Effects Of Suspensions With Different Properties And Structures On Suspension And Adsorption Properties Of Carbon

As one of the important engineering nanomaterials, carbon nanotubes (CNTs) is widely used in the production and life of human beings due to its unique physical and chemical properties, such as mechanical strength, conductivity, hydrogen storage capacity and so on. With the increasing application, the CNTs are inevitably discharged into the environment and caused an unpredictable influence on environment.. Many previous studies focused on the effects of dissolved organic matter (DOM) on the environmental behavior and risk of CNTs. It was found that DOM could make CNTs dispersed, causing strong interactions between CNTs and pollutants via exposing greater surface area. Owing to the nanometer scale, suspended CNTs may carry pollutants directly into the organism causing biological toxicity. Additionally, the environmental risk of suspended CNTs and the adsorbed organic pollutant by CNTs also exacerbated due to the great mobility. However, researchers did not pay enough attention to the suspension mechanisms of CNTs suspended by different properties and structures suspending agents There is little research on the adsorption characteristics of pollutants on suspended CNTs under different suspension mechanisms. Therefore, this study selected tannic acid (TA), gallic acid (GA) and sodium dodecylbenzenesulfonate (SDBS) presented three different properties and structures suspending agents, researched the adsorption behaviour of different properties and structures suspending agents on CNTs, clarified the mechanism of different properties and structures suspending agents dispersed CNTs. Bisphenol A (BPA) was selected as pollutants. The adsorption capacity of CNTs suspended by different properties and structures suspending agentswas researched. The results are obtained as follows:1. Before the concentrations of three suspending agents reached the the critical micelle concentration (CMC) of TA and SDBS, the order of suspended CNTs followed:TA> SDBS> GA. Combined with the adsorption amounts of TA, SDBS and GA these three suspending agents on the CNTs, it found that the property and structure suspending agent is the most important factor for controlling CNTs suspended. Even though the adsorbed amounts of suspending agent on the CNTs will also affect the suspension of CNTs. Therefore, the adsorption of TA, SDBS and GA on the CNTs caused by the combined effects of all kinds of mechanisms, of which the most important controlling factors is the steric hindrance, also including hydrophobic interactions, π-π interactions, hydrogen bonding and so on. The effect of steric hindrance is the most important mechanism to control the suspension of CNTs by TA, SDBS and GA.2. This study found that the amount of BPA that adsorbed on CNTs that suspended by TA, SDBS and GA these three suspending agents is opposite to the order of the steric effect caused by TA, SDBS and GA these three suspending agents that adsorbed on CNTs. In addition, combined with the adsorption mechanism of BPA on CNTs that suspended by TA, SDBS and GA these three suspending agents, it could conclude that the steric hindrance is the main effect of controlling BPA adsorption on CNTs. In addition, the adsorption of BPA on the surface of the suspended CNTs increased due to the solubilization effect of suspending gents that adsorbed on CNTs for BPA above CMC.