Elias Carvalho Megg Madonyk Cota, Soares Liliane Catone, Adarme Oscar Fernando Herrera, Ferreira Gabriel Max Dias, Savedra Ranylson Marcello Leal, Siqueira Melissa Fabíola, Azevedo Eduardo Ribeiro de, Gurgel Leandro Vinícius Alves
Physical Organic Chemistry Group, Department of Chemistry, Institute of Exact and Biological Sciences, Federal University of Ouro Preto, Campus Morro do Cruzeiro, Rua Quatro, 786, Bauxita, Ouro Preto 35402-136, MG, Brazil.
Interdisciplinary Research Group on Biotechnology Applied to Agriculture and the Environment, School of Agricultural Engineering, University of Campinas, Avenida Cândido Rondon, 501, Campinas 13083-875, SP, Brazil.
Molecules. 2025 Jul 29;30(15):3163. doi: 10.3390/molecules30153163.
A hetero-disubstituted sugarcane bagasse (HDSB) was prepared by simultaneous one-pot chemical modification of sugarcane bagasse with succinic and phthalic anhydrides. HDSB was used in batch mode for the removal of the cationic dyes auramine-O (AO) and safranin-T (ST) from spiked aqueous solutions. Adsorption of the dyes in mono- and bicomponent systems was investigated as a function of HDSB dosage, pH, contact time, and initial dye concentration. Maximum adsorption capacities for AO and ST on HDSB, at pH 7.0, were 1.37 mmol g (367.7 mg g) and 0.93 mmol g (293.3 mg g), respectively. In the bicomponent system, ST was preferentially adsorbed on HDSB, revealing an antagonistic effect of ST on AO adsorption. Changes in the enthalpy of the adsorption as a function of HDSB surface coverage were determined by isothermal titration calorimetry, with Δ° values for AO and ST equal to -22.1 ± 0.3 kJ mol and -23.44 ± 0.01 kJ mol, respectively. Under standard conditions, the adsorption of the dyes on HDSB was exergonic and enthalpically driven. Desorption removed ~50% of the adsorbed dyes, and subsequent re-adsorption showed that HDSB could be reused, with non-desorbed dye molecules acting as new binding sites. The interaction between AO and ST with HDSB was elucidated by molecular dynamics simulations with atomistic modeling.
通过用琥珀酸酐和邻苯二甲酸酐对甘蔗渣进行一锅法同步化学改性制备了一种杂双取代甘蔗渣（HDSB）。HDSB以分批模式用于从加标的水溶液中去除阳离子染料金胺 - O（AO）和番红T（ST）。研究了单组分和双组分体系中染料的吸附情况，考察了HDSB用量、pH值、接触时间和初始染料浓度的影响。在pH 7.0时，HDSB对AO和ST的最大吸附容量分别为1.37 mmol/g（367.7 mg/g）和0.93 mmol/g（293.3 mg/g）。在双组分体系中，ST优先吸附在HDSB上，显示出ST对AO吸附的拮抗作用。通过等温滴定量热法测定了吸附焓随HDSB表面覆盖率的变化，AO和ST的Δ°值分别为-22.1±0.3 kJ/mol和-23.44±0.01 kJ/mol。在标准条件下，染料在HDSB上的吸附是放能的且由焓驱动。解吸去除了约50%的吸附染料，随后的再吸附表明HDSB可以重复使用，未解吸的染料分子充当新的结合位点。通过原子模型的分子动力学模拟阐明了AO和ST与HDSB之间的相互作用。
