Sta 449

The morphology of MIL-101(Cr)@CF was observed by Scanning Electron Microscopy (SEM, Sirion 200 instrument, FEI) equipped with an energy-dispersive X-ray spectrometer (EDS, INCA X-Act attachment, Oxford). The nitrogen adsorption was measured by physisorption apparatus (Autosorb-IQ3, Quantachrome) and the specific surface area is determined by Brunauer-Emmett-Teller (BET) method. The thermal conductivity of MIL-101(Cr)@CF was measured by using laser flash method (LFA 447, Netzsch) and Hot Disk thermal constants analyzer (TPS3500, Hot Disk AB Company, Sweden). The PXRD patterns were measured by an X-ray diffractometer (Ultima IV, Rigaku). FT-IR spectra were measured by an FT-IR spectrometer (Nicolet 6700, Thermo Fisher Scientific). The water sorption isotherms were measured using ASAP analyzer (ASAP2020, Micromeritics) under controllable water vapor pressure. The sample was set at a constant temperature (15, 25, and 35 °C), and the relative pressure of water vapor was increased from 0 to 1 according to pressure intervals. The TGA tests were carried out by thermogravimetric analyzer (STA 449, Netzsch) equipped with a moisture humidity generator (MHG 32, ProUmid).

A simultaneous apparatus for thermogravimetric analysis and differential scanning calorimetry (TG-DSC, STA 449, Netzsch GmbH & Co, Selb, Germany) was applied to quantify the free water content and amount of DCPD in the experimental disks (three specimens per each material). A 5 K/min heating rate under an air atmosphere and a maximum temperature of 1.000 °C were used. Temperatures were recorded and averaged for each material.

To overall evaluate the physicochemical properties of the PET additive, the following tests were adopted: (a) microscopic morphology; surface appearances of waste PET before and after treatment were detected and analyzed by the field-emission scanning electron microscope (ZEISS Gemini SEM 300, Oberkochen, Germany) under vacuum conditions; (b) the molecular structure was characterized by FTIR spectra using the Nicolet Impact 420 FTIR spectrometer (Waltham, MA, USA); (c) the thermal behavior was analyzed by a thermogravimetric analyzer (Netzsch STA 449, Hanau, Germany), and the sample was heated from ambient temperature to 800 °C at a rate of 10 C/min; and (d) the crystalline structure was characterized by X-ray diffraction patterns (from 10° to 80°, Cu-Kαradiation, λ = 1.54 Å) using a D8-Advance powder X-ray diffractometer operating at 40 kV and 30 mA, with a scanning rate of 6°/min and a scanning step of 0.02 (XRD, Bruker AXS, Karlsruhe, Germany).

Nuclear magnetic resonance (NMR) spectra were recorded on a Bruker Avance 400 MHz spectrometer by using CDCl₃ as the solvent and tetramethylsilane (TMS) as the internal standard.
Fourier transform infrared (FTIR) spectra were recorded on a Bruker Tensor 27 spectrometer in the wavenumber range of 400–4000 cm^–1. Samples were ground with KBr and pressed to the plates for measurement.
The particle size, size distribution, and zeta potential were measured by light scattering using Malvern Zetasizer Nano ZS90 system. The diameter of NPs was received from the average of three measurement results.
The morphologies of the nanoparticles were observed by scanning electron microscopy (SEM, Hitachi SU8010) after drying and spraying Pt, and by transmission electron microscopy (TEM, Hitachi 2100) at 100.0 kV.
Thermal gravimetry analysis (TGA) was performed at a heating rate of 10 °C/min under a N₂ atmosphere with a Thermo Gravimetric Analyzer (Netzsch STA 449).
Ultraviolet–visible (UV–vis) absorption spectra mesurements were performed on a Hitachi U–4100 UV–vis spectrometer.