Acta Chim Slov. 2020 Dec;67(4):1124-1138.
Adsorption of Alizarin Red S (ARS) on graphene oxide/poly(amidoamine) (GO/PAMAM) was studied at different ARS initial concentrations, temperatures, pHs, shaking rates and contact times. Adsorption sites of GO/PAMAM were phenolic -OHgroup of GO and amine groups (-NH2, -NH3+ and -NHR2+) of PAMAM dendrimer moieties of GO/PAMAM. At pH = 2 and 318 K, maximum adsorption capacity of the adsorbent was 1275.2 mg g-1 which is one of the highest capacity in the literature. Thus, GO/PAMAM in this work acted as a superadsorbent for ARS. At the incipient of adsorption, molecules were adsorbed on sites that was reaction-controlled step, (Ea = 114.5 kJ mol-1). Adsorption of on the remaining sites was diffusion-controlled. In alkaline media, two other types of ARS molecules were identified during that were adsorbed on and sites. Further increasing the pH of the solution, decreased the number these two sites and yielded a reduced adsorption capacity . Methylene blue (MB), thionine (Th), pyronin Y (PY), acridine orange (AO), methyl blue (MEB) and janus green (JG) dyes were selectively separated from their mixtures with ARS molecules using GO/PAMAM at pH of 2. The used adsorbent was recycled efficiently by using ethylenediamine very fast.
研究了茜素红 S（ARS）在氧化石墨烯/聚（酰胺-胺）（GO/PAMAM）上的吸附，考察了不同 ARS 初始浓度、温度、pH 值、搅拌速率和接触时间对吸附的影响。GO/PAMAM 的吸附位为 GO 的酚羟基和 GO/PAMAM 中 PAMAM 树枝状大分子的胺基（-NH2、-NH3+ 和 -NHR2+）。在 pH = 2 和 318 K 时，吸附剂的最大吸附容量为 1275.2 mg g-1，这是文献中最高容量之一。因此，GO/PAMAM 在这项工作中充当了 ARS 的超吸附剂。在吸附的初始阶段，分子被吸附在反应控制步骤的位点上（Ea = 114.5 kJ mol-1）。剩余位点上的吸附是扩散控制的。在碱性介质中，在吸附和位点上还鉴定出了另外两种 ARS 分子。进一步提高溶液的 pH 值，减少了这两个位点的数量，导致吸附容量降低。GO/PAMAM 在 pH 值为 2 时可从其与 ARS 分子的混合物中选择性分离亚甲蓝（MB）、硫堇（Th）、吡罗红 Y（PY）、吖啶橙（AO）、甲基蓝（MEB）和詹纳斯绿（JG）染料。用过的吸附剂可用乙二胺快速有效地回收利用。
