Encapsulation and controlled release of active agents is a common practice to improve processing and properties of materials and final products in different industries. Today, a large variety of chemical admixtures ar...Encapsulation and controlled release of active agents is a common practice to improve processing and properties of materials and final products in different industries. Today, a large variety of chemical admixtures are used in construction materials, the performance of which could be improved by a better dosage control. This work presents investigations on the controlled release of encapsulated construction chemicals for future applications in construction materials. The high shear mixing technology was used to produce matrix based encapsulations by agglomeration applied to commercially available construction materials. The agglomeration process was varied by the use of different agitator types, the variation of the agitator speed and the application of additional coating materials. The particle size distribution as well as the particle shape of the produced agglomerates was analyzed by automatic image evolution and scanning electron microscopy. The release behavior of the capsules in aqueous solutions was investigated by UV spectroscopy. The obtained results confirmed a theoretical model for the encapsulation and release of admixtures, which was derived from pharmaceutical drug release concepts and adapted to construction materials. The results indicate that the matrix based encapsulation is a promising technique for future applications in the field of construction materials.展开更多
A theoretical model extended from the Frenkel-Eyring molecular kinetic theory(MKT)was applied to describe the boundary slip on textured surfaces.The concept of the equivalent depth of potential well was adopted to cha...A theoretical model extended from the Frenkel-Eyring molecular kinetic theory(MKT)was applied to describe the boundary slip on textured surfaces.The concept of the equivalent depth of potential well was adopted to characterize the solid-liquid interactions on the textured surfaces.The slip behaviors on both chemically and topographically textured surfaces were investigated using molecular dynamics(MD)simulations.The extended MKT slip model is validated by our MD simulations under various situations,by constructing different complex surfaces and varying the surface wettability as well as the shear stress exerted on the liquid.This slip model can provide more comprehensive understanding of the liquid flow on atomic scale by considering the influence of the solid-liquid interactions and the applied shear stress on the nano-flow.Moreover,the slip velocity shear-rate dependence can be predicted using this slip model,since the nonlinear increase of the slip velocity under high shear stress can be approximated by a hyperbolic sine function.展开更多
文摘Encapsulation and controlled release of active agents is a common practice to improve processing and properties of materials and final products in different industries. Today, a large variety of chemical admixtures are used in construction materials, the performance of which could be improved by a better dosage control. This work presents investigations on the controlled release of encapsulated construction chemicals for future applications in construction materials. The high shear mixing technology was used to produce matrix based encapsulations by agglomeration applied to commercially available construction materials. The agglomeration process was varied by the use of different agitator types, the variation of the agitator speed and the application of additional coating materials. The particle size distribution as well as the particle shape of the produced agglomerates was analyzed by automatic image evolution and scanning electron microscopy. The release behavior of the capsules in aqueous solutions was investigated by UV spectroscopy. The obtained results confirmed a theoretical model for the encapsulation and release of admixtures, which was derived from pharmaceutical drug release concepts and adapted to construction materials. The results indicate that the matrix based encapsulation is a promising technique for future applications in the field of construction materials.
基金supported by the National Natural Science Foundation of China(Grant Nos.U1262103,11302218 and 11172289)Anhui Provincial Natural Science Foundation(Grant Nos.1308085QA10 and 1408085J08)the Fundamental Research Funds for the Central Universities of China
文摘A theoretical model extended from the Frenkel-Eyring molecular kinetic theory(MKT)was applied to describe the boundary slip on textured surfaces.The concept of the equivalent depth of potential well was adopted to characterize the solid-liquid interactions on the textured surfaces.The slip behaviors on both chemically and topographically textured surfaces were investigated using molecular dynamics(MD)simulations.The extended MKT slip model is validated by our MD simulations under various situations,by constructing different complex surfaces and varying the surface wettability as well as the shear stress exerted on the liquid.This slip model can provide more comprehensive understanding of the liquid flow on atomic scale by considering the influence of the solid-liquid interactions and the applied shear stress on the nano-flow.Moreover,the slip velocity shear-rate dependence can be predicted using this slip model,since the nonlinear increase of the slip velocity under high shear stress can be approximated by a hyperbolic sine function.
