TY - JOUR
T1 - Characterization of adhesion strength between carbon nanotubes and cementitious materials
AU - Marrero Rosa, Raúl E.
AU - Corr, David J
AU - Espinosa, Horacio D.
AU - Shah, Surendra P
N1 - Funding Information:
Previous research shows a 30% increase in the bulk Young's modulus of nanomodified concrete, which is correlated to a 50% increase in the contact modulus of the interfacial transition zone (ITZ) using Atomic Force Microscopy - PeakForce Quantitative Nanomechanical Mapping (AFM-QNM) [1,2]. In addition, a chemical composition analysis with Scanning Electron Microscope - Energy Dispersive X-ray Spectroscopy (SEM-EDS) indicates that CNF addition creates an uniform microstructure in the ITZ region compared to control samples [2]. The results show tighter distribution of calcium-to-silica (Ca/Si) under 2.5 which corresponds to Calcium-Silicate-Hydrate (C–S–H) region [2]. This supports the hypothesis that MWCNT and CNF serve as nucleation site for C–S–H growth [11] which increases the C–S–H content and the structural homogeneity within the ITZ. These changes in matrix properties due to the nanofibers are not observed with macro- and micro-scale fibers addition which leads to studying the fundamentals of the interaction between the nanofibers and the components of the cement matrix.This material is based upon work supported by the National Science Foundation, Alexandria, VA, USA Graduate Research Fellowship under Grant No. (DGE-1842165) of Raúl E. Marrero Rosa, Ph.D. Authors give a special thanks to Rafael A. Soler Crespo, Ph.D. for collaborating in training and conceptualization at the early stage of the project. Authors thanks the following people for collaborations: Kavya Mendu, Ph.D. and Yuan Gao, Ph.D. (Dr. David Corr and Dr. Surendra Shah research group), Patricio Carnelli, Ph.D. and Yechan Won from (Dr. Kimberly Gray, Environmental Laboratory research group), and Siyan Dong, Ph.D. (Dr. Horacio Espinosa, Mechanical Engineering Laboratory). Thanks to Materials Characterization and Imaging Facility (MatCI), NUANCE – EPIC (SEM Hitachi S – 3400, S – 4800, and S – 8030), and NUANCE – SPID (Bruker Icon AFM) from Northwestern University Core Facilities.
Funding Information:
This material is based upon work supported by the National Science Foundation, Alexandria, VA, USA Graduate Research Fellowship under Grant No. ( DGE-1842165 ) of Raúl E. Marrero Rosa, Ph.D. Authors give a special thanks to Rafael A. Soler Crespo, Ph.D. for collaborating in training and conceptualization at the early stage of the project. Authors thanks the following people for collaborations: Kavya Mendu, Ph.D. and Yuan Gao, Ph.D. (Dr. David Corr and Dr. Surendra Shah research group), Patricio Carnelli, Ph.D. and Yechan Won from (Dr. Kimberly Gray, Environmental Laboratory research group), and Siyan Dong, Ph.D. (Dr. Horacio Espinosa, Mechanical Engineering Laboratory). Thanks to Materials Characterization and Imaging Facility (MatCI), NUANCE – EPIC (SEM Hitachi S – 3400, S – 4800, and S – 8030), and NUANCE – SPID (Bruker Icon AFM) from Northwestern University Core Facilities.
Publisher Copyright:
© 2023 Elsevier Ltd
PY - 2023/4
Y1 - 2023/4
N2 - Multi-walled carbon nanotube (MWCNT) and carbon nanofiber (CNF) additions increase the elastic modulus, flexural strength, and toughness of Portland cement concrete. However, the interaction mechanism between cement constituents and these nanomaterials is not fully understood. A modified MWCNT-coated atomic force microscopy (AFM) probe is developed by coating a silica particle with oxidized MWCNT through layer-by-layer assembly and adhering it to a tipless AFM cantilever. The probe allows measurement of adhesion between MWCNT and the substrate with a force control procedure. SEM-EDS is acquired in the same region as AFM measurements through a benchmarking scheme to correlate chemistry with the measured adhesion. Statistical deconvolution shows C–S–H regions have lower adhesion to MWCNT than intermixed regions (C–S–H/Clinker). Furthermore, in C–S–H regions, the normalized adhesion strength increases with calcium concentration. This result is due to the higher interaction between the oxygen functional groups in the MWCNT surface and the calcium in the substrate.
AB - Multi-walled carbon nanotube (MWCNT) and carbon nanofiber (CNF) additions increase the elastic modulus, flexural strength, and toughness of Portland cement concrete. However, the interaction mechanism between cement constituents and these nanomaterials is not fully understood. A modified MWCNT-coated atomic force microscopy (AFM) probe is developed by coating a silica particle with oxidized MWCNT through layer-by-layer assembly and adhering it to a tipless AFM cantilever. The probe allows measurement of adhesion between MWCNT and the substrate with a force control procedure. SEM-EDS is acquired in the same region as AFM measurements through a benchmarking scheme to correlate chemistry with the measured adhesion. Statistical deconvolution shows C–S–H regions have lower adhesion to MWCNT than intermixed regions (C–S–H/Clinker). Furthermore, in C–S–H regions, the normalized adhesion strength increases with calcium concentration. This result is due to the higher interaction between the oxygen functional groups in the MWCNT surface and the calcium in the substrate.
KW - Adhesion interaction
KW - Carbon nanotube
KW - Cementitious composite
KW - Chemical correlation
KW - Concrete reinforcement
UR - http://www.scopus.com/inward/record.url?scp=85148043584&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85148043584&partnerID=8YFLogxK
U2 - 10.1016/j.cemconcomp.2023.104953
DO - 10.1016/j.cemconcomp.2023.104953
M3 - Article
AN - SCOPUS:85148043584
SN - 0958-9465
VL - 138
JO - Cement and Concrete Composites
JF - Cement and Concrete Composites
M1 - 104953
ER -