By using redispersible polymer powder（RPP） and carbon fiber（CF） to adjust the flexibility and electrical properties of the smart aggregate, a new kind of smart aggregate with Z type structure was proposed. The stu...By using redispersible polymer powder（RPP） and carbon fiber（CF） to adjust the flexibility and electrical properties of the smart aggregate, a new kind of smart aggregate with Z type structure was proposed. The study shows that Z type aggregate is more sensitive to the feedback of external force than the prism aggregate in the same loading environment, and it indicates that Z type aggregate is more suitable for the research and application of concrete health monitoring. Although the incorporation of RPP would cause the compressive strength of the aggregates and the elastic modulus of hardened cement mortar to reduce slightly within the dosage of RPP by 2.25% because of the polymer film formed in the internal system, this would improve the deformability of the aggregates. In the early loading stage（in the first 60 seconds）, the intelligent concrete specimens implanted with Z type smart aggregate do not show higher sensitivity as expected, although the resistance change rate changes a little bit more, the overall of it is still in balance. Adding RPP could improve the flexibility of smart aggregates exactly, and it plays an active role in prolonging the life of the smart aggregates. By implanting Z type aggregates the damage and failure of the concrete structure could be predicted accurately in this study. The results of this paper will help to promote further research and application of intelligent concrete.展开更多
It was determined that samples of styrene-butadiene rubber(SBR),containing highly aromatic oil,exhibit memory effects giving rise to dynamic elastic modulus,damping and internal stresses degree which can be tailored d...It was determined that samples of styrene-butadiene rubber(SBR),containing highly aromatic oil,exhibit memory effects giving rise to dynamic elastic modulus,damping and internal stresses degree which can be tailored depending on the applied electric field strength.The capability and stability of the interaction process between aligned neighbor dipoles for exhibiting a memory effect,once the aligning electric field was removed are studied.It is determined that depending on the spatial arrangement and the amount of electric charge of the dipoles,this interaction is able to promote a memory effect which keeps the alignment between them.This electrostatic interaction plays the role of a counteracting effect for keeping the alignment,which was called electroelasticity.The results from the developed model were applied successfully to SBR composite samples for explaining the memory effects recorded from dynamic mechanical analysis(DMA)measurements under electric field.In addition,the model of the electric inclusion based on the inclusion theory for continuous media,was applied to determine the degree of internal stresses in the dielectric composite material due to the external applied electric field.In addition,from the coupling between the model developed here and simple issues related to the mechanical properties of composite materials,a procedure for determining the maximum possible gap between the electric dipoles in composite dielectric materials is also shown.展开更多
A new electroactive polymer 1 with alternating NDI （naphthalene diimide） moieties and fluorinated alkyl chains was prepared and characterized. Gels of polymer 1 were formed in several solvents. Interestingly, gels o...A new electroactive polymer 1 with alternating NDI （naphthalene diimide） moieties and fluorinated alkyl chains was prepared and characterized. Gels of polymer 1 were formed in several solvents. Interestingly, gels of polymer 1 exhibited responsiveness toward N2H4, F and CN . Absorption and ESR spectroscopic studies revealed that such responsiveness is owing to the reduction of NDI moieties into the respective NDI＇-. In addition, thin films of polymer 1 were easily prepared with spin-coating technique and the electrical conductivity of thin films reached 52.4 S/m after exposure to NeH4 vapor.展开更多
基金Funded by the Natural Science Foundation of Fujian Province(No.2016J01241)the National Natural Science Foundation of China(No.51608212)the Science&Technology Pillar Program of Fujian Provincial Education Department(No.JA14024)
文摘By using redispersible polymer powder（RPP） and carbon fiber（CF） to adjust the flexibility and electrical properties of the smart aggregate, a new kind of smart aggregate with Z type structure was proposed. The study shows that Z type aggregate is more sensitive to the feedback of external force than the prism aggregate in the same loading environment, and it indicates that Z type aggregate is more suitable for the research and application of concrete health monitoring. Although the incorporation of RPP would cause the compressive strength of the aggregates and the elastic modulus of hardened cement mortar to reduce slightly within the dosage of RPP by 2.25% because of the polymer film formed in the internal system, this would improve the deformability of the aggregates. In the early loading stage（in the first 60 seconds）, the intelligent concrete specimens implanted with Z type smart aggregate do not show higher sensitivity as expected, although the resistance change rate changes a little bit more, the overall of it is still in balance. Adding RPP could improve the flexibility of smart aggregates exactly, and it plays an active role in prolonging the life of the smart aggregates. By implanting Z type aggregates the damage and failure of the concrete structure could be predicted accurately in this study. The results of this paper will help to promote further research and application of intelligent concrete.
文摘It was determined that samples of styrene-butadiene rubber(SBR),containing highly aromatic oil,exhibit memory effects giving rise to dynamic elastic modulus,damping and internal stresses degree which can be tailored depending on the applied electric field strength.The capability and stability of the interaction process between aligned neighbor dipoles for exhibiting a memory effect,once the aligning electric field was removed are studied.It is determined that depending on the spatial arrangement and the amount of electric charge of the dipoles,this interaction is able to promote a memory effect which keeps the alignment between them.This electrostatic interaction plays the role of a counteracting effect for keeping the alignment,which was called electroelasticity.The results from the developed model were applied successfully to SBR composite samples for explaining the memory effects recorded from dynamic mechanical analysis(DMA)measurements under electric field.In addition,the model of the electric inclusion based on the inclusion theory for continuous media,was applied to determine the degree of internal stresses in the dielectric composite material due to the external applied electric field.In addition,from the coupling between the model developed here and simple issues related to the mechanical properties of composite materials,a procedure for determining the maximum possible gap between the electric dipoles in composite dielectric materials is also shown.
基金Supporting information for this article is available on the WWW under bttp：//dx.doi.org/10. 1002/cjoc.201200029 or from the author.AcknowledgementThe present research was financially supported by the National Natural Science Foundation of China （Nos. 50973120, 21021091, 20902092）, Chinese Academy of Science, and State Key Basic Research Program.
文摘A new electroactive polymer 1 with alternating NDI （naphthalene diimide） moieties and fluorinated alkyl chains was prepared and characterized. Gels of polymer 1 were formed in several solvents. Interestingly, gels of polymer 1 exhibited responsiveness toward N2H4, F and CN . Absorption and ESR spectroscopic studies revealed that such responsiveness is owing to the reduction of NDI moieties into the respective NDI＇-. In addition, thin films of polymer 1 were easily prepared with spin-coating technique and the electrical conductivity of thin films reached 52.4 S/m after exposure to NeH4 vapor.
