A new material, graphene oxide/polypyrrole (GO/Ppy), was synthesized by mixing graphene oxide and polypyrrole in a specific proportion. It possesses a unique structure similar to that of foam. A homemade pipette-tip solid-phase extraction (PT-SPE) device, which is more simple and convenient than traditional devices, was used for saving reagents and operation time. When GO/Ppy was used as the adsorbent of PT-SPE for determining three auxins (indole-3-propionic acid, indole-3-butyric acid, and 1-naphthaleneacetic acid) present in trace amounts in papaya juice, it showed high affinity and adsorption capacity for all the three auxins. GO/Ppy-PT-SPE also had a significant capacity for eliminating the interferences from the papaya juice matrix. Under optimized conditions, a good linearity of auxins was obtained in the range 16.3–812.5 ng g −1 ; the average recoveries at the three spiked levels of the three auxins ranged from 89.4% to 105.6% with the relative standard deviations ≤3.0%. Meanwhile, six papaya juice samples with different growth stages were analyzed under optimum conditions, and trace auxins in the range 18.3–100.6 ng g −1 were observed. Because of its high selectivity, simplicity, and reliability, the GO/Ppy-PT-SPE method developed herein can be potentially applied for determining trace auxins in complex biological samples.
In polar environments, the presence of ice on the surfaces of ships and instruments can lead to equipment failure, an unstable center of gravity, and pose hazards to operators. To mitigate the damage caused by both icing and corrosion, this paper aims to investigate a corrosion-resistant photothermal deicing coating material. The coating matrix utilizes a low-viscosity epoxy resin system, while the additives include polypyrrole (PPy) with excellent photothermal conversion capability and corrosion resistance, along with graphene oxide (GO)-modified nano-silica. By carefully controlling the ratio, a composite coating is formulated with both anti-corrosion and photothermal deicing abilities under light conditions. The results demonstrate that under simulated sunlight irradiation, the surface temperature of the coating at different proportions can rise to over 80 ℃ within 10 min, with the highest temperature reaching 84.9 ℃. The optimal proportion of the coating remains unfrozen at -15 ℃, exhibiting an icing delay time of 710 s, and the frozen droplets melt within 5 s. Additionally, the coating exhibits excellent corrosion resistance, contributing to a more effective protection of metal surfaces. Therefore, this type of photothermal anticorrosive coating holds significant potential for widespread application in polar environments.
危险品化学品经营许可证（带存储）