jesusrod

• Sanchez, Jesus Rodriguez; Liberto, Teresa; Barentine, Catherine & Dysthe, Dag Kristian (2020). Mechanisms of phase transformation and creating mechanical strength in a sustainable calcium carbonate cement. Materials. 13(16). doi: 10.3390/MA13163582. Full text in Research Archive Show summary

  Calcium carbonate cements have been synthesized by mixing amorphous calcium carbonate and vaterite powders with water to form a cement paste and study how mechanical strength is created during the setting reaction. In-situ X-ray diffraction (XRD) was used to monitor the transformation of amorphous calcium carbonate (ACC) and vaterite phases into calcite and a rotational rheometer was used to monitor the strength evolution. There are two characteristic timescales of the strengthening of the cement paste. The short timescale of the order 1 h is controlled by smoothening of the vaterite grains, allowing closer and therefore adhesive contacts between the grains. The long timescale of the order 10–50 h is controlled by the phase transformation of vaterite into calcite. This transformation is, unlike in previous studies using stirred reactors, found to be mainly controlled by diffusion in the liquid phase. The evolution of shear strength with solid volume fraction is best explained by a fractal model of the paste structure.

• Sanchez, Jesus Rodriguez; Olivenza, Miguel Angel Pacha & Martin, Maria Luisa Gonzalez (2019). Bactericidal effect of magnesium ions over planktonic and sessile Staphylococcus epidermidis and Escherichia coli. Materials Chemistry and Physics. ISSN 0254-0584. 221, p. 342–348. doi: 10.1016/j.matchemphys.2018.09.050. Full text in Research Archive
• Renard, Francois; McBeck, Jessica Ann; Cordonnier, Benoit; Zheng, Xiaojiao; Kandula, Neelima & Sanchez, Jesus Rodriguez [Show all 12 contributors for this article] (2019). Dynamic In Situ Three-Dimensional Imaging and Digital Volume Correlation Analysis to Quantify Strain Localization and Fracture Coalescence in Sandstone. Pure and Applied Geophysics (PAGEOPH). ISSN 0033-4553. 176, p. 1083–1115. doi: 10.1007/s00024-018-2003-x. Full text in Research Archive Show summary

  Advances in triaxial compression deformation apparatus design, dynamic X-ray microtomography imaging, data analysis techniques, and digital volume correlation analysis provide unparalleled access to the in situ four-dimensional distribution of developing strain within rocks. To demonstrate the power of these new techniques and acquire detailed information about the micromechanics of damage evolution, deformation, and failure of porous rocks, we deformed 3-cm-scale cylindrical specimens of low-porosity Fontainebleau sandstone in an X-ray-transparent triaxial compression apparatus, and repeatedly recorded three-dimensional tomograms of the specimens as the differential stress was increased until macroscopic failure occurred. Experiments were performed at room temperature with confining pressure in the range of 10–20 MPa. Distinct grayscale subsets, indicative of density, enabled segmentation of the three-dimensional tomograms into intact rock matrix, pore space, and fractures. Digital volume correlation analysis of pairs of tomograms provided time series of three-dimensional incremental strain tensor fields throughout the experiments. After the yield stress was reached, the samples deformed first by dilatant opening and propagation of microfractures, and then by shear sliding via grain rotation and strain localization along faults. For two samples, damage and dilatancy occurred by grain boundary opening and then a sudden collapse of the granular rock framework at failure. For the third sample, a fault nucleated near the yield point and propagated in the sample through the development of transgranular microfractures. The results confirm findings of previous experimental studies on the same rock and provide new detailed quantifications of: (1) the proportion of shear versus dilatant strain in the sample, (2) the amount of dilatancy due to microfracture opening versus pore opening when a fault develops, and (3) the role of grain boundaries and pore walls in pinning microfracture propagation and slowing down the rate of damage accumulation as failure is approached. Our study demonstrates how the combination of high-resolution in situ dynamic X-ray microtomography imaging and digital volume image correlation analysis can be used to provide additional information to unravel brittle failure processes in rocks under stress conditions relevant to the upper crust.

• Sanchez, Jesus Rodriguez; Myszka, Barbara; Boccaccini, Aldo Roberto & Dysthe, Dag Kristian (2019). Setting behavior and bioactivity assessment of calcium carbonate cements. Journal of The American Ceramic Society. ISSN 0002-7820. 102(11), p. 6980–6990. doi: 10.1111/jace.16593. Full text in Research Archive Show summary

  Calcium carbonate cements have emerged in the last few years as an attractive candidate for biomedical applications. They can be easily prepared by mixing water with two metastable calcium carbonate phases––amorphous calcium carbonate (ACC) and vaterite––which (re)crystallize into calcite during setting reaction. The transformation kinetics (and therefore the final surface cement composition) strongly depends on the initial mixture design and is controlled by the dissolution of ACC, whereas calcite nucleation typically controls their recrystallization in fluid batch experiments. Novel compositions are presented in this paper by incorporating organic molecules as a proxy to test their capability to carry on other biomolecules like proteins or antibiotics. The hardened samples are microporous and show excellent bioactivity rates, although their mechanical properties still remain poor. However, this would not be a handicap for in‐vivo applications such as bone filling, especially in low mechanical stress locations.

• Li, Lei; Sanchez, Jesus Rodriguez; Kohler, Felix; Røyne, Anja & Dysthe, Dag Kristian (2018). Microfluidic control of nucleation and growth of CaCO3. Crystal Growth & Design. ISSN 1528-7483. 18(8), p. 4528–4535. doi: 10.1021/acs.cgd.8b00508. Full text in Research Archive Show summary

  A novel method for studying nucleation and growth of CaCO3 crystals in situ has been developed and tested rigorously. We demonstrate that precise flow control is essential and how this is achieved. The method has the advantage that one may study single crystals of polymorphs that are thermodynamically unstable in collections of many crystals and that one obtains precise and accurate growth rates without any extra assumptions. We also demonstrate that, at low supersaturations where 2D nucleation does not occur, we measure the growth rate constant of calcite to be 5 times larger than that reported by batch methods and 2 orders of magnitude larger than that measured by atomic force microscopy. Considering the large interest in calcite growth in, for example, geoscience, environmental science, and industry, it is important to explain the discrepancy of growth rate constants between different methods. The method presented here can easily be applied to many other minerals.

• Sanchez, Jesus Rodriguez; Zhang, Quing & Dysthe, Dag Kristian (2018). Microstructure and Relative Humidity Effects on Long-Term Indentation Creep Properties of Calcium Carbonate Cement. Preprints. ISSN 2310-287X. doi: 10.20944/preprints201810.0671.v1. Full text in Research Archive
• Sanchez, Jesus Rodriguez; Gallardo-Moreno, Amparo M.; Bruque, José M. & Gonzalez-Martin, Maria Luisa (2016). Adsorption of human fibrinogen and albumin onto hydrophobic and hydrophilic Ti6Al4V powder. Applied Surface Science. ISSN 0169-4332. 376, p. 269–275. doi: 10.1016/j.apsusc.2016.03.014. Full text in Research Archive
• Sanchez, Jesus Rodriguez; Sanchez-Gonzalez, Estibaliz; Guiberteau, Fernando & Ortiz, Angel (2015). Contact-mechanical properties at intermediate temperatures of ZrB2 ultra-high-temperature ceramics pressureless sintered with Mo,Ta, or Zr disilicides. Journal of the European Ceramic Society. ISSN 0955-2219. 35(11), p. 3179–3185. doi: 10.1016/j.jeurceramsoc.2015.04.023. Full text in Research Archive

View all works in NVA

• Sanchez, Jesus Rodriguez; Myszka, Barbara; Dysthe, Dag Kristian & Boccaccini, Aldo (2017). Biomineralization study of calcium carbonate cements. Full text in Research Archive
• Sanchez, Jesus Rodriguez (2017). Lab meeting: Experimental study of brittle or ductile behaviour of self-healing cement. Full text in Research Archive
• Sanchez, Jesus Rodriguez; Liberto, Teresa; Zhang, Qing; Barentine, Catherine & Dysthe, Dag Kristian (2017). Rheological and long-term indentation creep properties of calcium carbonate cements. Full text in Research Archive
• Sanchez, Jesus Rodriguez; Liberto, Teresa; Zhang, Qing; Barentine, Catherine & Dysthe, Dag Kristian (2017). Lab meeting: Rheological and long-term indentation creep properties of calcium carbonate cements. Full text in Research Archive
• Sanchez, Jesus Rodriguez; Cordonnier, Benoit; Renard, Francois & Dysthe, Dag Kristian (2016). Transition between brittle and ductile behaviour on carbonate rocks: an X-ray tomographic analysis. Full text in Research Archive
• Sanchez, Jesus Rodriguez & Dysthe, Dag Kristian (2016). Synthesis of calcium carbonate particles via continuous flow microfluidics. Full text in Research Archive
• Sanchez, Jesus Rodriguez & Dysthe, Dag Kristian (2016). A tour around research in the Depart. of Physics. First stop" NanoHeal: Nano-tailoring organo-mineral materials". Full text in Research Archive
• Sanchez, Jesus Rodriguez (2019). Experimental study of brittle or ductile behaviour of mineral cements. Universitetet i Oslo. Full text in Research Archive

View all works in NVA