σigma

The living specimens were decapitated under a continuous variable times stereomicroscope (Stemi 508, Zeiss, Germany), and the heads were fixed in 2.5% glutaraldehyde for 6 h at 4 °C. After rinsing them thrice for 10 min each time with 0.1 M PBS buffer, they were dehydrated in an ascending series of ethanol (30%, 50%, 70%, 80%, 85%, 90%, and 95%) for 20 min at each concentration. Then, they were completely dehydrated twice in 100% ethanol for 20 min each time. Subsequently, the samples were rinsed twice in 100% acetone. After air drying, the samples were critical-point dried (K850, Quorum, England) and mounted with the dorsal-side, lateral-side, and ventral-side on the surface of aluminous stubs with double-sided sticky tape. The sputter coating with gold/palladium was performed with a sputter coater (SC7620, Quorum, England) and subsequently examined with a scanning electron microscope (ΣIGMA, Carl Zeiss, Germany) at an accelerating voltage of 2–6 kV.

Scanning electron microscope (SEM) pictures were acquired using a ΣIGMA (Carl Zeiss Microscopy GmbH, München, Germany) scanning electron microscope with an acceleration potential of 5 kV. Acrylic paint film mock-ups were gold-metalized using an Agar Scientific auto sputter coater.

Scanning electron microscopy (ΣIGMA, ZEISS, Oberkochen, Germany) was used to observe the longitudinal morphology and cross-sectional morphology of ZnO/TM/PET fiber samples to analyze the dispersion of the ZnO/TM composite powder in the fibers. The samples were processed by gold sputtering with an accelerating voltage of 20 kV.

The surface morphology and chemical composition of the samples were examined on ascanning electron microscope (SEM, Zeiss ΣIGMA, Oberkochen, Germany) with an energy-dispersive X-ray spectroscopy (EDS, OxfordINCA Energy, Oxford, UK) attachment by a secondary electron detector using an accelerating voltage of 20 kV. The constituent-phase structure of the samples was determined by X-ray diffraction (XRD, Shimadzu XRD-6100, Kyoto, Japan) with Cu K_α in a scanning range between 10° and 80°. An X-ray photoelectron spectroscopy (XPS, ESCALAB250, Thermo VG, Waltham, NV, USA) with an Al K_α (λ = 1486.6 eV) was used to determine the chemical states of thesamples after sputtering for 60 s to remove the surface contaminants. The binding energies were referenced to the C 1s line at 284.6 eV.

Fungal biomass was filtrated from culture medium, washed for 2 or 3 times using 200 mL of ultrapure water. Afterwards, the fungal mycelium was resuspended in 50 mL of ultrapure water, and centrifuged at 10,000 rpm for 15 min at 4 ℃. The suspension was recognized as the solution of BEPS. The culture medium at different culture period was collected, dialyzed (molecular weight cutoff: 3500 Da) against deionized water for 5 days. The obtained solution was designated as SEPS.
Dry weight of fungal mycelia was measured after the biomass was dried in a vacuum freezing dryer for 24 h to a constant weight. Field emission scanning electron microscopy (SEM, Zeiss Σigma, Germany) and energy dispersive X-ray spectrometer (EDS, Oxford Inca, UK) were used to observe the morphology and element composition of the fungal mycelium before and after BEPS extraction.

X-ray fluorescence (XRF, S8 Tiger, Bruker AXS Corporation, China) was used to analyze the major element compositions in the CA samples. The trace elements in the leachate were measured using inductively coupled plasma mass spectroscopy (ICP-MS, Thermo ICAP RQ, Bremen, German). Before elemental analysis, the solid samples were digested in a microwave instrument using the method described in our previous study [25 (link)]. A scanning electron microscope (FE-SEM, ZEISS ΣIGMA, Oberkochen, German), in conjunction with an energy-dispersive X-ray spectrometer (Oxford X-MaxN 20, Shanghai, China) (collectively, SEM-EDS), was applied to observe the particles of iron and REY. The images were captured through a retractable solid-state backscatter electron detector, which was more easily to find REY/iron-containing minerals in view of the bottom position of the periodic table of elements. The specific surface area of CA samples was measured by an Autosorb-iQ analyzer (Quantachrome, Boynton Beach, FA, USA) followed by the BET method. The pycnometer method was used for the density determination of the samples by reference to distilled water. The particle size distribution of three samples was obtained using a laser diffraction analyzer (Microtract S3500, York, PA, USA).

The surface chemical analysis was performed by using a Thermo VG Theta Probe XPS spectrometer with a μ-spot monochromatic Al Kα source. A fixed analyzer transmission mode with a pass energy of 150 eV was used to acquire XPS survey spectra; a pass energy of 100 eV was used for the acquisition of XPS high-resolution spectra.
The morphological analysis was performed by TEM (FEI, TECNAI T12, operated at 120 kV) and SEM (Field Emission, Zeiss ΣIGMA, operated at 5–10 kV, 10 μm aperture).