Zetasizer nano equipment

The morphology, composition, and particle size of the nBGs were analyzed using scanning electron microscopy (SEM) equipped with X-ray dispersive energy elemental microanalysis (EDX) in a JEOL-model microscope (JSM-IT300LV, Tokyo, Japan). In addition, particle size distribution was analyzed by dynamic light scattering (DLS) using Zeta Sizer Nano equipment (Malvern Instruments, Malvern, UK) at 25 °C with a scattering angle of 90° and a pH 7.4 nBG suspension of 1 mg/mL prepared in MilliQ water. nBGs were also analyzed for total attenuated reflectance by means of Fourier transform infrared spectroscopy (ATR-FTIR) using an Agilent Cary 630 ATR-FTIR spectrometer (Santa Clara, CA, USA), X-ray diffraction (XRD) using an X-ray diffractometer (STOE StadiP, Darmstadt, Germany), and atomic force microscopy (AFM) using a Nanosurf AG microscope (Gräubernstrasse Switzerland).

Firstly, we made a dispersion of MWCNTs in water MilliQ (ultrapure water of laboratory) and Triton TX-100 surfactant through an ultrasonic tip and after that, we study the stabilization over time, taking spectra in a UV-Vis spectrophotometer (Shimadzu, Bucaramanga, Colombia) and Zetasizer Nano equipment (Malvern, Bucaramanga, Colombia), for 1, 2, 4, 10 and 13 weeks. The experiment was finished the thirteen weeks, because the MWCNTs were falling out abruptly in the solution. To evaluate the structural damage induced in the first week, Raman microscopy was used. Later, it was prepared two series of cement paste cylinders, at first and fourth weeks after the sonication process, observing that the mechanical properties are maintained. It was considered the fourth week since, for later weeks, the dispersion fall-out abruptly and the nanotubes were agglomerated. Finally, the elastic modulus of the cylinders was obtained through HM 5030 Master Loader equipment (Humboldt, Manizales, Colombia). Experimental parameters of the dispersion were based on some previous work carried out by us.