Power cables are important pieces of equipment for energy transmission,but achieving a good balance between flame retardancy and mechanical properties of cable sheaths remains a challenge.In this work,a novel intumesc...Power cables are important pieces of equipment for energy transmission,but achieving a good balance between flame retardancy and mechanical properties of cable sheaths remains a challenge.In this work,a novel intumescent flame retardant(IFR)system containing silicone-containing macromolecular charring agent(Si-MCA)and ammonium polyphosphate(APP)was designed to synergistically improve the flame retardancy and mechanical properties of ethylene-butyl acrylate copolymer(EBA)composites.The optimal mass ratio of APP/Si-MCA was 3/1 in EBA composites(EBA/APP-Si-31),corresponding to the best flame retardancy with 31.2% of limited oxygen index(LOI),V-0 rating in UL-94 vertical burning test,and 76.4%reduction on the peak of heat release rate(PHRR)in cone calorimeter test.The enhancement mechanism was attributed to the synergistic effect of APP/Si-MCA during combustion,including the radical-trapping effect,the dilution effect of non-flammable gases,and the barrier effect of the intumescent char layer.Meanwhile,the tensile results indicated that EBA/APP-Si-31 also exhibited good mechanical properties with the addition of maleic anhydride-grafted polyethylene(PE-g-MA)as the compatibilizer.Thus,the APP/Si-MCA combination is an effective IFRs system for preparing high-performance EBA composites,and it will promote their applications as cable sheath materials.展开更多
Targeted delivery of neurochemicals and biomolecules for neuromodulation of brain activity is a powerful technique that,in addition to electrical recording and stimulation,enables a more thorough investigation of neur...Targeted delivery of neurochemicals and biomolecules for neuromodulation of brain activity is a powerful technique that,in addition to electrical recording and stimulation,enables a more thorough investigation of neural circuit dynamics.We have designed a novel,flexible,implantable neural probe capable of controlled,localized chemical stimulation and electrophysiology recording.The neural probe was implemented using planar micromachining processes on Parylene C,a mechanically flexible,biocompatible substrate.The probe shank features two large microelectrodes(chemical sites)for drug loading and sixteen small microelectrodes for electrophysiology recording to monitor neuronal response to drug release.To reduce the impedance while keeping the size of the microelectrodes small,poly(3,4-ethylenedioxythiophene)(PEDOT)was electrochemically coated on recording microelectrodes.In addition,PEDOT doped with mesoporous sulfonated silica nanoparticles(SNPs)was used on chemical sites to achieve controlled,electrically-actuated drug loading and releasing.Different neurotransmitters,including glutamate(Glu)and gamma-aminobutyric acid(GABA),were incorporated into the SNPs and electrically triggered to release repeatedly.An in vitro experiment was conducted to quantify the stimulated release profile by applying a sinusoidal voltage(0.5 V,2 Hz).The flexible neural probe was implanted in the barrel cortex of the wild-type Sprague Dawley rats.As expected,due to their excitatory and inhibitory effects,Glu and GABA release caused a significant increase and decrease in neural activity,respectively,which was recorded by the recording microelectrodes.This novel flexible neural probe technology,combining on-demand chemical release and high-resolution electrophysiology recording,is an important addition to the neuroscience toolset used to dissect neural circuitry and investigate neural network connectivity.展开更多
基金supported by the National Natural Science Foundation of China(52473059)Taishan Scholar Constructive Engineering Foundation of Shandong Province(tsqn202103079)Key Research and Development Plan of Shandong Province(2024TSGC0264).
文摘Power cables are important pieces of equipment for energy transmission,but achieving a good balance between flame retardancy and mechanical properties of cable sheaths remains a challenge.In this work,a novel intumescent flame retardant(IFR)system containing silicone-containing macromolecular charring agent(Si-MCA)and ammonium polyphosphate(APP)was designed to synergistically improve the flame retardancy and mechanical properties of ethylene-butyl acrylate copolymer(EBA)composites.The optimal mass ratio of APP/Si-MCA was 3/1 in EBA composites(EBA/APP-Si-31),corresponding to the best flame retardancy with 31.2% of limited oxygen index(LOI),V-0 rating in UL-94 vertical burning test,and 76.4%reduction on the peak of heat release rate(PHRR)in cone calorimeter test.The enhancement mechanism was attributed to the synergistic effect of APP/Si-MCA during combustion,including the radical-trapping effect,the dilution effect of non-flammable gases,and the barrier effect of the intumescent char layer.Meanwhile,the tensile results indicated that EBA/APP-Si-31 also exhibited good mechanical properties with the addition of maleic anhydride-grafted polyethylene(PE-g-MA)as the compatibilizer.Thus,the APP/Si-MCA combination is an effective IFRs system for preparing high-performance EBA composites,and it will promote their applications as cable sheath materials.
基金supported in part by the National Science Foundation,Integrative Strategies for Understanding Neural and Cognitive Systems(NSF-NCS)under Grant Nos.1926804 and 1926756in part by the National Institute of Neurological Disorders and Stroke of the National Institutes of Health under Award Number R01NS110564 and 1RF1NS113303support of the Carnegie Mellon Nanotechnology facility.
文摘Targeted delivery of neurochemicals and biomolecules for neuromodulation of brain activity is a powerful technique that,in addition to electrical recording and stimulation,enables a more thorough investigation of neural circuit dynamics.We have designed a novel,flexible,implantable neural probe capable of controlled,localized chemical stimulation and electrophysiology recording.The neural probe was implemented using planar micromachining processes on Parylene C,a mechanically flexible,biocompatible substrate.The probe shank features two large microelectrodes(chemical sites)for drug loading and sixteen small microelectrodes for electrophysiology recording to monitor neuronal response to drug release.To reduce the impedance while keeping the size of the microelectrodes small,poly(3,4-ethylenedioxythiophene)(PEDOT)was electrochemically coated on recording microelectrodes.In addition,PEDOT doped with mesoporous sulfonated silica nanoparticles(SNPs)was used on chemical sites to achieve controlled,electrically-actuated drug loading and releasing.Different neurotransmitters,including glutamate(Glu)and gamma-aminobutyric acid(GABA),were incorporated into the SNPs and electrically triggered to release repeatedly.An in vitro experiment was conducted to quantify the stimulated release profile by applying a sinusoidal voltage(0.5 V,2 Hz).The flexible neural probe was implanted in the barrel cortex of the wild-type Sprague Dawley rats.As expected,due to their excitatory and inhibitory effects,Glu and GABA release caused a significant increase and decrease in neural activity,respectively,which was recorded by the recording microelectrodes.This novel flexible neural probe technology,combining on-demand chemical release and high-resolution electrophysiology recording,is an important addition to the neuroscience toolset used to dissect neural circuitry and investigate neural network connectivity.
