Article
Chemistry, Multidisciplinary
Juan G. Sanchez, Francisco M. Espinosa, Ruben Miguez, Ricardo Garcia
Summary: The study utilized AFM to measure and analyze the nanomechanical properties of live cells, revealing limitations in traditional elastic and viscoelastic models to characterize the mechanical response of cells under micrometer-scale deformations.
Article
Anatomy & Morphology
Mert Muhammed Koc, Mustafa Oguzhan Caglayan
Summary: In this study, mechanical, tribologic, and morphological characterization of recycled polypropylene beads were conducted using force spectroscopy and lateral-force microscopy. The results showed a significant correlation between grain size and compression-elastic moduli of the beads. Friction-maps of the beads were obtained through lateral-force microscopy for 25 square micrometer scanning areas.
MICROSCOPY RESEARCH AND TECHNIQUE
(2022)
Article
Physics, Applied
D. F. S. Costa, J. L. B. de Araujo, C. L. N. Oliveira, J. S. de Sousa
Summary: This work presents an analytical model for describing atomic force microscopy force curves of standard linear solid and power-law viscoelastic materials, considering the effects of indenter geometry and finite thickness. It is found that conical/pyramidal cantilevers are less affected by finite thickness effects compared to other shapes, such as spherical and flat punch indenters. Finite element modeling of the stress field distribution within the sample confirms this. The study also analyzes systematic errors when analyzing finite thickness samples with an infinite thickness force model, showing that for spherical indenters and indentation depths up to 20% of sample thickness, the mechanical response of viscoelastic materials will inaccurately resemble purely elastic behavior, even within timescales where viscoelastic relaxation should occur.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Biology
Laura Martinez-Vidal, M. Chighizola, M. Berardi, E. Alchera, I. Locatelli, F. Pederzoli, C. Venegoni, R. Luciano, P. Milani, K. Bielawski, A. Salonia, A. Podesta, M. Alfano
Summary: The micro-scale mechanical fingerprints of healthy bladder wall layers and their modifications in the presence of actinic cystitis or bladder tumors were investigated using atomic force microscopy and a nanoindenter. It was found that the healthy bladder wall is mechanically heterogeneous, with increasing stiffness from the urothelium to the lamina propria and a gradual decrease in stiffness towards the muscle outer layer. Fibrotic tissues showed stiffening due to increased extracellular matrix deposition in the lamina propria. An increase in tissue compliance was observed before tumor onset and invasion. This study provides valuable insights into the mechanical properties of the bladder and their alterations in disease states.
COMMUNICATIONS BIOLOGY
(2023)
Article
Multidisciplinary Sciences
Dilara Borte Emiroglu, Aleksandar Bekcic, Dalia Dranseikiene, Xinyu Zhang, Tomaso Zambelli, Andrew J. deMello, Mark W. Tibbitt
Summary: This study investigates the relationship between the macroscopic properties of granular hydrogels and the features of their microgel building blocks using contact mechanics. By studying the mechanics of the microgel packings and modeling the system as a collection of two-body interactions, the researchers were able to accurately describe the rheological properties of the granular hydrogels. These findings provide a rational design framework for improving the engineering of this fascinating class of materials.
Article
Biochemical Research Methods
Kai L. Metzner, Qi Fang, Rowan W. Sanderson, Alireza Mowla, Brendan F. Kennedy
Summary: This study systematically analyzes the impact of friction in quantitative micro-elastography (QME) and demonstrates that it is influenced by various experimental factors. Significant errors in elasticity estimation were observed in the absence of appropriate lubrication. The study also shows that friction can significantly reduce mechanical contrast in QME.
BIOMEDICAL OPTICS EXPRESS
(2023)
Article
Chemistry, Physical
Ivan Argatov, Xiaoqing Jin, Gennady Mishuris
Summary: In AFM-based studies of living cells, it is common practice to differentiate cells based on their elastic modulus, which is considered an effective characteristic of their mechanical properties. The elastic response of a cell to AFM indentation is influenced by the distance between the AFM probe and the solid support on which the cell is cultured. In addition to this bottom effect, AFM measurements can provide valuable information about the molecular brushes that cover living cells. This study develops a mathematical model that takes into account the bottom effect to determine the intrinsic effective elastic modulus of a single brush-coated cell. The model is illustrated using AFM data from testing a eukaryotic cell found in the literature.
Article
Physics, Applied
Zaicheng Zhang, Muhammad Arshad, Vincent Bertin, Samir Almohamad, Elie Raphael, Thomas Salez, Abdelhamid Maali
Summary: This study reports a contactless method to measure the viscoelastic rheological properties of soft gels, and demonstrates the elastohydrodynamic coupling between flow induced by probe oscillation and viscoelastic deformation of the gels.
PHYSICAL REVIEW APPLIED
(2022)
Article
Biophysics
Wenwei Xu, Saif Kabariti, Katherine M. Young, Steven P. Swingle, Alan Y. Liu, Todd Sulchek
Summary: By using an indentation-dependent pointwise Hertzian method, we measured the biomechanical spatial heterogeneity of ovarian and breast cancer cells. Recording stiffness at a particular strain may improve the comparison of cell material properties and produce higher contrast representations of cell mechanical properties. We observed that the perinuclear region of cancer cells was softer relative to the lamelopodial stiffness, and a significant stiffening phenomenon was found in the thin lamellipodial region.
JOURNAL OF BIOMECHANICS
(2023)
Article
Chemistry, Multidisciplinary
Yi Xu, Youquan Jia, Carlo Antonini, Yakang Jin, Longquan Chen
Summary: By immersing substrate-supported polymeric nanofilms in water, interfacial nanoblisters are formed as natural platforms for evaluating their mechanical properties. High-resolution force spectroscopy studies reveal that indentation tests must be conducted on the freestanding region around the nanoblister apex under an appropriate loading force to obtain load-independent, linear elastic deformations. The stiffness of the nanoblister increases with decreasing size or increasing covering film thickness, and this size effect can be explained by an energy-based theoretical model. This proposed methodology can provide an exceptional determination of the elastic modulus of the film and has potential applications in relevant fields.
Article
Materials Science, Multidisciplinary
J. Hargreaves, S. Moore, G. Yuan, D. Liu, H. Tipping, R. Abbott, J. Tufnail, H. Dawson, T. L. Martin
Summary: In this study, the microstructure of novel laser-keyhole Eurofer 97 welds was modeled using finite element thermal analysis and precipitate kinetics modeling. Microanalysis techniques such as scanning electron microscopy and high-speed atomic force microscopy were performed on representative specimens, revealing the presence of large void defects in the weld fusion zone.
MATERIALS & DESIGN
(2023)
Article
Engineering, Biomedical
Adam Wahlsten, Alberto Stracuzzi, Ines Luchtefeld, Gaetana Restivo, Nicole Lindenblatt, Costanza Giampietro, Alexander E. Ehret, Edoardo Mazza
Summary: The mechanical properties of the skin have been studied at both tissue and cellular length scales. The tension-compression nonlinearity of the collagen fiber network and the properties of the ground matrix contribute to the elasticity of the skin. Microscale indentation measurements do not engage the fiber network, and therefore cannot accurately predict the behavior of dermal fibroblasts.
ACTA BIOMATERIALIA
(2023)
Review
Construction & Building Technology
Chengwei Xing, Wei Jiang, Mingchen Li, Ming Wang, Jingjing Xiao, Zhoucong Xu
Summary: This article reviews the current application of AFM in the field of bitumen materials, including its working principle, sample preparation methods, probe selection methods, test parameters, phase characteristics of bitumen surfaces and interiors, as well as the application and technical challenges of AFM. Potential solutions are also recommended.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Biochemistry & Molecular Biology
Megan E. Dempsey, Graylen R. Chickering, Rafael D. Gonzalez-Cruz, Vera C. Fonseca, Eric M. Darling
Summary: This study demonstrates a workflow for surface protein discovery associated with cellular mechanophenotype. The method allows for the sorting and enrichment of live cells based on their mechanophenotype using surface protein biomarkers, followed by further characterization and differentiation studies.
CELLULAR AND MOLECULAR LIFE SCIENCES
(2022)
Article
Materials Science, Multidisciplinary
Wei Chen, Shanpeng Li, Zhiguang Guo
Summary: By studying the water-collection characteristics of natural spider silk, a nylon mesh with graded structures was fabricated using a simple spraying method and etching process. The unique wettability on the interface allows water drops to achieve mutual converging and fast downward transport. Additionally, fog flow simulation was conducted to analyze the velocity and pressure states in water collection, promoting the development of nylon mesh in water collection applications.
Article
Construction & Building Technology
Qi Zheng, Chengyao Liang, Jinyang Jiang, Haiyan Mao, Karen C. Bustillo, Chengyu Song, Jeffrey A. Reimer, Paulo J. M. Monteiro, Haimei Zheng, Shaofan Li
Summary: This study used scanning transmission electron microscopy to examine defects in cement particles at the single-atom level. The researchers identified different types of defects and found that they play a crucial role in cement hydration, facilitating dissolution and providing nucleation sites for hydration products.
CEMENT AND CONCRETE RESEARCH
(2024)
Article
Construction & Building Technology
Anuj Parashar, Shashank Bishnoi
Summary: This study investigated the hydration of siliceous fly ash, slag, and metakaolin with calcium hydroxide, and found that the rate of hydration and phase assemblage is influenced by the alkali and sulphate content, while siliceous fly ash is less affected by alkalis and sulphates.
CEMENT AND CONCRETE RESEARCH
(2024)
Article
Construction & Building Technology
Peimin Zhan, Juan Wang, Hanbing Zhao, Wengui Li, Surendra P. Shah, Jing Xu
Summary: This study investigates the influence of hydrothermal synthetic conditions on the properties of C-S-H seeds and reveals the correlations between C-S-H seeds properties, hydration kinetics, and paste performances. It is found that low reactant concentrations and calcium-to-silicon ratios facilitate the production of C-S-H seeds with small size and high purity. Using C-S-H seeds with high effective surface area accelerates the hydration process of cement, resulting in refined pore structure and enhanced strength.
CEMENT AND CONCRETE RESEARCH
(2024)
Article
Construction & Building Technology
Zhaozheng Meng, Qing-feng Liu, Neven Ukrainczyk, Song Mu, Yufei Zhang, Geert De Schutter
Summary: This study developed a numerical framework to investigate the combined attack of sulfate and chloride ions on cementitious materials in marine and saline environments. The study quantified various chemical reactions and solved the electrostatic potential caused by multi-ion coupling. The results showed that neglecting the multi-ions coupling effect could result in an underestimated chemical coupling strength in competitive chloride-sulfate binding.
CEMENT AND CONCRETE RESEARCH
(2024)
Article
Construction & Building Technology
Ning Li, Cise Unluer
Summary: This study aimed to improve the carbonation efficiency and reduce processing time of recycled concrete aggregates (RCAs). Wet carbonation with seawater was found to be more efficient than dry carbonation, leading to significant reduction in water absorption and increase in density of RCAs. The compressive strength of recycled aggregate concrete (RAC) prepared with 1-hour seawater carbonated RCAs was also improved. The formation of ettringite and calcite under wet carbonation contributed to the increased density and strength, as well as improved bond strength in the interfacial transition zone of RAC. Seawater presents several advantages as a medium for wet carbonation, including its abundant availability, CO2 capture capacity, and accelerated hydration and carbonation.
CEMENT AND CONCRETE RESEARCH
(2024)
Article
Construction & Building Technology
Yong Tao, Yining Gao, Yanjie Sun, Roland J. -M. Pellenq, Chi Sun Poon
Summary: Decalcification of calcium silicate hydrates (C-S-H) is an important issue for the long-term safety of cement-based infrastructures. Using molecular simulations, this study reveals an important mechanism of accelerated C-S-H decalcification in seawater, which involves ion exchange between surface Ca and electrical double layers, resulting in a decrease in Ca dissolution free energy. This finding enhances the understanding and prediction of cementitious materials' degradation.
CEMENT AND CONCRETE RESEARCH
(2024)
Article
Construction & Building Technology
Kumaran Coopamootoo, Enrico Masoero
Summary: This study uses kinetic simulations to investigate the relationship between dissolution rate and saturation index in minerals in solution. Two distinct regimes are observed, with stresses at crystallographic defects controlling the transition between them. A parameterization of the interaction potentials is proposed to obtain consistent interfacial energies with water. The findings contribute to the current discussion on controlling reactivity using materials and defects.
CEMENT AND CONCRETE RESEARCH
(2024)
Article
Construction & Building Technology
Faping Li, Qianshi Chen, Yiyan Lu, Yunlong Zou, Shan Li
Summary: In this study, the impact of functionalized multi-walled carbon nanotubes and a silane coupling agent on the performance and microstructure of alkali-activated fly ash/slag pastes was investigated. The results showed that the addition of these materials can prolong setting time, improve flowability and mechanical strength, and reduce mass loss and drying shrinkage.
CEMENT AND CONCRETE RESEARCH
(2024)
Article
Construction & Building Technology
Yaozeng Wang, Wencui Yang, Ai Zhang, Penghuan Liu, Yong Ge
Summary: Low-temperature low-field nuclear magnetic resonance was used to analyze icing in water saturated white cement paste specimens during the freeze-thaw process at different temperatures. The experimental results were compared with classical theory, showing agreement at certain temperatures but discrepancies at others. New equations were proposed based on the analysis of specimens saturated with different solutions to relate the volume of frozen water to temperature during freezing and thawing of cementitious materials.
CEMENT AND CONCRETE RESEARCH
(2024)
Article
Construction & Building Technology
Shengjie Yan, Yingjie Liang
Summary: This paper proposes a fractal derivative model with a non-linear distributed-order (DOFM) to describe the multi-scaling behaviors of particle diffusion in alkali-activated materials. The DOFM is tested using experimental data and is found to effectively describe the multi-scaling diffusion behaviors of particles in the materials.
CEMENT AND CONCRETE RESEARCH
(2024)
Article
Construction & Building Technology
Cecilia Pesce, Richard J. Ball, Marco Molinari, Shaun Reeksting, Giovanni Luca Pesce
Summary: This study evaluates the effect of ten organic additives on the microstructure of portlandite crystals during CaO hydration. It was found that the presence of carbohydrates and sulfonates can alter the structure of portlandite and the properties of lime can be controlled by adding carbohydrates. This has significant implications for the development of new binders and reducing CO2 emissions.
CEMENT AND CONCRETE RESEARCH
(2024)
Article
Construction & Building Technology
Daniel Jansen, Alexander German, Dominique Ectors, Frank Winnefeld
Summary: This study used X-ray diffraction and Rietveld refinement technique to investigate a hydrous carbonate-containing brucite and found that the 001 reflection of this phase split into different patterns at different temperatures. The presence of water and/or carbonate influenced the distance between the layers in the brucite structure.
CEMENT AND CONCRETE RESEARCH
(2024)
Article
Construction & Building Technology
Dylan Singh, Trinh Thao My Nguyen, Evann Bustamantes, Abdul Wahab, Ahmad Hamzah Yousaf, Ian Shortt, Frank W. Foss Jr, Maria Konsta-Gdoutos, Sang Soo Lee, Erika La Plante
Summary: This study analyzes the chemical structure and morphology of magnesium silicate hydrate (MSH) grown under different concentration ratios and temperatures. The results show that increasing the magnesium to silicon ratio reduces silicate polymerization in MSH, and at higher temperatures and longer reaction times, oriented attachment of nanoparticles and enhanced crystallinity are observed. These findings provide insights into the precise chemical synthesis of MSH and its widespread use as a binder in construction.
CEMENT AND CONCRETE RESEARCH
(2024)
Article
Construction & Building Technology
J. C. O. Zepper, S. R. van der Laan, K. Schollbach, H. J. H. Brouwers
Summary: This study presents a method to calculate the main phases of BOF slag based on chemical composition and validates the proposed final model through quantitative model assessment and validation approaches.
CEMENT AND CONCRETE RESEARCH
(2024)
Article
Construction & Building Technology
Yierfan Maierdan, Samuel J. Armistead, Rebecca A. Mikofsky, Qiqi Huang, Lola Ben-Alon, Wil V. Srubar III, Shiho Kawashima
Summary: This research investigated the effects of sodium alginate on the stability and 3D printability of kaolinite suspensions. The findings showed that sodium alginate could enhance the stability of kaolinite and improve the strength of printable mixtures, as well as shift the printability window.
CEMENT AND CONCRETE RESEARCH
(2024)
