Notably, these cured MCBP films demonstrated excellent antibacterial and algaecidal properties due to the presence of daidzein and furan units. This work first presents the new application prospect of bio-based MCBPs, for example, in marine antifouling coatings. Copyright © 2020 American Chemical Society.Compared to the shale gas and coalbed methane in China, tight gas has been recently considered as a priority in the exploration and exploitation of unconventional gas resources. In the development of a tight gas field, how to enhance the gas recovery is a prevalent topic. Unlike the conventional gas reservoir, the ultimate gas recovery is not only determined by the geological characteristics but is also affected by other factors such as well drainage area and well spacing design. For tight sandstone reservoirs, the gas recovery can be improved by increasing the drainage area. Moreover, the well drainage area is closely associated with well spacing. Therefore, effective drainage area estimation and well spacing optimization are essential aspects for tight gas exploitation. In this paper, a new optimization workflow is established, which combined dynamic analysis and numerical simulation techniques. First, through interference well test results and production data dynamic analysis, the total gas production can be expressed and predicted. Then the well density can be optimized by the economic evaluation method. Meanwhile, a numerical model is built up to determine the optimal well spacing. This new optimization workflow can provide guidance to the operators of tight gas fields where the interference well test results are available and several years of production data are collected. https://www.selleckchem.com/products/chitosan-oligosaccharide.html Furthermore, in the case of the Sulige gas field, the single well drainage area is estimated and the optimal well pattern is obtained by the established approach. The results indicate that the well pattern of 500 m × 600 m is most reasonable for the pilot gas field. Copyright © 2020 American Chemical Society.A three-dimensional-two-dimensional dimensionality transition of organic microcrystals was performed via elongated octahedrons, oblique octahedrons, diamond-like particles, and parallelograms using nonplanar 2,7-di(9H-carbazol-9-yl)spiro[fluorene-9,9'-xanthene] molecules. The specific crystal symmetry and selective adhesion of P123 on the 11-1s facet are supposed to induce the morphological transition. Copyright © 2020 American Chemical Society.The standardization of secondary electrolytic conductivity cells requires the use of a certified reference material. The accepted certification method involves electrochemical impedance spectroscopy (EIS) to estimate the material's solution resistance. This method normally assumes that the impedance's imaginary component can be neglected; and hence, the measured impedance approximates the real impedance. Thus, a linear extrapolation of the impedance versus the period (inverse frequency) yields solution resistance. However, experimental impedance data usually do not exhibit a linear behavior over the spectra of frequency, which strongly suggest that the ideal capacitive assumption may not strictly apply. To account for the observed nonlinear behavior, we have proposed to introduce the concept of a constant phase element (CPE) to the analysis of impedance. This approach leads to the development of a relationship that improves the fitting of experimental data and improves the accuracy of the estimation, by establishing a critical frequency where extrapolation should be done. Finally, we are presenting simulated results to demonstrate how sizeable capacitive effects can influence the determination of solution resistance, and a final analysis to estimate the impact on constant cell or electrolytic conductivity values. Copyright © 2020 American Chemical Society.We report a thermoresponsive double hydrophilic block copolymer degradable in response to dual reduction and acidic pH at dual locations. The copolymer consists of a poly(ethylene oxide) block covalently connected through an acid-labile acetal linkage with a thermoresponsive polymethacrylate block containing pendant oligo(ethylene oxide) and disulfide groups. The copolymer undergoes temperature-driven self-assembly in water to form nanoassemblies with acetal linkages at the core/corona interface and disulfide pendants in the core, exhibiting dual reduction/acid responses at dual locations. The physically assembled nanoaggregates are converted to disulfide-core-crosslinked nanogels through disulfide-thiol exchange reaction, retaining enhanced colloidal stability, yet degraded to water-soluble unimers upon reduction/acid-responsive degradation. Further, the copolymer exhibits improved tunability of thermoresponsive property upon the cleavage of junction acetal and pendant disulfide linkages individually and in combined manner. This work suggests that dual location dual reduction/acid-responsive degradation is a versatile strategy toward effective drug delivery exhibiting disulfide-core-crosslinking capability and disassembly as well as improved thermoresponsive tunability. Copyright © 2020 American Chemical Society.Poly(ethylene imine) (PEI) has abundant amino groups in a macromolecular chain and can be used as a graft source for metal nanocomposites, which shows excellent ability to form stable complexes with heavy metal ions. In this work, a simple and convenient method was used to make PEI into a stable hydrogel with 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide-N-hydroxysuccinimide and subsequently coprecipitate with silver nitrate solution or palladium chloride solution to form metal-loaded composite hydrogels. In addition, the characterizations of composite hydrogels were investigated by scanning electron microscopy, specific surface area tests (Brunauer-Emmett-Teller), X-ray photoelectron spectroscopy, and ultraviolet spectroscopy. The properties of composite hydrogels on the catalytic reduction of 4-nitrophenol were studied. The results showed that the composite hydrogels could be easily separated from the water environment, which indicated the large-scale potential application in organic catalytic degradation and wastewater treatment.
Notably, these cured MCBP films demonstrated excellent antibacterial and algaecidal properties due to the presence of daidzein and furan units. This work first presents the new application prospect of bio-based MCBPs, for example, in marine antifouling coatings. Copyright © 2020 American Chemical Society.Compared to the shale gas and coalbed methane in China, tight gas has been recently considered as a priority in the exploration and exploitation of unconventional gas resources. In the development of a tight gas field, how to enhance the gas recovery is a prevalent topic. Unlike the conventional gas reservoir, the ultimate gas recovery is not only determined by the geological characteristics but is also affected by other factors such as well drainage area and well spacing design. For tight sandstone reservoirs, the gas recovery can be improved by increasing the drainage area. Moreover, the well drainage area is closely associated with well spacing. Therefore, effective drainage area estimation and well spacing optimization are essential aspects for tight gas exploitation. In this paper, a new optimization workflow is established, which combined dynamic analysis and numerical simulation techniques. First, through interference well test results and production data dynamic analysis, the total gas production can be expressed and predicted. Then the well density can be optimized by the economic evaluation method. Meanwhile, a numerical model is built up to determine the optimal well spacing. This new optimization workflow can provide guidance to the operators of tight gas fields where the interference well test results are available and several years of production data are collected. https://www.selleckchem.com/products/chitosan-oligosaccharide.html Furthermore, in the case of the Sulige gas field, the single well drainage area is estimated and the optimal well pattern is obtained by the established approach. The results indicate that the well pattern of 500 m × 600 m is most reasonable for the pilot gas field. Copyright © 2020 American Chemical Society.A three-dimensional-two-dimensional dimensionality transition of organic microcrystals was performed via elongated octahedrons, oblique octahedrons, diamond-like particles, and parallelograms using nonplanar 2,7-di(9H-carbazol-9-yl)spiro[fluorene-9,9'-xanthene] molecules. The specific crystal symmetry and selective adhesion of P123 on the 11-1s facet are supposed to induce the morphological transition. Copyright © 2020 American Chemical Society.The standardization of secondary electrolytic conductivity cells requires the use of a certified reference material. The accepted certification method involves electrochemical impedance spectroscopy (EIS) to estimate the material's solution resistance. This method normally assumes that the impedance's imaginary component can be neglected; and hence, the measured impedance approximates the real impedance. Thus, a linear extrapolation of the impedance versus the period (inverse frequency) yields solution resistance. However, experimental impedance data usually do not exhibit a linear behavior over the spectra of frequency, which strongly suggest that the ideal capacitive assumption may not strictly apply. To account for the observed nonlinear behavior, we have proposed to introduce the concept of a constant phase element (CPE) to the analysis of impedance. This approach leads to the development of a relationship that improves the fitting of experimental data and improves the accuracy of the estimation, by establishing a critical frequency where extrapolation should be done. Finally, we are presenting simulated results to demonstrate how sizeable capacitive effects can influence the determination of solution resistance, and a final analysis to estimate the impact on constant cell or electrolytic conductivity values. Copyright © 2020 American Chemical Society.We report a thermoresponsive double hydrophilic block copolymer degradable in response to dual reduction and acidic pH at dual locations. The copolymer consists of a poly(ethylene oxide) block covalently connected through an acid-labile acetal linkage with a thermoresponsive polymethacrylate block containing pendant oligo(ethylene oxide) and disulfide groups. The copolymer undergoes temperature-driven self-assembly in water to form nanoassemblies with acetal linkages at the core/corona interface and disulfide pendants in the core, exhibiting dual reduction/acid responses at dual locations. The physically assembled nanoaggregates are converted to disulfide-core-crosslinked nanogels through disulfide-thiol exchange reaction, retaining enhanced colloidal stability, yet degraded to water-soluble unimers upon reduction/acid-responsive degradation. Further, the copolymer exhibits improved tunability of thermoresponsive property upon the cleavage of junction acetal and pendant disulfide linkages individually and in combined manner. This work suggests that dual location dual reduction/acid-responsive degradation is a versatile strategy toward effective drug delivery exhibiting disulfide-core-crosslinking capability and disassembly as well as improved thermoresponsive tunability. Copyright © 2020 American Chemical Society.Poly(ethylene imine) (PEI) has abundant amino groups in a macromolecular chain and can be used as a graft source for metal nanocomposites, which shows excellent ability to form stable complexes with heavy metal ions. In this work, a simple and convenient method was used to make PEI into a stable hydrogel with 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide-N-hydroxysuccinimide and subsequently coprecipitate with silver nitrate solution or palladium chloride solution to form metal-loaded composite hydrogels. In addition, the characterizations of composite hydrogels were investigated by scanning electron microscopy, specific surface area tests (Brunauer-Emmett-Teller), X-ray photoelectron spectroscopy, and ultraviolet spectroscopy. The properties of composite hydrogels on the catalytic reduction of 4-nitrophenol were studied. The results showed that the composite hydrogels could be easily separated from the water environment, which indicated the large-scale potential application in organic catalytic degradation and wastewater treatment.
0 Comments
0 Shares
25 Views
0 Reviews
