It is still challenging for conductive polymer composite-based electromagnetic interference(EMI)shielding materials to achieve long-term stability while maintaining high EMI shielding effectiveness(EMI SE),especially ...It is still challenging for conductive polymer composite-based electromagnetic interference(EMI)shielding materials to achieve long-term stability while maintaining high EMI shielding effectiveness(EMI SE),especially undergoing external mechanical stimuli,such as scratches or large deformations.Herein,an electrostatic assembly strategy is adopted to design a healable and segregated carbon nanotube(CNT)/graphene oxide(GO)/polyurethane(PU)composite with excellent and reliable EMI SE,even bearing complex mechanical condition.The negatively charged CNT/GO hybrid is facilely adsorbed on the surface of positively charged PU microsphere to motivate formation of segregated conductive networks in CNT/GO/PU composite,establishing a high EMI SE of 52.7 dB at only 10 wt%CNT/GO loading.The Diels–Alder bonds in PU microsphere endow the CNT/GO/PU composite suffering three cutting/healing cycles with EMI SE retention up to 90%.Additionally,the electrostatic attraction between CNT/GO hybrid and PU microsphere helps to strong interfacial bonding in the composite,resulting in high tensile strength of 43.1 MPa and elongation at break of 626%.The healing efficiency of elongation at break achieves 95%when the composite endured three cutting/healing cycles.This work demonstrates a novel strategy for developing segregated EMI shielding composite with healable features and excellent mechanical performance and shows great potential in the durable and high precision electrical instruments.展开更多
The phenomenon of electrical attraction and repulsion between charged particles is well known, and described mathematically by Coulomb’s Law, yet until now there has been no explanation for why this occurs. There has...The phenomenon of electrical attraction and repulsion between charged particles is well known, and described mathematically by Coulomb’s Law, yet until now there has been no explanation for why this occurs. There has been no mechanistic explanation that reveals what causes the charged particles to accelerate, either towards or away from each other. This paper gives a detailed explanation of the phenomena of electrical attraction and repulsion based on my previous work that determined the exact wave-function solutions for both the Electron and the Positron. It is revealed that the effects are caused by wave interactions between the wave functions that result in Electromagnetic reflections of parts of the particle’s wave functions, causing a change in their momenta.展开更多
Crylic acid and azobenzene containing acrylate copolymers PEAPH were fabricated into multilayers with their counterpart polyelectrolyte(poly(diallyldimethylammonium) chloride)(PDAC) in N,N′-dimethylformamide(DMF) usi...Crylic acid and azobenzene containing acrylate copolymers PEAPH were fabricated into multilayers with their counterpart polyelectrolyte(poly(diallyldimethylammonium) chloride)(PDAC) in N,N′-dimethylformamide(DMF) using the layer-by-layer electrostatic adsorption technique.The self-assembly of water soluble and insoluble PEAPH in DMF was studied and compared.FTIR was used to detect the ionization of carboxyl acid of PEAPH during the assembling processes.All results show that both the water-soluble and water-insoluble PEAPH can be deposited with PDAC based on the electrostatic attraction instead of other interactions.In assembling processes PEAPH molecules are deposited in molecular level instead of molecular aggregation and form a cross-linking multilayer structure.Assembling media of DMF and water do not have obvious influence on the multilayer structure.展开更多
Nanoenzyme-mediated antibacterial strategies have been widely exploited to overcome the shortcomings(such as drug resistance and mild-to-severe side effects) of antibiotic therapy.The peroxidase-like activity of nanoe...Nanoenzyme-mediated antibacterial strategies have been widely exploited to overcome the shortcomings(such as drug resistance and mild-to-severe side effects) of antibiotic therapy.The peroxidase-like activity of nanoenzymes possesses great potential against bacterial infection by the generation of hydroxyl radical(·OH) in the specific microenvironment.However,the lifetime of-OH is extremely short,and a large amount of the ·OH generated within the infection microenvironment cannot come into contact with bacteria quickly enough,thus resulting in low treatment efficiency.Here,chitosan-oligosaccharide-modified CuS nanoparticles possessing positive charges(PCuS NPs) were prepared using a one-pot method.PCuS NPs exhibited efficient peroxidase-like activity.Importantly,the PCuS NPs can combine with bacteria via electrostatic attraction.The direct contact between the PCuS NPs and bacteria enabled the generation of ·OH in situ on the bacterial surface,ultimately leading to a high antibacterial efficacy at a low concentration in the presence of H_(2)O_(2).At an effective antibacterial concentration,the PCuS NPs exhibited high cytocompatibility.Furthermore,in vivo results revealed that PCuS NPs not only decreased the size of abscesses but also reduced inflammation and promoted collagen fiber formation.Therefore,PCuS NPs possess great potential against bacterial infection via in situ ·OH generation based on electrostatic attraction.展开更多
基金The authors gratefully acknowledge the financial support from the National Natural Science Foundation of China(Grant Nos.51973142,51721091,21878194)the National Key Research and Development Program of China(2018YFB0704200)the funds of the State Key Laboratory of Solidification Processing(Northwestern Polytechnical University)(SKLSP201918).
文摘It is still challenging for conductive polymer composite-based electromagnetic interference(EMI)shielding materials to achieve long-term stability while maintaining high EMI shielding effectiveness(EMI SE),especially undergoing external mechanical stimuli,such as scratches or large deformations.Herein,an electrostatic assembly strategy is adopted to design a healable and segregated carbon nanotube(CNT)/graphene oxide(GO)/polyurethane(PU)composite with excellent and reliable EMI SE,even bearing complex mechanical condition.The negatively charged CNT/GO hybrid is facilely adsorbed on the surface of positively charged PU microsphere to motivate formation of segregated conductive networks in CNT/GO/PU composite,establishing a high EMI SE of 52.7 dB at only 10 wt%CNT/GO loading.The Diels–Alder bonds in PU microsphere endow the CNT/GO/PU composite suffering three cutting/healing cycles with EMI SE retention up to 90%.Additionally,the electrostatic attraction between CNT/GO hybrid and PU microsphere helps to strong interfacial bonding in the composite,resulting in high tensile strength of 43.1 MPa and elongation at break of 626%.The healing efficiency of elongation at break achieves 95%when the composite endured three cutting/healing cycles.This work demonstrates a novel strategy for developing segregated EMI shielding composite with healable features and excellent mechanical performance and shows great potential in the durable and high precision electrical instruments.
文摘The phenomenon of electrical attraction and repulsion between charged particles is well known, and described mathematically by Coulomb’s Law, yet until now there has been no explanation for why this occurs. There has been no mechanistic explanation that reveals what causes the charged particles to accelerate, either towards or away from each other. This paper gives a detailed explanation of the phenomena of electrical attraction and repulsion based on my previous work that determined the exact wave-function solutions for both the Electron and the Positron. It is revealed that the effects are caused by wave interactions between the wave functions that result in Electromagnetic reflections of parts of the particle’s wave functions, causing a change in their momenta.
基金the National Natural Science Foundation of China(No.52074138)the Fundamental Research Project of Yunnan Province,China(No.202001AS070030)the Analysis and Testing Foundation of Kunming University of Science and Technology,China(No.2018M20162101102).
文摘Crylic acid and azobenzene containing acrylate copolymers PEAPH were fabricated into multilayers with their counterpart polyelectrolyte(poly(diallyldimethylammonium) chloride)(PDAC) in N,N′-dimethylformamide(DMF) using the layer-by-layer electrostatic adsorption technique.The self-assembly of water soluble and insoluble PEAPH in DMF was studied and compared.FTIR was used to detect the ionization of carboxyl acid of PEAPH during the assembling processes.All results show that both the water-soluble and water-insoluble PEAPH can be deposited with PDAC based on the electrostatic attraction instead of other interactions.In assembling processes PEAPH molecules are deposited in molecular level instead of molecular aggregation and form a cross-linking multilayer structure.Assembling media of DMF and water do not have obvious influence on the multilayer structure.
基金financially supported by the National Natural Science Foundation of China (No.82100974)the Natural Science Foundation of Shandong Province (No.ZR2021QH241)Qilu Young Scholars Program of Shandong University。
文摘Nanoenzyme-mediated antibacterial strategies have been widely exploited to overcome the shortcomings(such as drug resistance and mild-to-severe side effects) of antibiotic therapy.The peroxidase-like activity of nanoenzymes possesses great potential against bacterial infection by the generation of hydroxyl radical(·OH) in the specific microenvironment.However,the lifetime of-OH is extremely short,and a large amount of the ·OH generated within the infection microenvironment cannot come into contact with bacteria quickly enough,thus resulting in low treatment efficiency.Here,chitosan-oligosaccharide-modified CuS nanoparticles possessing positive charges(PCuS NPs) were prepared using a one-pot method.PCuS NPs exhibited efficient peroxidase-like activity.Importantly,the PCuS NPs can combine with bacteria via electrostatic attraction.The direct contact between the PCuS NPs and bacteria enabled the generation of ·OH in situ on the bacterial surface,ultimately leading to a high antibacterial efficacy at a low concentration in the presence of H_(2)O_(2).At an effective antibacterial concentration,the PCuS NPs exhibited high cytocompatibility.Furthermore,in vivo results revealed that PCuS NPs not only decreased the size of abscesses but also reduced inflammation and promoted collagen fiber formation.Therefore,PCuS NPs possess great potential against bacterial infection via in situ ·OH generation based on electrostatic attraction.
