scholarly journals Constructing a biomimetic robust bi-layered hydrophilic lubrication coating on surface of silicone elastomer

Friction ◽  
2021 ◽  
Author(s):  
Luyao Gao ◽  
Xiaoduo Zhao ◽  
Shuanhong Ma ◽  
Zhengfeng Ma ◽  
Meirong Cai ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Composite Layer ◽  
High Load ◽  
Silicone Elastomer ◽  
Aqueous Lubrication ◽  
Low Friction ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Lubrication Performance ◽  
Wide Range

AbstractSilicone elastomers-based materials have been extensively involved in the field of biomedical devices, while their use is extremely restricted due to the poor surface lubricity and inherent hydrophobicity. This paper describes a novel strategy for generating a robust layered soft matter lubrication coating on the surface of the polydimethylsiloxane (PDMS) silicone elastomer, by entangling thick polyzwitterionic polyelectrolyte brush of poly (sulfobetaine methacrylate) (PSBMA) into the sub-surface of the initiator-embedded stiff hydrogel coating layer of P(AAm-co-AA-co-HEMA-Br)/Fe, to achieve a unified low friction and high load-bearing properties. Meanwhile, the stiff hydrogel layer with controllable thickness is covalently anchored on the surface of PDMS by adding iron powder to provide catalytic sites through surface catalytically initiated radical polymerization (SCIRP) method and provides high load-bearing capacity, while the topmost brush/hydrogel composite layer is highly effective for aqueous lubrication. Their synergy effects are capable of attaining low friction coefficient (COFs) under wide range of loaded condition in water environment with steel ball as sliding pair. Furthermore, the influence of mechanical modulus of the stiff hydrogel layer on the lubrication performance of layered coating is investigated, for which the COF is the lowest only when the modulus of the stiff hydrogel layer well matches the PDMS substrate. Surprisingly, the COF of the modified PDMS could remain low friction (COF < 0.05) stably after encountering 50,000 sliding cycles under 10 N load. Finally, the surface wear characterizations prove the robustness of the layered lubricating coating. This work provides a new route for engineering lubricious silicon elastomer with low friction, high load-bearing capacity, and considerable durability.

scholarly journals Synergies in lubrication

2017 ◽  
Vol 19 (35) ◽  
pp. 23677-23689 ◽  
Author(s):  
Andra Dėdinaitė ◽  
Per M. Claesson
Keyword(s):  
Bearing Capacity ◽  
Aqueous Medium ◽  
Water Layer ◽  
High Load ◽  
Low Friction ◽  
Load Bearing Capacity ◽  
Friction Forces ◽  
Load Bearing ◽  
Living Organisms

In living organisms the aqueous medium is used for providing low friction forces. This is achieved by synergistic actions of different biomolecules that together accomplish a high load bearing capacity and sustain an easily sheared water layer.

scholarly journals Low friction and high load bearing capacity layers formed by cationic-block-non-ionic bottle-brush copolymers in aqueous media

Soft Matter ◽  
2013 ◽  
Vol 9 (22) ◽  
pp. 5361 ◽  
Author(s):  
Xiaoyan Liu ◽  
Esben Thormann ◽  
Andra Dedinaite ◽  
Mark Rutland ◽  
Ceslav Visnevskij ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Aqueous Media ◽  
High Load ◽  
Low Friction ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Bottle Brush

Continuously Growing Ultrathick CrN Coating to Achieve High Load-Bearing Capacity and Good Tribological Property

2018 ◽  
Vol 10 (3) ◽  
pp. 2965-2975 ◽  
Author(s):  
Zechao Li ◽  
Yongxin Wang ◽  
Xiaoying Cheng ◽  
Zhixiang Zeng ◽  
Jinlong Li ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Tribological Property ◽  
High Load ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Crn Coating

scholarly journals Modulation of kinesin’s load-bearing capacity by force geometry and the microtubule track

2019 ◽  
Author(s):  
Serapion Pyrpassopoulos ◽  
Henry Shuman ◽  
E. Michael Ostap
Keyword(s):  
Cell Division ◽  
Bearing Capacity ◽  
Organelle Transport ◽  
Vertical Force ◽  
Long Distance ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Wide Range ◽  
Single Bead ◽  
Attachment Duration

AbstractKinesin motors and their associated microtubule tracks are essential for long-distance transport of cellular cargos. Intracellular activity and proper recruitment of kinesins is regulated by biochemical signaling, cargo adaptors, microtubule associated proteins and mechanical forces. In this study, we found that the effect of opposing forces on the kinesin-microtubule attachment duration depends strongly on experimental assay geometry. Using optical tweezers and the conventional single-bead assay we show that detachment of kinesin from the microtubule is likely accelerated by forces vertical to the long-axis of the microtubule due to contact of the single bead with the underlying surface. We used the three-bead assay to minimize the vertical force component and found that when the opposing forces are mainly parallel to the microtubule the median attachment duration between kinesin and microtubules can be up to 10-fold longer than observed using the single-bead assay. Using the three-bead assay, we also found that not all microtubule protofilaments are equivalent interacting substrates for kinesin and that the median attachment duration (median-Δt) of kinesin varies by more than 10-fold, depending on the relative angular position of the forces along the circumference of the microtubule. Thus, depending on the geometry of forces across the microtubule, kinesin can switch from a fast detaching motor (median-Δt < 0.2 s) to a persistent motor that sustains attachment (median-Δt > 3 s) at high forces (5 pN). Our data show that the load-bearing capacity of the kinesin motor is highly variable and can be dramatically affected by off-axis forces and forces across the microtubule lattice which has implications for a range of cellular activities including cell division and organelle transport.Significance StatementKinesins are cytoskeletal motors responsible for the transport of cargoes along microtubules. It is well known that opposing forces decrease kinesin’s speed and run length. In this study, we found that when the pair of opposing forces applied on the kinesin-microtubule complex are parallel to the microtubule, the ability of kinesin to remain attached to the microtubule can vary by more than an order of magnitude depending on the relative azimuthal position of the pair of forces along the periphery of the microtubule. These results reveal a previously unknown versatility of kinesin’s load bearing capacity and as such have implications for the potential physiological roles of kinesin in a wide range of cell activities, including organelle transport and cell division.

scholarly journals INVESTIGATIONS IN THE STRENGTH OF GLULAM MULTILAYERED BEAMS UNDER A SHORT-TIME SHEAR/MEDINIŲ KLIJUOTŲ DAUGIASLUOKSNIŲ SIJŲ STIPRUMO TYRIMAI VEIKIANT TRUMPALAIKĖMS SKERSINĖMS SKERSINĖMS JĖGOMS

1998 ◽  
Vol 4 (1) ◽  
pp. 5-11
Author(s):  
Rimantas Čechavičius
Keyword(s):  
Bearing Capacity ◽  
Load Bearing Capacity ◽  
Lateral Direction ◽  
Load Bearing ◽  
Prestressing Force ◽  
Lateral Tension ◽  
Wide Range ◽  
Wood Fibres ◽  
Comparison Of The Results ◽  
Short Time

The author of the article has performed wide-range tests of glulam beams. The objective of the tests is increasing of load bearing capacity of such beams under shear. As a result 5 inventions have been suggested and confirmed. In total 44 beams of various types were tested under the action of short and long-time loadings. These investigations have verified a new method for increasing load bearing capacity of glulam beams. The essence of the method was the utilisation of prestressed elements in multilayered beams. It allows to increase load bearing capacity of such elements under shear and decrease or eliminate the influence of lateral tension stresses on their resistance. Totally, 30 beams have been tested for the influence of short-time forces: 6 of them are multilayered with pre-stressed elements, made by the offer of invention No 954237; 8 analogous beams for comparison of the results are made of squared timber, board package, multilayered without prestressed elements; 16 different beams for additional investigations of methods of experiments and closer definition of separate technological factors. All beams failed because of shear. It has been proved by experiments that plywood brass in multilayered beams not only increases the strength of the beam, but also prevents the element from a sudden failure, increases its reliability. Longitudinal cracks have appeared in the zones of neutral axes of prestressed multilayered beams before the failure of them, while the load was 0,93–0,98 of ultimate the width of the crack was 0,7–0,8 mm, and the shear deformation was 2–6 mm at the moment of failure. The strength of the beams under short-time shear depending on the level of prestressing force (σy = = 1,5…2,25 MPa) increased 9–10% and crack resistance increased 9–22% in comparison with unpresstressed beams. A short description of invention No 954237 has also been given (see Fig 6). Layers of a load bearing multilayered element with wood fibres oriented along the axis of the member (1) are precompressed laterally to the wood fibres (5). Compression force should not cause stresses (σy) higher than the point of wood proportionality in lateral direction. These layers (1) are glued with the layers where wood fibres are directed laterally to the axis of the element (2) and they are shorter in value Δ ≥ σy · h/E90 than layers (1). Horizontal prestressing of multilayered element (4) has to ensure a qualitative cohesion. It is possible to use structural plywood instead of wood layers with fibres lateral to the axis of the element. The use of this method does not only increase the resistance of glulam elements to short-time shear, but also ensures a better reliability of such structures.

Interlayer design for the graphite-like carbon film with high load-bearing capacity under sliding-friction condition in water

2014 ◽  
Vol 311 ◽  
pp. 816-824 ◽  
Author(s):  
Yongxin Wang ◽  
Jibin Pu ◽  
Jiafan Wang ◽  
Jinlong Li ◽  
Jianmin Chen ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Sliding Friction ◽  
Carbon Film ◽  
Friction Condition ◽  
High Load ◽  
Load Bearing Capacity ◽  
Load Bearing

Aqueous lubrication of poly(N-hydroxyethyl acrylamide) brushes: a strategy for their enhanced load bearing capacity and wear resistance

RSC Advances ◽  
2016 ◽  
Vol 6 (26) ◽  
pp. 21961-21968 ◽  
Author(s):  
Jingjing Zhang ◽  
Shengwei Xiao ◽  
Mingxue Shen ◽  
Li Sun ◽  
Feng Chen ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Friction Coefficient ◽  
Bearing Capacity ◽  
Surface Friction ◽  
Aqueous Lubrication ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Aqueous Surface

Poly(N-hydroxylethyl acrylamide) brushes show a very low aqueous surface friction coefficient. Crosslinking of these brushes increases the surface friction coefficient, but can significantly enhance their load bearing capacity and wear resistance.

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