In-situ evaluation of self-healing performance of Engineered Geopolymer Composites (EGC) by ultrasonic method

A recyclable, self-healing conductive nanoclay and corresponding stamping process are developed for printing flexible electronics directly and quickly in situ.

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SELF-HEALING OF WOVEN COMPOSITE LAMINATES VIA IN SITU THERMAL REMENDING

10.12783/asc36/35785 ◽

2021 ◽

Author(s):

ALEXANDER D. SNYDER ◽

ZACHARY J. PHILLIPS ◽

JASON F. PATRICK

Keyword(s):

Composite Laminates ◽

Composite Laminate ◽

Laminated Composites ◽

Reaction Times ◽

Carbon Fiber Composites ◽

Self Healing ◽

Damage Mode ◽

Woven Composite ◽

Internal Damage

Fiber-reinforced polymer composites are attractive structural materials due to their high specific strength/stiffness and excellent corrosion resistance. However, the lack of through-thickness reinforcement in laminated composites creates inherent susceptibility to fiber-matrix debonding, i.e., interlaminar delamination. This internal damage mode has proven difficult to detect and nearly impossible to repair via conventional methods, and therefore, remains a significant factor limiting the reliability of composite laminates in lightweight structures. Thus, novel approaches for mitigation (e.g., self-healing) of this incessant damage mode are of tremendous interest. Self-healing strategies involving sequestration of reactive liquids, i.e. microcapsule and microvascular systems, show promise for the extending service- life of laminated composites. However, limited heal cycles, long reaction times (hours/days), and variable stability of chemical agents under changing environmental conditions remain formidable research challenges. Intrinsic self- healing approaches that utilize reversible bonds in the host material circumvent many of these limitations and offer the potential for unlimited heal cycles. Here we detail the development of an intrinsic self-healing woven composite laminate based on thermally-induced dynamic bond re-association of 3D-printed polymer interlayers. In contrast to prior work, self-repair of the laminate occurs in situ and below the glass-transition temperature of the epoxy matrix, and maintains >85% of the elastic modulus during healing. This new platform has been deployed in both glass and carbon-fiber composites, demonstrating application versatility. Remarkably, up to 20 rapid (minute-scale) self-healing cycles have been achieved with healing efficiencies hovering 100% of the interlayer toughened (4-5x) composite laminate. This latest self-healing advancement exhibits unprecedented potential for perpetual in-service repair along with material multi-functionality (e.g., deicing ability) to meet modern application demands.

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Utilizing in situ alloying reaction to achieve the self-healing, high energy density and cost-effective Li||Sb liquid metal battery

Journal of Power Sources ◽

10.1016/j.jpowsour.2021.230578 ◽

2021 ◽

Vol 514 ◽

pp. 230578

Author(s):

Shuai Yan ◽

Xianbo Zhou ◽

Haomiao Li ◽

Yi Shen ◽

Yaling He ◽

...

Keyword(s):

Energy Density ◽

Liquid Metal ◽

Cost Effective ◽

High Energy ◽

The Self ◽

High Energy Density ◽

Self Healing ◽

Liquid Metal Battery

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Microencapsulation of Liquid Cyanoacrylate via In Situ Polymerization for Self-healing Bone Cement Application – ERRATUM

MRS Proceedings ◽

10.1557/opl.2012.1507 ◽

2012 ◽

Vol 1417 ◽

pp. 1-13

Author(s):

Vineela D. Gandham ◽

Alice B.W. Brochu ◽

William M. Reichert

Keyword(s):

Bone Cement ◽

In Situ Polymerization ◽

Self Healing ◽

Healing Bone

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Discriminatory Analysis of the Ultrasonic Method for the Quality of Pored Cast-in-situ Piles

Structural Materials Technology ◽

10.1201/9781003075844-54 ◽

2020 ◽

pp. 311-316

Author(s):

L. Ruijie ◽

X. Cafflong ◽

M. Shengdong

Keyword(s):

Ultrasonic Method ◽

Discriminatory Analysis

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Soot removal from ancient Egyptian complex painted surfaces using a double network gel: Empirical tests on the ceiling of the sanctuary of Osiris in the temple of Seti I – Abydos

10.21203/rs.3.rs-48526/v1 ◽

2020 ◽

Author(s):

Ehab Awad Al-Emam ◽

Abdel Ghafour Motawea ◽

Joost Caen ◽

Koen Janssens

Keyword(s):

Self Healing ◽

Wall Paintings ◽

Shape Stability ◽

Double Network ◽

Ancient Egyptian ◽

Third Phase ◽

Digital Microscope ◽

Seti I ◽

The Temple

Abstract In this study, we evaluated the ease of removal of soot layers from ancient wall paintings by employing double network gels as a controllable cleaning method. The ceiling of the temple of Seti I (Abydos, Egypt) is covered with thick layers of soot; this is especially the case in the sanctuary of Osiris. These layers may have been accumulated during the occupation of the temple by Christians, fleeing the Romans in the first centuries A.D.. Soot particulates are one of the most common deposits to be removed during conservation-restoration activities of (Egyptian) wall paintings. They usually mask the painted reliefs and reduce the permeability of the painted surface. A Polyvinyl alcohol-borax/agarose (PVA-B/AG) double network gel was selected for this task since its properties were expected to be compatible with the cleaning treatment requirements. The gel is characterized by its flexibility, permitting to take the shape of the reliefs, while also having self-healing properties, featuring shape stability and an appropriate capacity to retain liquid. The gel was loaded with several cleaning reagents that proved to be effective for soot removal. Two sets of soot removal tests were conducted with these gel composites. The cleaned surfaces were examined in situ with the naked eye and with a digital microscope in order to select the best gel composite. The gel composite, loaded with a solution of 5% ammonia, 0.3% ammonium carbonate, and 0.3% EDTA yielded the most satisfactory results and allowed to safely remove a crust of thick soot particles from the surface. Thus, during a third phase of the study, it was used successfully to clean a larger area of the ceiling.

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MULTI-WAVE ULTRASONIC CONTROL OF CONCRETE

Science & Technique ◽

10.21122/2227-1031-2017-16-4-289-297 ◽

2017 ◽

Vol 16 (4) ◽

pp. 289-297

Author(s):

D. Yu. Snezgkov ◽

S. N. Leonovich

Keyword(s):

Rayleigh Wave ◽

Pulse Propagation ◽

Ultrasonic Method ◽

Physical And Mechanical Properties ◽

Pulse Velocity ◽

Energy Localization ◽

Near Surface ◽

In Situ Conditions ◽

Selection Of

The existing non-destructive testing system of structure concrete is actually orientated on the usage of longitudinal acoustical waves. This is due to simplicity of technical realization for measuring velocity (time) of acoustical pulse propagation in bulk concrete. But a reverse side of simple measuring procedure is a loss of additional information on concrete which is contained in the accepted acoustical signal. Therefore usage of an ultrasonic concrete testing method is limited by assessment of its strength. Joint usage of several wave types, so-called multi-wave testing, allows to refine metrology parameters of the ultrasonic method and to gain more information while determining physical and mechanical properties of concrete in laboratory and in situ conditions. The paper considers testing of elongated concrete elements and structures by an ultrasonic pulsing method on the basis of longitudinal subsurface and Rayleigh waves. It has been proposed to use methodology for time selection of wave components according to amplitude parameter and it has been applied for standard acoustical transformers with considerable reverberation time and not possessing spatial selectivity Basic principle of the proposed methodology is visual (according to oscillogram of the received signal) determination of characteristic time moments which are used for calculation of differential value of a propagation velocity in the Rayleigh wave impulse. The paper presents results pertaining to simulation of acoustical pulse propagation on the basis of 0.15 m and data of concrete ultrasonic in situ testing on measuring bases from 0.25 to 1.75 m. Advantage of large baseline for sonic test is a possibility for execution of a hundred percent inspection for surface of large-sized elements and structures, and so there is no need to make a selective inspection in some control areas as it is stipulated by provided by existing regulations. Responsivity of the Rayleigh wave parameters to near surface concrete defects permits quickly and efficiently to detect crack areas in a reinforced structure. Energy localization of a surface wave in a layer having width λ/2–λ provides a possibility to ignore reinforcement availability under appropriate selection of oscillation frequency. In addition to this, large measuring baseline makes it possible to lower effect of concrete structural inhomogeneity on statistical stability for pulse velocity assessment that ultimately reveals a possibility to register an appearance of concrete acoustical elasticity effect under in situ conditions.

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