Article
Materials Science, Multidisciplinary
Wenhui Cao, Qi Ding, Peng Ding, Litian Hu, Chaobin Liu, Wei Yu
Summary: The rheological properties of PNIPAM microgels and the formation mechanism of tribofilms at the sliding interface during friction were investigated. It was found that PNIPAM microgels could effectively improve the tribological performance above the critical solution temperature, by forming a gel layer that changes the friction interface and reduces the friction coefficient.
ACS APPLIED POLYMER MATERIALS
(2022)
Article
Engineering, Industrial
S. Volz, J. Launhardt, N. Bay, C. Hu, P. Moreau, L. Dubar, C. Nielsen, K. Hayakawa, K. Kitamura, P. Groche
Summary: The global target of the cold forging industry is to use lubricants without conversion layers. Compared to traditional lubricant systems based on zinc phosphate coatings, these lubricants have more fluctuating tribological properties. In a worldwide round robin test, thirteen different lubricants were compared using six different tribometers. The results revealed significant differences in friction coefficients between lubricants and tribometers. A multiple regression model was used to describe the relationship between the coefficient of friction and tribological loads, and it was successfully validated through a full-forward extrusion process.
CIRP ANNALS-MANUFACTURING TECHNOLOGY
(2023)
Article
Engineering, Chemical
Tyler Salners, John F. Curry, Adam R. Hinkle, Tomas F. Babuska, Nicolas Argibay, Frank W. DelRio, Michael Chandross, Karin Dahmen
Summary: The study found that the friction force of molybdenum disulfide can be characterized as a series of predictable "avalanches", covering a wide range of scales. Both the statistics and dynamics of these avalanches match model predictions, demonstrating a consistent behavior of friction across different scales.
Review
Chemistry, Physical
Muhammad Waqas, Rehan Zahid, Muhammad Usman Bhutta, Zulfiqar Ahmad Khan, Adil Saeed
Summary: The addition of nanoparticles to lubricants at an optimal concentration can result in a lower coefficient of friction. However, there are limitations associated with the use of nanoparticles in lubricants, which can affect their performance. Various nanoparticles, such as CuO, MoS2, and TiO2, have shown promising results in reducing friction within lubricants.
Article
Materials Science, Paper & Wood
Behzad Zakani, Hayder Salem, Sohrab Entezami, Ahmad Sedaghat, Dana Grecov
Summary: Industrial lubricants improve machinery performance by reducing wear and friction between mechanical components. Developing eco-friendly lubricants is crucial for environmental protection. This study investigates the effect of nanoparticle concentration on the lubrication performance of cellulose nanocrystal (CNC) aqueous suspensions, and finds an optimum concentration range under mixed lubrication mode.
Review
Green & Sustainable Science & Technology
Mahdi Khadem, Won-Bin Kang, Dae-Eun Kim
Summary: The use of lubricants in mechanical systems to reduce friction and wear has a long history. However, concerns over the environmental impact of conventional mineral lubricants have led scientists to search for biodegradable alternatives. Despite their lower eco-toxicity, biodegradable lubricants have limitations such as high pour point and poor stability, hindering their full application in various industries. This review aims to introduce different sources and properties of biodegradable lubricants, discuss recent advances in tribology, and explore future trends for improving their tribological properties and overall performance.
INTERNATIONAL JOURNAL OF PRECISION ENGINEERING AND MANUFACTURING-GREEN TECHNOLOGY
(2023)
Article
Materials Science, Multidisciplinary
Qipeng Huang, Xiaoliang Shi, Yawen Xue, Kaipeng Zhang, Chaohua Wu
Summary: This study provides a review of recent progress on designs, properties, and mechanisms of surface texturing and solid lubricants. It discusses the design and processing of surface texture, the type of solid lubricants, and the preparation method of texture combined with lubricants in design strategy. It analyzes the effects of surface texture and solid lubricants on tribological properties, such as antifriction, wear-resistance, and other beneficial effects. It also discusses the synergistic effect mechanisms of surface texture and solid lubricants, focusing on the effects on lubricating coating and the lubrication effect of solid lubricants by texturing. Finally, this review looks forward to the problems and future development of texture and lubricants.
MATERIALS TODAY COMMUNICATIONS
(2023)
Article
Biophysics
Barbara Farias, Saad A. Khan
Summary: Water swellable crosslinked polymers, such as lightly-crosslinked hydrophobically modified polyacrylic acid, are commonly used in oil-in-water emulsions for their thickening properties. The rheological behavior of these polymers in emulsions was studied using small strain amplitude and large amplitude oscillatory shear experiments. The friction coefficient in tribology experiments was found to be dependent on the hydrophobicity of the substrate, polymer, and substrate roughness, providing insights for formulating skincare products with efficient lubrication properties.
COLLOIDS AND SURFACES B-BIOINTERFACES
(2021)
Article
Materials Science, Multidisciplinary
Martin Fenker, Martin Balzer, Sabine Kellner, Tomas Polcar, Andreas Richter, Frank Schmidl, Tomas Vitu
Summary: The MoN-Ag coating system shows potential for industrial applications as a low friction coating at elevated temperatures due to the presence of lubricous molybdenum oxides and silver molybdates. Film hardness is affected by Ag content and bias voltage, with friction coefficients decreasing at high temperatures with increasing Ag content. Raman measurements revealed MoO3 phase on all samples and Ag2Mo4O13 phase for the highest Ag contents.
Article
Engineering, Mechanical
Iryna Slabka, Soeren Henniger, David Kuecuekkaya, Michael Dawoud, Hubert Schwarze
Summary: This study investigated the behavior of greases during oscillating bearing operation and identified parameters that influence the frictional behavior of greases in rolling bearings during oscillating operation at small swivel angles.
Article
Biochemistry & Molecular Biology
Erik Nyberg, Christoph Schneidhofer, Lucia Pisarova, Nicole Doerr, Ichiro Minami
Summary: The study evaluated the performance of P-SiSO in MAC as a lubricant, demonstrating its beneficial lubricating properties in space environments and feasibility as a multifunctional additive.
Article
Engineering, Chemical
Jairo Eduardo Leiva-Mateus, Juan Felipe Santa-Marin, Robison Buitrago-Sierra, Dairo Hernan Mesa Grajales, E. Geffroy
Summary: Friction modifiers play an important role in controlling the traction coefficient. The experimental results show significant differences among different types of friction modifiers in terms of rheological and tribological properties, which can affect their performance. Furthermore, a correlation between rheological behavior and coefficient of traction and retentivity is observed.
LUBRICATION SCIENCE
(2022)
Article
Materials Science, Multidisciplinary
Hari Shankar Vadivel, Marko Bek, Urska Sebenik, Lidija Slemenik Pers, Roland Kadar, Nazanin Emami, Mitjan Kalin
Summary: The study investigates the impact of UHMWPE particle size on its performance, as well as the effect of processing. While minor differences in properties among different grades of UHMWPE were observed, they are not sufficient to definitively determine the influence of particle size and processing on the material's properties and performance.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2021)
Article
Pharmacology & Pharmacy
Devang B. Patel, Rutesh H. Dave
Summary: The study utilized a model formulation to predict the impact of different lubricants on tablet sticking, revealing a decrease in sticking propensity with increased lubricant concentration. By measuring the angles of internal and wall friction, the sticking index of each formulation relative to metal coupons was determined, allowing for the prediction of tablet sticking tendency. The predicted sticking propensity was validated through compression studies, indicating the potential use of the sticking index to predict and modify tablet sticking during compression.
INTERNATIONAL JOURNAL OF PHARMACEUTICS
(2021)
Article
Engineering, Mechanical
Sergey O. Ilyin, Svetlana N. Gorbacheva, Anastasiya Y. Yadykova
Summary: Dispersion of microfibrillated cellulose (MFC) in triethyl citrate is a typical grease with shear-thinning, shear-thickening, and viscoelastic properties. It can maintain its flowability at low temperatures (-50°C), making it potentially applicable as a low-temperature lubricant. Microfibrils reduce friction and wear on steel surfaces by filling irregularities and forming a chromium-enriched friction film.
TRIBOLOGY INTERNATIONAL
(2023)
Article
Biochemistry & Molecular Biology
Antonio M. Borrero-Lopez, Concepcion Valencia, David Ibarra, Ignacio Ballesteros, Jose M. Franco
Summary: This study explores the potential of using lignin-enriched waste products from bioethanol production as thickeners for lubricating greases. The content of lignin and hydroxyl ratio were found to influence the NCO-functionalization and rheological response of the resulting oleogels, with barley straw residues exhibiting the highest storage modulus.
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
(2022)
Article
Polymer Science
Antonio M. Borrero-Lopez, Concepcion Valencia, Jose M. Franco
Summary: This review provides a comprehensive overview of the latest techniques and procedures for treating and modifying lignocellulosic materials to be used as precursors for biomaterials, biochemicals, and biofuels, with a focus on lignin and lignin-based products. Four main pretreatment types, including thermal, mechanical, chemical, and biological, are discussed, with particular attention given to the biological action of fungi and bacteria. The review highlights the vast possibilities of obtaining different final products depending on the selected microorganism and biomass. It extensively describes biofuels, biochemicals, and biomaterials derived from lignocellulose, covering not only the whole lignocellulosic structure but also the main biopolymers, cellulose, hemicellulose, and lignin. Moreover, the formulation of bio-polyurethanes from lignocellulosic materials is emphasized, especially in their applications in lubricant, adhesive, and cushioning material fields. The review also presents high-performance alternatives to petroleum-derived products such as adhesives, lubricating greases, and elastomers with improved properties.
Article
Engineering, Chemical
Adrian Tenorio-Alfonso, M. Carmen Sanchez, Jose M. Franco
Summary: This study evaluated the effect of traditional solvent-based and simplified solvent-free methods on the synthesis of bio-based polyurethane adhesives, and compared their performance with commercial adhesives. The results showed that the inclusion of cellulose acetate improved the performance of polyurethanes, and solvent-free synthesis exhibited good adhesion performance.
INTERNATIONAL JOURNAL OF ADHESION AND ADHESIVES
(2022)
Article
Polymer Science
M. Borrego, J. E. Martin-Alfonso, C. Valencia, M. C. Sanchez, J. M. Franco
Summary: This work focuses on improving the electrospinnability of low-sulfonate lignin/polyvinylpyrrolidone solutions by adding surfactants and studying the resulting nanofibers' ability to structure castor oil. The addition of surfactants improves electrospinnability, producing more compact and uniform fiber mats in certain systems. These nanofiber mats dispersed in castor oil can generate physically stable strong oleogels, which exhibit excellent lubrication performance and potential applications as lubricants.
Article
Engineering, Chemical
Leif Ahme, Erik Kuhn, Miguel Angel Delgado Canto
Summary: One of the key aspects in tribological studies is the investigation of lubrication process using an energetical approach. In this research, the mechanical structural degradation induced by shear stress in lubricating greases was examined, along with the influence of thickener and base oil on the degradation process and mechanical energies. The results shed light on the characteristics and behavior of lubricating greases.
Article
Engineering, Chemical
Isabel Dianez Amores, Joamin Gonzalez-Gutierrez, I. Martinez Garcia, Jose M. Franco, Crispulo Gallegos
Summary: This paper explores the meeting points between Chemical Engineering and 3D printing, as well as the new techniques and applications that could benefit from this collaboration in the future.
CHEMICAL ENGINEERING RESEARCH & DESIGN
(2022)
Article
Agricultural Engineering
J. F. Rubio-Valle, M. C. Sanchez, C. Valencia, J. E. Martin-Alfonso, J. M. Franco
Summary: In this study, electrospun lignin/cellulose acetate fiber-bead nanostructures were developed as structuring agents for vegetable oils to be used as eco-friendly lubricating oleogels. The morphology of the electrospun nanostructures was found to be strongly dependent on the rheological properties of the biopolymer solution. The rheological properties of these gel-like dispersions can be tailored through concentration and ratio, and the resulting oleogels have comparable properties to conventional lubricants.
INDUSTRIAL CROPS AND PRODUCTS
(2022)
Article
Agricultural Engineering
S. D. - Fernandez-Silva, M. A. Delgado, M. V. Ruiz-Mendez, I. Giraldez, M. Garcia-Morales
Summary: This study investigates the feasibility of using waste cooking oils as eco-lubricants and separates them into lighter and heavier fractions through molecular distillation. A comprehensive chemical characterization is conducted, revealing high viscosity index values in waste cooking oils with low polar compounds and acidity levels. It is also found that the lighter fractions composed of free fatty acids demonstrate improved oxidative resistance, while the heavier fractions exhibit better thermal stability. Furthermore, both fractions show enhanced friction-reducing capability compared to their parent waste cooking oils.
INDUSTRIAL CROPS AND PRODUCTS
(2022)
Article
Chemistry, Physical
E. Cortes-Trivino, J. Cubero-Cardoso, A. Tenorio-Alfonso, M. A. Fernandez-Recamales, C. Valencia, J. Urbano, J. M. Franco
Summary: This study investigates the usage of natural deep eutectic solvents (NADESs) with different hydroxyl group content as a matrix base in reactions involving lignin-enriched fraction. The NADESs were prepared by mixing citric acid with glycerol, xylitol, and sucrose as the hydrogen bond donor compounds. Waste lignocellulose was additionally epoxidised to be used as a thickening agent for the NADESs. The research successfully achieved chemical interaction between NADESs and epoxidised lignocellulose, resulting in various rheological responses.
JOURNAL OF MOLECULAR LIQUIDS
(2022)
Article
Materials Science, Multidisciplinary
M. Borrego, J. E. Martin-Alfonso, C. Valencia, Maria del Carmen Sanchez Carrillo, J. M. Franco
Summary: The development of environment-friendly natural polymer gel-like dispersions in oil media, with functional properties, in terms of formulation design and synthesis protocol, is still a cutting-edge research area. This study focuses on the manufacture of electrospun ethylcellulose (EC) nanofibrous webs and their usage as thickeners for vegetable oils. The concentration, molecular weight, and binary solvent systems of EC were found to affect the electrospinnability and rheological properties of the nanofiber dispersions. The morphology of the EC nanofiber web plays a crucial role in their physical stabilization and rheological behavior. This work proposes an innovative approach to produce bio-based oleogel-like dispersions that have potential applications in various sectors.
ACS APPLIED POLYMER MATERIALS
(2022)
Article
Materials Science, Paper & Wood
J. F. Rubio-Valle, C. Valencia, M. Sanchez, J. E. Martin-Alfonso, J. M. Franco
Summary: In this study, electrospun Kraft lignin/cellulose acetate nanostructures were produced and investigated as structuring or thickening agents in castor oil for lubricating applications. The morphology of the electrospun nanofibers was influenced by the rheological properties, electrical conductivity, and surface tension of KL/CA solutions, which were in turn affected by the chemical structure and composition of the Kraft lignins. The resulting oleogels, based on KL/CA electrospun nanostructures, exhibited desirable rheological and tribological properties, making them a promising sustainable alternative to conventional lubricating greases.
Article
Biochemistry & Molecular Biology
Antonio M. Borrero-Lopez, Ling Wang, Haiming Li, Tainise Lourencon, Concepcion Valencia, Jose M. Franco, Orlando J. Rojas
Summary: Acetylated Kraft lignins were used to structure vegetable oils into oleogels. Microwave-assisted acetylation at higher temperatures resulted in gel-like oil dispersions with improved viscoelastic properties and stronger shear-thinning character, along with enhanced long-term stability. The modified lignins enhanced the stability of water-in-oil Pickering emulsions by enhancing hydrogen bonding between the oil and nanoparticles.
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
(2023)
Article
Chemistry, Multidisciplinary
Maria Borrego, Erik Kuhn, Jose E. Martin-Alfonso, Jose M. Franco
Summary: In this study, different lignin nanostructures were obtained through electrospinning and used as thickeners in bio-based lubricating greases. The impact of nanofibrous network morphology on friction and wear was investigated. The results showed that homogeneous bead-free nanofiber mats as thickeners can effectively reduce friction and wear.
Article
Engineering, Environmental
J. F. Rubio-Valle, C. Valencia, M. C. Sanchez, J. E. Martin-Alfonso, J. M. Franco
Summary: This study explores the use of spent coffee grounds and post-consumer PET bottles to produce electrospun composite nanofibers, aiming to develop a new route for upcycling them into high-value oil-based products. By adjusting the ratio of coffee grounds and PET bottles, the properties of the fibers and oleogels can be modified.
RESOURCES CONSERVATION AND RECYCLING
(2023)
Article
Engineering, Environmental
Claudia Roman, Miguel A. Delgado, Samuel D. Fernandez-Silva, Moises Garcia-Morales
Summary: Sustainable lubricating oleogels were obtained by utilizing the high thickening capacity of cellulose nanofibers in castor oil. The effect of pulp bleaching on the thermo-rheological behavior of the oleogels was analyzed, and it was found that oleogels prepared with nanofibers from unbleached pulp performed better under shear deformations and temperature changes, demonstrating a strong capacity for structure recovery.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2022)
