Fire Intumescent,High-Temperature Resistant,Mechanically Flexible Graphene Oxide Network for Exceptional Fire Shielding and Ultra-Fast Fire Warning

Smart fire alarm sensor(FAS)materials with mechanically robust,excellent flame retardancy as well as ultra-sensitive temperature-responsive capability are highly attractive platforms for fire safety application.However,most reported FAS materials can hardly provide sensitive,continuous and reliable alarm signal output due to their undesirable temperature-responsive,flame-resistant and mechanical performances.To overcome these hurdles,herein,we utilize the multi-amino molecule,named HCPA,that can serve as triple-roles including cross-linker,fire retardant and reducing agent for decorating graphene oxide(GO)sheets and obtaining the GO/HCPA hybrid networks.Benefiting from the formation of multi-interactions in hybrid network,the optimized GO/HCPA network exhibits significant increment in mechanical strength,e.g.,tensile strength and toughness increase of~2.3and~5.7 times,respectively,compared to the control one.More importantly,based on P and N doping and promoting thermal reduction effect on GO network,the excellent flame retardancy(withstanding~1200℃flame attack),ultra-fast fire alarm response time(~0.6 s)and ultra-long alarming period(>600 s)are obtained,representing the best comprehensive performance of GO-based FAS counterparts.Furthermore,based on GO/HCPA network,the fireproof coating is constructed and applied in polymer foam and exhibited exceptional fire shielding performance.This work provides a new idea for designing and fabricating desirable FAS materials and fireproof coatings.

Formation and distribution characteristics of Proterozoic–Lower Paleozoic marine giant oil and gas fields worldwide

There are rich oil and gas resources in marine carbonate strata worldwide.Although most of the oil and gas reserves discovered so far are mainly distributed in Mesozoic,Cenozoic,and upper Paleozoic strata,oil and gas exploration in the Proterozoic–Lower Paleozoic（PLP）strata—the oldest marine strata—has been very limited.To more clearly understand the oil and gas formation conditions and distributions in the PLP marine carbonate strata,we analyzed and characterized the petroleum geological conditions,oil and gas reservoir types,and their distributions in thirteen giant oil and gas fields worldwide.This study reveals the main factors controlling their formation and distribution.Our analyses show that the source rocks for these giant oil and gas fields are mainly shale with a great abundance of type I–II organic matter and a high thermal evolution extent.The reservoirs are mainly gas reservoirs,and the reservoir rocks are dominated by dolomite.The reservoir types are mainly karst and reef–shoal bodies with well-developed dissolved pores and cavities,intercrystalline pores,and fractures.These reservoirs arehighly heterogeneous.The burial depth of the reservoirs is highly variable and somewhat negatively correlated to the porosity.The cap rocks are mainly thick evaporites and shales,with the thickness of the cap rocks positively correlated to the oil and gas reserves.The development of high-quality evaporite cap rock is highly favorable for oil and gas preservation.We identified four hydrocarbon generation models,and that the major source rocks have undergone a long period of burial and thermal evolution and are characterized by early and long periods of hydrocarbon generation.These giant oil and gas fields have diverse types of reservoirs and are mainly distributed in paleo-uplifts,slope zones,and platform margin reef-shoal bodies.The main factors that control their formation and distribution were identified,enabling the prediction of new favorable areas for oil and gas exploration.