Actividades en Universidades Saludables
F. ACTIVIDADES DEL PROGRAMA PRESUPUESTAL DE PREVENCIÓN DEL CANCER
II. ACTIVIDADES DE PARTICIPACIÓN COMUNITARIA A. PROGRAMA ARTICULADO NUTRICIONAL (U0012)
1.1. Nuclear magnetic resonance (NMR)
NMR spectroscopy experiments were performed using a Bruker Avance III HD spectrometer at 400.15 MHz for 1H and 376.52 MHz for 19F spectroscopies. The spectra were treated with a TopSpin 3.2 software and the chemical shift (
𝛿
) was presented by the unit of parts per million (ppm). The deuterated solvents used in this study were DMSO-d6 (𝛿
𝐻=
2.50 ppm), acetone-d6 (𝛿
𝐻=
2.04 ppm) and acetonitrile-d3 (𝛿
𝐻=
1.94 ppm). Multiplicities of the peaks were reported as: s = singlet, d = doublet, t = triplet, m = multiplet. Sample preparation for NMR analysis.
The chemicals dissolved in approximate 0.3 mL of deuterated solvent was added in a 5 mm of diameter tube for NMR. In some cases, an insert-tube (d = 4 mm) containing the reference solution was used to calibrate the quantities of product in the NMR tube. For each measure, 0.2 mL of sample was filled in the NMR tube and the small tube of reference was inserted. The reference is a solution of tetraethylammonium tetrafluoroborate (Et4N+BF4) 0.5 M dissolved in DMSO-d6.
Pulsed-gradient spin-echo (PSGE-NMR)
The self-diffusion coefficients were measured by PGSE-NMR using a Bruker Avance III HD spectrometer equipped with a diffusion probe of 5 mm and a temperature regulation unit (20 - 80°C). The frequencies are 400.13, 376.50, and 155.51 MHz for 1H, 19F and 7Li, respectively. For the 133Cs PFG-NMR, experiments were performed using a Bruker 300 spectrometer at the frequency of 39.351 MHz. Stimulated echo sequence was used. The maximum magnitude of the pulsed field gradient was 900 G.cm-1, the diffusion delay Δ was adjusted between 50 and 100 ms, and the gradient pulse length δ was set between 1ms and 5ms depending on the diffusion coefficient and the nature of the mobile species. For the liquid samples, some measurements were also performed with Δ = 200 ms as well to confirm that no convection artifacts occur. The self-diffusion coefficients were determined from the classical Stejskal-Tanner equation:1
ln(I/I0) = -DG2γ2δ2(Δ-δ/3)
where G is the magnitude of the two gradient pulses applied, γ is the gyromagnetic ratio of the nucleus under study and I and I0 are the integrated intensities of the signal obtained respectively with and without gradient pulses. Here, we used 16 equally spaced gradient steps for each PGSE-experiment. Data acquisition and treatment were performed with Bruker Topspin software.
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Sample preparation
The ILs and polymers were filled into small diameter tube (d = 4 mm) in the glove box, then were sealed to prevent the humidity. The level of sample was ensured at about 1.5 cm along the tube. The tubes were covered with the plastic caps and closed by flame welding. The measurements were carried out from 20 °C to 80 °C.
1.2. Size exclusion chromatography coupled multi-angle laser light scattering (SEC-MALLS) The SEC measurements were performed with the WATERS 515 HPLC, with a differential refractometer SOPARES RI2000 and a light scattering detector WYATTDAWN EOS at 690 nm. The data were treated with ASTRA 6 software. NaNO3 (0.1 M) in DMF (Alfa aesar-HPLC grade 99.7%) was used as solvent at a flow rate of 1 mL.min-1 through a 10 AGILENT 2xPLgel-Mixed-D column. The molecular weight was determined by the signals of the light scattering detector and the refractometer assuming that all of the injected product passing through the column was analyzed by the MALLS detector and was also compared with the polystyrene equivalent.
Sample preparation
An amount of polymer (~20 mg) dissolved in the appropriate solvent (~2 mL) for SEC analysis. Solution of 1 wt % of polymer in solvent was filtered with the PP Millipore filter of 0.45 µm before injecting into the machine.
1.3. Atomic absorption spectroscopy (AAS)
The ion exchange efficiency was determined using a Perkin Elmer PinAAcle 900F AAS, and the data were treated with the Syngistix software. The lamps for absorption corresponding to different elements such as Li, Na, K, and Mg were used to detect the presence of these ions in the sample. Unfortunately, we couldn’t measure the concentration of Cs due to the lack of Cs lamp. However, all of the ionomers after reaction containing a mixture of Na+ and K+ as cations were then transformed to Cs+ through the ion-exchange process. The fact that the ionomer Cs-form contain tiny (or no measurable) quantities of Na+ and K+ can further affirm a successful ion-exchange process. The solution containing a definite concentration, usually about 5 ppm of the interested ion, was injected into the machine. Each sample were tested 3 times with different lamps such as Na, K, and an element of interest, to ensure the reasonable results. The efficiency of ion exchange process was presented by the percentages of concentration of each element contained in 5 ppm of polymer.
Sample preparation
The ionomers were dissolved in distilled water and the Mn+ concentration estimated from the mass molar of ionomer was approximately 5 ppm. For the copolymers, an amount of polymer was
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degraded in acid nitric extra pure and filtered with a PTFE syringe-filter of 0.45 µm. Distilled water was used to dilute the acid from ~ 65 % to ~ 2 % before inject in the machine.
1.4. Infrared spectroscopy (IR)
FTIR analyses were carried out using an IR spectrometer Spectrum ONE (Perkin Elmer). The samples were analyzed in absorbance in wavenumber range between 4000 and 400 cm-1. The IR spectra were acquired with 16 accumulations and a resolution of 1 cm-1. The ionomers (non- crosslinked and crosslinked) and ionic liquid were placed in a liquid cell with ZnSe window. All of the IR measurements were performed in N2 atmosphere. Before the treatment, the IR spectra were normalized respectively at 1450 and 654 cm-1 for ionomers and ionic liquids.
1.5. Field-Emission Scanning Electron Microscopy (SEM)
SEM analyses were performed with an Ultra 55 (Zeiss) microscope using a voltage of 3 kV, and a SE detector, the obtained image was post-treated and analyzed using ImageJ. In details, the NCC dispersion was analyzed with a binaryzation and a statistic analysis of particles. Then the diameter distribution of particles can be extracted and presented using Histogram from OrginPro.
Sample preparation
The dispersion of nano crystalline celluloses into the cross-linked ionomer was observed on the fracture surface of membranes. To obtain a net fracture surface, samples were frozen in liquid nitrogen, then fractured and coated with carbon (thickness of coating layer was about 5 – 10 nm). The LFP electrodes were fixed to the SEM support with graphite tape and coated with a layer of carbon.