DOI: 10.5281/zenodo.10053980
title: Composite of graphene and silver nanoparticles obtained by low-dose gamma irradiation

description: Content:

TEM.zip - TEM images of composites, file type .tif and .dm3

VINCA_FTIR.zip - FTIR data of graphene oxide and exfoliated graphene, file type .csv

VINCA_UV-Vis.zip - FTIR data of graphene oxide and exfoliated graphene composites, file type .csv

IEMN_VNA_Graphene-AgNP - EMI shielding measurement of graphene oxide and exfoliated graphene composites, file type .xlsx

VINCA_CA_graphene-AgNP.jpg - contact angle measurement of graphene oxide and exfoliated graphene composites

VINCA_532nmLASER.zip - temperature elevation measurements of graphene oxide and exfoliated graphene composites, file type .csv

FTPO_TGA_Graphene-AgNP.zip - TGA data of graphene oxide and exfoliated graphene composites, file type .txt

 

 
description: Transmission electron microscope (TEM) examination of the samples was carried out using a JEOL (Tokyo, Japan) JEM-2100F using an acceleration voltage of 200 kV. The samples were dispersed in ethanol using an ultrasound bath and a drop of the mixture was placed on lacey carbon copper grids (200 mesh) and dried in the air.
description: Fourier transform infrared spectroscopy (FTIR) was recorded on Avatar 370 Thermo Nicolet spectrometer in the form of a KBr pellet.
description: The LLG-uniSPEC 2 spectrophotometer was used to record the UV-Vis absorption spectra. To do the measurements, a small quantity of the dried material was dispersed in water, and spectra were recorded in quartz cuvettes at room temperature.
description: Thermogravimetric analysis (TGA) tests were performed on a TGA/DSC 3+ (Mettler Toledo instruments, Greifeensee, Schweiz) under nitrogen (20 ml/min) at a heating rate of 5 °C/min, from 25 to 700 °C. After achieving this temperature the samples were subjected to oxygen flow (20 ml/min) for an additional 20 minutes at the constant temperature of 700 °C.
description: EMI shielding efficiency measurements were conducted using a Vector Network Analyzer (VNA) from Keysight Technologies (Streamline P5008A) operating at 150 kHz-53 GHz. The VNA was connected through high stable coaxial cables to a dedicated coaxial set-up to measure the complex reflection (S11) and transmission (S21) up to 18 GHz. The EMIs of the different samples are related to the residual RF signals transmitted through the shield. In other words, the amplitude of the transmission coefficient corresponds to RF signals that are neither reflected nor absorbed by the samples. Preliminary to the microwave characterization of the samples, a vector calibration was performed at the output of the coaxial cables to remove systematic errors. Input RF power was set to -15 dBm, and intermediate frequency (IF) bandwidth was set to 100 Hz resulting in a time per frequency of 10 ms. All measurements were conducted at room temperature. Each sample was sandwiched between two thin films of cellulose (named ''paper'' in the following) to avoid contamination of the coaxial flange.
description: Contact angle measurements were carried out by using the sessile drop method on the Theta Lite contact angle meter (Biolin Scientific). For the data acquisition, ∼6 μl of deionized water (MilliQ 18.2 mΩ/cm) was carefully dropped on the samples using a micro syringe. All measurements were performed at ambient conditions (25 °C) and immediately after droplet stability. The data were analyzed using OneAttension software (version 4.0.3).
description: Photothermal conversion efficiency measurements were performed in 1 × 1 × 4.5 cm spectrometer quartz cuvettes at room temperature (22.3 °C). Stable homogeneous dispersions of the samples in water with a concentration of 1 mg/ml were exposed to 532 nm continuous wave (CW) laser radiation. The laser power was 180 mW, the laser power density was 1.38 W/cm2, and the beam was circular with 1.5 mm in diameter. To ensure the perpendicular incident laser beam to the cuvette wall, a special cuvette holder was used. The center of the laser spot was placed at a fixed position in the center of the cuvette. The temperature evolution was recorded by a thermocouple (accuracy 0.1 °C) every 30 s. The samples were irradiated for 10 minutes (heating cycle) until they reached thermal equilibrium. Then the laser was switched off to allow the sample to cool down to room temperature and the temperature was monitored for the following 15 minutes (cooling cycle).