Elastic Recovery Rate Research Articles

Preparation of multi-axial compressible 3D PVDF nanofibre/graphene wearable composites sensor sponge and application of integrated sensor

Compared with piezoelectric and capacitive sensor devices, piezoresistive sensor devices have a simple preparation process and good sensing performance, and are the most widely used in flexible strain sensing. The sensing performance of piezoresistive flexible strain sensors is usually characterized by parameters such as sensitivity, sensing range and durability. The development of piezoresistive sensor devices with multiple excellent properties at the same time is the current research hotspot. In this study, a PVDF nanofibre/graphene multiaxial compressible composites sponge sensor was prepared by combining nanotechnology with a freeze-drying method, and then integrated bridge circuit devices through multiple sensing sponges. The sensor device prepared in this study is a multifunctional wearable device with high sensitivity, wide sensing range and good durability. Results show that the addition of excessive graphene significantly improves the pore morphology, in which it is a cube porous with a uniform size. The thicker porous wall formed by the entanglement of graphene sheets improves the mechanical strength of the sensor. The sponge sensor also has excellent elasticity, whilst the elastic recovery rate can be as high as 90% when the compression reaches more than 80%. When compressed in different directions, it has a wide sensing range, whilst the resistance change rate can be from 110% to 0.5%, all of which are regular wave curves. The bridge circuit integrated device of multiple sensing sponges obviously improves the overall sensitivity of the sensor under the same compression ratio, the compression ratio is reduced and the service life is increased. This conclusion lays a research foundation for the application of multi-module piezoresistive sensor integration in the field of smart wearables.

Synthesis of Thermoplastic Polyurethanes Containing Bio-Based Polyester Polyol and Their Fiber Property.

Among the starting materials of thermoplastic polyurethanes (TPUs), it was confirmed that succinic acid-based polyester biopolyols having different molecular weights (Mn = 1000, 2000, and 4000) affect the physicochemical properties of the final polymer significantly. Bio-TPUs synthesized through a solvent-free one-shot polymerization process were synthesized with a polyester polyol, 1,4 butanediol (BDO), and 4,4′-methylene diphenyl diisocyanate (MDI) in a molar ratio of 1:1:2. As a control group, one typical petroleum-based TPU was synthesized and characterized along with other bio-based TPUs. Representative petroleum-based and bio-based TPUs synthesized were manufactured as monofilaments with a diameter of about 0.2 mm through an extrusion process with different draw ratios (4, 5, and 6 times). The molecular weight and structural properties of the TPUs were characterized by GPC and FT-IR analysis and thermal characterization by DSC and TGA analysis. Petroleum-based TPU and bio-based TPU having the same molecular weight soft segment (SS) tended to have similar molecular weight and hard segment (HS) content. TPUs with high HS content had excellent thermal stability, enabling stable extrusion of TPUs. In addition, it was confirmed that the bio-based TPU fibers produced in this way had a tensile strength corresponding to the physical properties of petroleum-based TPU fibers and an excellent elastic recovery rate of almost 100 %. These results indicate the application potential of bio-TPU.

Effect of temperature on the properties of polymer cement composite material

AbstractIn the actual working environment for the polymer cement composite, the effect of temperature on its properties cannot be ignored. In order to investigate the properties of polymer cement composite in extreme temperature environment, this study conducted bond test, tensile test, and shear test of composites at different temperatures (−30, −15, 25, 40, and 60°C). Through measuring the elastic recovery rate of specimens, as well as relevant strength indexes, deformation indexes and energy consumption indexes under tensile and shear loads, the effect of temperature on the bond property, tensile property, and shear property of the composite were investigated. The results show that the polymer cement composite has a good bond property, and no damage occurs at any temperature or after cold drawing and hot pressing cycle. Temperature has a great influence on the tensile property and shear property of polymer cement composite. At a low temperature, the tensile property and shear property improve, the strength and energy consumption indexes increase noticeably, and the elongation at break increases while the peak strain reduces in terms of deformation indexes. At a high temperature, the tensile property and shear property deteriorate, and the strength, deformation, and energy consumption indexes all fall. As a result, the polymer cement composite is more suitable for cold areas.

Mapping of microstructure features and micromechanical properties of Ti–xAl–yFe (x=0–6, y=4–10 wt.%) alloys via diffusion couple method

In this work, a diffusion couple of Ti–6Al–4Fe/Ti–10Fe (wt. %) was fabricated and heat-treated under BASCA (β-annealing, slow cooling, and aging) processing conditions to facilitate the strengthening and toughening design for low-cost titanium alloys. Assisted by Scanning Electron Microscopy (SEM), Electron Probe Micro analyses (EPMA), and nanoindentation, a picture was constructed to map the composition-dependent microstructure features and micromechanical properties in the composition array of Ti–(0–6)Al–(10–4)Fe (wt. %). The reduction of Al and the enrichment of Fe resulted in the α lamellae in finer appearance and less amount, indicating that the alloys with the same chemical composition as that in the micro-areas would show similar microstructure features. The elastic modulus E obtained from nanoindentation exhibited a decreasing trend with Al impoverishment which was in contrast to a slight increase of nanohardness H. The measured elastic modulus and nanohardness enabled evaluations of wear resistance (H/E), resistance to plastic deformation (H3/E2), elastic recovery rate (Ue/Ut), and plasticity index (Up/Ut) in the micro-areas which served as the property indices analogous to those of the independent alloys with the same chemical compositions. The indices varied monotonously in the composition array. The highest H/E, H3/E2, Ue/Ut and the lowest Up/Ut was discovered at Ti–10Fe terminal, indicating good wear resistance and longer service potentials. Nevertheless, the high modulus E = 145.76 GPa of Ti–4.96Al–4.43Fe is promising in the ballistic application.

Influence of sliding velocity on microscratch response of carbohydrate polymers by Berkovich indenter

Microscratch tests were carried out on polyamide (PA) and polypropylene (PP) by Berkovich indenter to study influence of sliding velocity on microscratch response of carbohydrate polymers. Both penetration depth and residual depth decrease nonlinearly with the increase of sliding velocity. Elastic deformation is dominant in the total deformation during scratching of polymers. Both residual and contact scratch widths decrease nonlinearly with sliding velocity. The elastic recovery rate increases with sliding velocity. Both scratch hardness and lateral hardness increase nonlinearly with sliding velocity. Scratch hardness also increases nonlinearly with the increase of strain rate due to strain rate hardening effect. Scratch friction coefficient of PA decreases with increasing sliding velocities, and can be regarded to be constant under large sliding velocities. Nevertheless, scratch friction coefficient of PP increases with sliding velocity. Residual scratch grooves, scratch friction coefficient, and lateral force under different sliding velocities can be used to reveal the different friction mechanisms of PA and PP.

Influence of core yarn structure and yarn count on yarn elastic properties

This work aims to compare the effects of different yarn structures on the elastic properties. A new type of elastic core-spun yarn which is called tri-core (elastane/T400/elastane) yarn is introduced and tested for elastic properties after cyclic loading. The other yarn structures used are single-core/T400, single-core/lycra, dual-core (elastane/T400) yarn, and yarn without a core component (conventional). The five types of yarn structure were produced at three levels of yarn counts (10, 14, and 18 Ne). Elastic properties after cyclic loading including stress decay, permanent deformation, elastic recovery, and relaxation rate were calculated and statistically analyzed using two-way analysis of variance. The scanning electron microscopy images of the five structures used were produced to illustrate the structure of these yarns. The results determined that elastane/T400/elastane core-spun and single-core/T400 yarns have higher values for most of the elastic properties. It was found that yarn count and yarn structure significantly affect stress decay, while the yarn structure significantly affects permanent deformation and elastic recovery. On the other hand, yarn count significantly affects the relaxation rate. Data showed that the number of cyclic tests significantly influences yarn elastic recovery.

Evaluation of mechanical properties of poly(L‐lactic acid) braided stents with axial stiffeners

AbstractPoly(l‐lactic acid) (PLLA) has been widely used in constructing biodegradable braided stents due to high biocompatibility and biodegradability. However, poor mechanical properties of this stent are main weaknesses. In this paper, the mechanical properties of PLLA braided stents containing axial stiffeners were evaluated. The stents with stiffener diameters of 0.11, 0.19 and 0.28 mm are named SS11, SS19 and SS28, respectively, and the stent without stiffener is named SS00 as control. The results show that compared with SS00, the bending stiffness of SS11, SS19 and SS28 is increased by 0.77, 1.76, and 2.70 times, respectively. Meanwhile, chronic outward force at an indicated use diameter of 5 mm is increased by 0.83, 0.50, and 0.21 times, but elastic recovery rate is decreased by 5.6%, 14.6%, 22.5%. In addition, radial stiffness of SS11, SS19, and SS28 are increased by 2.81, 2.08 and 1.62 times, respectively. Therefore, the radial support performance is improved and the bending flexibility is weakened by adding stiffeners. Taken together, SS11 can provide sufficient radial support force and low axial force in clinical applications. This study may provide a reference for optimizing the mechanical properties of the biodegradable braided stents.

Mechanical properties and indentation-induced phase transformation in 4H–SiC implanted by hydrogen ions

This paper aims to improve machining efficiency, suppress surface cracking, and reduce subsurface damage of silicon carbide (SiC). Hydrogen ions were implanted into SiC to study mechanical properties at nano and macro scales. Nanoindentation experiments were conducted using a Berkovich indenter. Firstly, the effect of ion implantation on the load-displacement curves at different indentation depths was investigated using molecular dynamics (MD) simulations. Elastic-plasticity at nanoscale was analyzed, and the values of material properties were obtained. Secondly, variability of surface morphology, phase transformation, and coordination number induced by nanoindentation with and without ion implantation was evaluated. Although ion implantation induced damage to the SiC model, the damage after nanoindentation was lower than that without ion implantation. Additionally, nanoindentation experiments were performed for small loads and high loads, respectively. The small load experiments were employed to derive material properties of the ion-implanted SiC. Improvement mechanisms of ion implantation on crack extension, fracture toughness, and elastic recovery rate were investigated under the high-load experiments. The results indicate that the amorphous structure induced by ion implantation can successfully prevent crack propagation and improve fracture toughness. The modification technology of SiC by ion implantation significantly improves the machining efficiency and the non-damage of its surface and subsurface.

Wood-based micro-spring composite elastic material with excellent electrochemical performance, high elasticity and elastic recovery rate applied in supercapacitors and sensors

Due to its natural and rich porous structure, biomass wood-based materials have potential applications in electronic devices such as supercapacitors and sensors, which is also in line with the concept of green and sustainable development and has attracted extensive attention of more and more researchers. However, due to the poor conductivity of wood-based materials, in order to enhance their conductivity, they have to be carbonized or compounded with other materials with good conductivity. Here, we first synthesized the rGO-LiOH/wood micro-spring composite with high strength, high specific capacitance, high elasticity and elastic recovery rate via vacuum suction and carbonization. The as-obtained wood-based hybrid is applied to supercapacitors and sensors, and shows good supercapacitance and sensing characteristics. Under a scan rate of 200 mV s−1, the specific capacitance is 352 F g−1, the energy density is 48.89 Wh kg−1, the power density reaches 9780 W kg−1, and the capacitance retention still maintains at 98% (346 F g−1) after experiencing 1000 cycles, showing excellent energy storage and working stability. More importantly, the composite still shows stable energy storage effect under repeated compression rebound conditions. After 5000 compression-recovery, a high elastic recovery rate of 91.67% and high capacitance retention of approximately 80% are still obtained. These outstanding properties highlight the great application potential of the rGO-LiOH/wood micro-spring composite in biomass based wearable electronics, portable power supply equipment and sensors.

Preparation and characterization of CQDs/SBS composites and its application performance as asphalt modifier

This research aims to use the prepared bio-base carbon quantum dots/styrene–butadiene styrene block copolymer (CQDs/SBS) composite materials as asphalt modifiers based on Pickering emulsion polymerization. The physical and chemical properties of CQDs/SBS composite modifier and its effect on asphalt modification were researched and contrasted it with SBS modifier. The results show that strong van der Waals forces and chemical covalent bonds are formed between CQDs and SBS polymer chains through a series of physicochemical reactions, resulting in strong interactions. Thus CQDs are uniformly dispersed in the SBS phase to form a homogeneous composite material. With the addition of CQDs, the CQDs/SBS composite modifier with slightly lower molecular weight than SBS modifier and can be better dispersed in asphalt. In addition, CQDs/SBS composite modifier has better thermal stability. Furthermore, CQDs and SBS have a synergistic impact in progressing the high-temperature property of polymer modified asphalt (PMA), which is showed by the improvement in softening point, viscosity, rutting resistance, and elastic recovery rate of CQDs/SBS PMA. However, the low-temperature property of CQDs/SBS PMA decreased, which is manifested by decreased penetration and ductility, increased creep stiffness modulus (S), and decreased the rate of change of stiffness with time (m). Further, CQDs/SBS PMA appears superior better storage stability than SBS PMA. It has the preferences of facile preparation procedure and low cost too, making it a beneficial choice for asphalt modifiers.

Superior Hard but Quickly Reversible Si-O-Si Network Enables Scalable Fabrication of Transparent, Self-Healing, Robust, and Programmable Multifunctional Nanocomposite Coatings.

A coating with programmable multifunctionality based on application requirements is desirable. However, it is still a challenge to prepare a hard and flexible coating with a quick self-healing ability. Here, a hard but reversible Si-O-Si network enabled by aminopropyl-functionalized poly(silsesquioxane) and triethylamine (TEA) was developed. On the basis of this Si-O-Si network, basic coatings with excellent transparency, hardness, flexibility, and quick self-healing properties can be prepared by filling soft polymeric micelles into hard poly(silsesquioxane) networks. The highly cross-linked continuous network endows the coating with a hardness (H = 0.83 GPa) higher than those of most polymers (H < 0.3 GPa), while the uniformly dispersed micelles decrease the Young's modulus (E = 5.89 GPa) to a value as low as that of common plastics, resulting in excellent hardness and flexibility, with an H/E of 14.1% and an elastic recovery rate (We) of 86.3%. Scratches (∼50 μm) on the coating can be healed within 4 min. The hybrid composition of poly(silsesquioxane) networks also shows great advantages in integration with other functional components to realize programmable multifunctionality without diminishing the basic properties. This nanocomposite design provides a route toward the preparation of materials with excellent comprehensive functions without trade-offs between these properties.

Phase Change Energy Storage Elastic Fiber: A Simple Route to Personal Thermal Management.

A novel thermoplastic polyurethane (TPU) PCFs possessing a high loaded ratio and high elasticity was simply prepared by vacuum absorption following wet spinning, then coated by waterborne polyurethane (WPU). Octadecane (OCC), hexadecanol (HEO), and stearic acid (SA), which have different tendencies to form hydrogen bonds with TPU, were selected as PCMs, and their thermal behavior, thermal storge properties, and elasticity were systematically studied, respectively. The hierarchical pore structure though from the sheath to the core part of TPU filaments weakened the influence of the nonfreezing layer and hydrogen bond on the crystallization behavior of PCMs. The resulting HEO/TPU fiber has the highest enthalpy of 208.1 J/g compared with OCC and SA. Moreover, the HEO/TPU fiber has an elongation at break of 354.8% when the phase change enthalpy is as high as 177.8 J/g and the phase change enthalpy is still 174.5 J/g after fifty cycles. After ten tensile recovery cycles, the elastic recovery rate of HEO/TPU fiber was only 71.3%. When the HEO in the fiber was liquid state, the elastic recovery rate of HEO/TPU fiber promoted to 91.6%. This elastic PCFs have excellent thermal cycle stability, elastic recovery, and temperature sensitivity. It has great application potential in the fields of flexible wearable devices, intelligent fabrics, and temperature sensors.

Formation and beneficial effects of the amorphous/nanocrystalline phase in laser remelted (FeCoCrNi)75Nb10B8Si7 high-entropy alloy coatings fabricated by plasma cladding

High-entropy amorphous composite coatings have high potential application value in the industrial field due to their excellent performance. (FeCoCrNi)75Nb10B8Si7 high-entropy alloy coatings with amorphous/nanocrystalline phases were prepared by plasma cladding and subsequent laser remelting. The phase, microstructure, mechanical properties, and wear resistance of the coatings were studied. Detailed characterization indicated that the microstructure of the plasma cladding coating consisted of the body-centered cubic (BCC) phase, whereas that of the laser remelting coatings consisted of the Fe and Ni-rich BCC phase in the dendritic area and the Nb, B, and Si-rich nanocrystalline-face-centered cubic (nano-FCC) + amorphous phases in the interdendritic area. Excellent mechanical properties were observed, including high microhardness, high nanohardness (H) to elastic modulus (E) ratio (H/E), high H3/E2, and a high elastic recovery rate (η). Furthermore, the coefficient of friction (COF) was lower in the laser remelting coatings (0.6) than in the plasma cladding coating (0.7), which was attributed to severe adhesive wear of the plasma cladding coating and abrasive and slightly adhesive wear of the laser remelting coatings. The microstructure evolution and strengthening contribution of the interdendritic structure in the laser remelting coatings and the relationship between the microstructure and mechanical properties and wear resistance were analyzed.

Comparative analysis of mechanical properties for mono and poly-crystalline copper under nanoindentation – Insights from molecular dynamics simulations

Crystallographic orientation and grain size for monocrystalline and polycrystalline materials respectively play a critical role in defining their mechanical behaviour under nanoindentation. To understand their effects on mechanical properties, molecular dynamics (MD) simulations help in revealing the underlying physical phenomena governing the nanoindentation behaviour. This paper attempts to comparatively analyse and study the effects of crystallographic orientations of monocrystalline copper {(100), (110) and (111)} and critical grain size of polycrystalline copper on the nanoindentation response using MD simulations. The results obtained for indentation load vs. depth curve, hardness, dislocations, and elastic recovery were analysed for comparison. Cu(111) exhibited an average hardness of 12.62 GPa, which is 18.27% more than that of Cupoly. The pile-ups of 8 Å size were observed in Cupoly; and this was higher than any of copper system studied here. The dislocation extraction algorithm (DXA) analysis revealed that the total dislocations in Cu(111) was 34.23% and 153.8% lower than that of Cu(110) and Cupoly, respectively. Cu(111) comprised of highest Stair-rod dislocation along with LC and Hirth locks. Furthermore, a prismatic loop comprised of sessile dislocations also appeared in Cu(111). The elastic depth recovery rate for Cu(100) was 52.75%, 41.60% and 40.66% higher than that of Cu(110), Cu(111) and Cupoly, respectively. This study revealed that the nanoindentation based mechanical performances of monocrystalline copper systems, specifically Cu(111) were superior to any other copper systems.

Preparation and performance evaluation of emulsified asphalt with rejuvenator and latex for pavement seal coat

With the rapid growth of transportation, the requirement of emulsified asphalt (EA) for seal coat changed from singular performance to comprehensive performance. To increase the function of EA, the rejuvenator was added to endow the possibility to rehabilitate deteriorated asphalt pavement, and the latex was included to guarantee the performance of EA. The study aims at investigating the effect of adding rejuvenator and latex in EA. Therefore, EA containing rejuvenator (three content levels) and latex for pavement seal coat was prepared and its performance was evaluated. Based on the investigation of the effect of rejuvenator on its technical performance, an appropriate formula of modified EA with moderate viscosity and excellent performance was selected. Then, the high- and low-temperature and fatigue resistance performance of the evaporation residue of the appropriate modified EA as well as a SBS-modified asphalt and base asphalt binder were evaluated by dynamic shear rheometer and bending beam rheometer. Based on the results, it was found that the addition of rejuvenator and latex had significantly increased the saybolt viscosity, which was desirable for adhesion of EA. With the rejuvenator content increased from 2% to 5%, the saybolt viscosity of modified EA gradually decreased since the rejuvenator reduced the internal friction. The types of emulsifier had no significant effect on this evolution. The storage stability of EA improved noticeably with the addition of rejuvenator and latex (concentration difference decreased from 21.3% to 85.1%). The types of emulsifier would affect the variation of storage stability with increasing rejuvenator content. All the modified EA had higher solid content, penetration, and elastic recovery rate than the normal EA. The penetrations of modified EA were more susceptible to the content of rejuvenator, whereas the solid contents and elastic recovery ratios were almost independent of the rejuvenator content. Results also reveal that among the modified EA evaporation residue, SBS-modified asphalt and base asphalt binder, the modified EA evaporation residue had the longest fatigue life and the comparable low-temperature performance with SBS-modified asphalt. However, it had the poorest high-temperature performance for all the three binders. Therefore, it can be said that the modified EA with rejuvenator and latex has feasibility and potential, which will provide theoretical foreshadowing for application of the modified EA on deteriorated asphalt pavement.

UV-resistant transparent lignin-based polyurethane elastomer with repeatable processing performance

Lignin, as a green and environmentally sustainable natural material, is indispensable to be reasonably developed and utilized. Herein, lignin macromolecules are used as raw materials of polyhydroxyl structure to synthesize polyurethane macromolecules. It is found that the optimal mass ratio of lignin to isocyanate group in the synthesis of polyurethane is 95/5. The lignin-based polyurethane putted the lignin as a fulcrum to form a hydrogen bond with the polyurethane macromolecular chain to form a hydrogen bond network structure, so that its elastic recovery rate attains 94.7%. Meanwhile, its tensile strength and breaking elongation rate reach 16.2 MPa and 1049.5% respectively. Furthermore, the lignin-based polyurethane synthesized in this work still maintain excellent mechanical properties after thermal reprocessing. Moreover, the lignin-based polyurethanes prepared by this approach also possess excellent transparency and UV resistance, and the average ultraviolet protection factor (UPF)value of the lignin-based polyurethane hot-pressed fabrics obtained by hot pressing is greater than 50. This work provides an innovative and sustainable strategy for the further application of lignin, a pure natural material, as a bio-based multifunctional additive to packaging, textiles, automotive trim and other fields.

Phase transformation and subsurface damage formation in the ultrafine machining process of a diamond substrate through atomistic simulation

This report explores the effects of machining depth, velocity, temperature, multi-machining, and grain size on the tribological properties of a diamond substrate. The results show that the appearance of graphite atoms can assist the machining process as it reduces the force. Moreover, the number of graphite atoms relies on the machining speed and substrate temperature improvement caused by the friction force. Besides, machining in a machined surface for multi-time is affected by its rough, amorphous, and deformed surface. Therefore, machining in the vertical direction for multi-time leads to a higher rate of deformation but a reduction in the rate of graphite atoms generation. Increasing the grain size could produce a larger graphite cluster, a higher elastic recovery rate, and a higher temperature but a lower force and pile-up height. Because the existence of the grain boundaries hinders the force transformation process, and the reduction in the grain size can soften the diamond substrate material.

Self-growing Hydrogel Particles with Applications for Reservoir Control: Growth Behaviors and Influencing Factors.

Chemical profile control agents are the key for conducting effective reservoir control to enhance crude oil recovery. Self-growing hydrogel particles have emerged as highly competitive profile control agents as they can grow for control after migrating to deep fractures, exhibiting great potential in long-term adaptive reservoir control. In this work, self-growing hydrogel particles were prepared by mechanical shearing of self-repairing bulk gels constructed by catechol-functionalized partially hydrolyzed polyacrylamide p[AM-AANa-DOPA] and phenolic resin cross-linking agents. After aging for 15 days under the reservoir conditions, the median size of hydrogel particles increased from ∼3.5 to ∼18.0 μm, demonstrating apparent self-growing property and significantly enhanced resistant coefficient in waterflooding. Different factors affecting growth behaviors of hydrogel particles including cross-linking density, chemical re-cross-linking, hydrolysis degree, and molecular weight of the copolymer were studied. The results showed that the cross-linking density affected the strength and toughness of the bulk hydrogel, with appropriate polymer chain mobility facilitating the intermolecular interactions. Quantitative NMR results of the gelation process indicated that chemical re-cross-linking contributed little to the growth of hydrogel particles. Based on the rheological and nanomechanical results, bulk gels prepared by polymers with a lower hydrolysis degree and smaller molecular weight possessed a higher elastic modulus recovery rate, while the corresponding hydrogel particles exhibited stronger adhesion among each other. This work provides new insights into the growth behavior of hydrogel particles, which may help better understand and select a suitable hydrogel system and preparation technology and further promote efficient reservoir control.

Investigation on Preparation and Properties of Crack Sealants Based on CNTs/SBS Composite-Modified Asphalt.

Crack is the main distress of asphalt pavement. Sealant is one of the most commonly used crack repair materials, and its performance is the key to affect the service life of asphalt pavements. In order to find an efficient modifier and optimize the performances of crack sealants. In this paper, carbon nanotubes (CNTs) and styrene-butadiene-styrene (SBS) were used as modifiers to prepare CNTs/SBS composite-modified asphalt crack sealant. The properties of the sealant were tested to evaluate its suitability for crack repair, which included the viscosity, softening point, resilience recovery, cone penetration, flow value, penetration, aging resistance, and fatigue resistance. The results showed that the conventional properties of the sealants meet the requirements of the specification. In addition, after heating aging, the elastic recovery rate of the sealant containing more CNTs decreased only slightly. The sealant containing 1 wt% CNTs exhibited a higher viscosity, fatigue resistance, thermal aging resistance.

P‐4.1: Research on RGB stacking instead of PS

At present, the cell structure of common liquid crystal displays generally adopts photolithography process to form post spacers (PS) on the glass substrate in order to maintain the cell gap (CG). The PS formed by this method would have uniform distribution, fixed position and high accuracy. However, the current PS not only requires a separate process, but also a single half‐tone mask in order to form two types of PS heights. The process mentioned above not only increases the manufacturing cost but also reduces the factory capacity. Aiming at the shortcomings of the current PS process, this article shows a design scheme that uses red, green and blue resistance stacks to form PS, referred to as resin PS. [1] This solution completely eliminates the PS process, saves costs, and increases factory production capacity. This paper systematically studied 12 stacking schemes and their effects on the height and size of Resin PS, and realized the step difference control of two resin PS. [2] The verification result found that the color resistance base station increases from bottom to top. The profile structure is relatively stable, as shown in Figure 1. The main PS would adopt a BGR triple stacked structure. The layer of each resin would be thicker, the final size and height would be larger. The sub PS is recommended to use B+G or B+ R dual stacking design, the step difference with the main PS is between 0.6–0.9um, which can be adjusted by the thickness of the hot melt flattening resin (OC); PS Size and height uniformity are good; the elastic recovery rate is 77%, which is closed to Normal PS. In short, the resin PS solution proposed in this paper has outstanding performance in parameters such as high uniformity, size uniformity, M‐S step control, profile, and elasticity, and has great potential to replace normal PS.