper chlorophyll. With a statistical design of experiments, we observed interactions between synthesis factors, such as pH, ionic strength, and surfactant or silane modification. Cool hybrid pigments with high TSR (%) values and a wide color range were obtained by using dispersions with only distilled water at room temperature. Successful chlorophyll adsorption on both nanoclay surfaces took place by XRD and DTA analyses. The maximum natural dye absorption for both nanoclay types took place under acid conditions, pH 3–4, and in the presence of mordant. The TSR (%) improved by the silane pH interaction, and halloysite hybrid pigments obtained higher TSR values than the laponite ones. Finally, a wide chromatic green color range was obtained with the surfactant modification in both nanoclays, and the color fastening was also improved in the hybrid pigments application. The samples generated with 10% of hybrid pigments from both nanoclays and an Epoxy bioresin, show higher colorfastness than the sample with the natural chlorophyll, due to the nanoclays–dye interaction and protection.

Removal of Carbamazepine onto Modified Zeolitic Tuff in Different Water Matrices: Batch and Continuous Flow Experiments

Carbamazepine (CBZ) is the most frequently detected pharmaceutical residues in aquatic environments effluent by wastewater treatment plants. Batch and column experiments were conducted to evaluate the removal of CBZ from ultra-pure water and wastewater treatment plant (WWTP) effluent using raw zeolitic tuff (RZT) and surfactant modified zeolite (SMZ). Point zero net charge (pHpzc), X-ray diffraction (XRD), X-ray fluorescence (XRF), and Fourier Transform Infrared (FTIR) were investigated for adsorbents to evaluate the physiochemical changes resulted from the modification process using Hexadecyltrimethylammonium bromide (HDTMA-Br). XRD and FTIR showed that the surfactant modification of RZT has created an amorphous surface with new alkyl groups on the surface. The pHpzc was determined to be approximately 7.9 for RZT and SMZ. The results indicated that the CBZ uptake by SMZ is higher than RZT in all sorption tests (>8 fold). Batch results showed that the sorption capacity of RZT and SMZ in WWTP effluent (0.029 and 0.25 mg/g) is higher than RZT and SMZ (0.018 and 0.14 mg/g) in ultrapure water (1.6–1.8 fold). Batch tests showed that the equilibrium time of CBZ removal in the WWTP matrix (47 h) is much longer than CBZ removal in ultrapure water. The sorption capacity of RZT & SMZ in WWTP effluent (0.03, 0.33 mg/g) is higher than RZT and SMZ (0.02 and 0.17 mg/g) in ultrapure water (1.5–2 fold) using column test. This study has clearly demonstrated that the performance of RZT and SMZ is more efficient for the removal of CBZ from realistic wastewater than ultrapure water. It is evident that the surfactant modification of RZT has enhanced the CBZ removal in both matrices.

Influence of diazonium and surfactant modification of the mesoporous material on its adsorption properties

We describe a new and direct route to obtain Al-SBA-15-modified materials with different groups on their surface using diazonium salts. For comparison, modification using surfactants was also used. In the present study, we decided to examine the applicability of these materials in the adsorption of compounds released from dental fillings. The effectiveness of modification was proved by results of Fourier transform infrared spectroscopy and energy-dispersive spectrometry. The results indicate the formation of characteristic groups on the surface of the materials. The materials after modification are characterized by smaller surface area and pore volume, which is result of covering the surface with an aryl or surfactant layer. The adsorption properties change after modification and depend on the used modifier. Diazonium modification has a positive effect on sorptive properties when hydroxyl and dimethylamine groups are obtained. The methods of material modification presented in this work may in the future lead to the improvement in the properties of sorbents used in solid-phase extraction.