Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China.
Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China.
Sci Total Environ. 2016 Feb 15;544:134-42. doi: 10.1016/j.scitotenv.2015.11.157. Epub 2015 Dec 3.
Despite extensive research demonstrating the influence of organic matter and inorganic phosphate on the stability of TiO2 nanoparticles (NPs), far less research has assessed the impact of myo-inositol hexakisphosphate (IHP), a common organic phosphate widely present in the environment. In this study, the adsorption of IHP on TiO2 NPs and its impact on their colloidal stability were investigated using batch experiments, dynamic light scattering (DLS) techniques, in situ attenuated total reflectance Fourier transform infrared (ATR-FTIR) and solid-state (31)P nuclear magnetic resonance (NMR) spectroscopy. Inorganic orthophosphate (Pi) adsorption was run for comparison. The ratio of the Pi/IHP adsorption density (1.528: 0.453) at pH5.0 suggested that IHP may complex on the TiO2 surface through three of its six phosphate groups. Zeta potential measurements, ATR-FTIR and NMR spectra indicated that IHP/Pi adsorbed onto TiO2 NPs by forming inner-sphere complexes and modified the surface charge of these NPs, which exerted a great impact on their colloidal stability. Interactions between NPs measured by sedimentation and aggregation size highly depended on the pH, surface phosphorus coverage, and surface phosphorus species. The impact of IHP on the aggregation and dispersion of TiO2 NPs was significantly larger than that of Pi, in agreement with the calculation from the DLVO theory. This study highlighted the impact of IHP relative to Pi on the colloidal stability of TiO2 NPs in phosphorus-enriched environments.
尽管有大量研究表明有机物和无机磷酸盐会影响 TiO2 纳米颗粒（NPs）的稳定性，但对于肌醇六磷酸（IHP）的影响研究却很少，而肌醇六磷酸是一种常见的有机磷酸盐，广泛存在于环境中。在这项研究中，采用批实验、动态光散射（DLS）技术、原位衰减全反射傅里叶变换红外（ATR-FTIR）和固态（31）P 核磁共振（NMR）光谱法研究了 IHP 在 TiO2 NPs 上的吸附及其对胶体稳定性的影响。进行了无机正磷酸盐（Pi）吸附实验作为对比。在 pH5.0 时，Pi/IHP 吸附密度比（1.528:0.453）表明 IHP 可能通过其六个磷酸基团中的三个与 TiO2 表面络合。Zeta 电位测量、ATR-FTIR 和 NMR 谱表明，IHP/Pi 通过形成内球络合物吸附在 TiO2 NPs 上，并改变了这些 NPs 的表面电荷，这对其胶体稳定性产生了重大影响。通过沉降和聚集尺寸测量的 NPs 之间的相互作用强烈依赖于 pH 值、表面磷覆盖率和表面磷物种。与 Pi 相比，IHP 对 TiO2 NPs 聚集和分散的影响要大得多，这与 DLVO 理论的计算结果一致。本研究强调了在富磷环境中，IHP 相对于 Pi 对 TiO2 NPs 胶体稳定性的影响。
