Tianjin, China

Tianjin Polytechnic University is a university in Tianjin, China under the municipal government. It is also referred to as TJPU. The university was founded in 1912 and currently has fourteen colleges on two campuses in the city. The old campus is located in the Hedong District , and the new one is in the Xiqing District . Wikipedia.


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Patent
Tianjin Polytechnic University | Date: 2017-05-03

A hollow tubular oil absorbing material includes: a core formed by a spring, and an outer shell formed by a flat sponge wrapped at the spring; wherein the flat sponge is fixed at both ends of the spring; the flat sponge fully covers all the spring or is sealed at a first end; a connecting tube is connected at a second end of the spring for communicating with a vacuum pump; a graphene oxide layer is coated at the outer sponge. The graphene oxide layer on the flat sponge of hollow tubular oil absorbing material is formed by immersion and coating under negative pressure. Further the reduction of graphene oxide is performed with hydrazine hydrate steam and followed by washing and drying. Finally, a hollow tubular sponge with a spring core and an outer grapheme-coated sponge structure is obtained. The present invention is a simple method for preparing hollow tubular oil absorbing material. The low-cost hollow tubular oil absorbing material is able to continuously work for oil absorption and separation, which can improve efficiency of oil-water separation.


This science illustration demonstrates the collapsing of the balloon-shaped-reaction product during the charging of the lithium-oxygen battery. Credit: Environmental Molecular Sciences Laboratory For the lithium-oxygen battery system, it is well recognized the charging and discharging reaction produces peculiar reaction product shapes that resemble doughnuts and balloons. Yet, how these shapes form has remained a mystery. A new study of a functioning nano-lithium-oxygen battery at atomic scale in an oxygen atmosphere provides clues for solving this mystery. The discovery of the lithium-oxygen reaction pathway sets the foundation for quantitative modeling of electrochemical processes in the lithium-oxygen system, providing insight into how best to design lithium-oxygen batteries with high capacity and longer cycle life. The lithium-oxygen battery system has been perceived as an enabling technology for the electromotive industry. However, progress in research and development of a lithium-oxygen battery has been severely hampered by two unanswered questions. First, what is the electrochemical reaction route when discharging and charging the battery? Second, what is the relationship between the complicated shapes of the reaction product and the reaction path? Answers to these two questions are fundamental, yet essential for development of the lithium-oxygen batteries. To address this knowledge gap, a team of researchers from Pacific Northwest National Laboratory; Tianjin Polytechnic University of China; and EMSL, the Environmental Molecular Sciences Laboratory, used advanced in-situ imaging techniques—the environmental transmission electron microscope—at EMSL, a Department of Energy Office of Science user facility, to observe a nano-lithium-oxygen battery during charging and discharging. They found oxygen reacts with lithium on carbon nanotubes to form a metastable lithium oxide. This oxide transforms into a more stable lithium oxide and releases oxygen gas that expands (inflates) particles into a hollow structure, producing doughnut and balloon shapes. This observation more generally demonstrates that the way the released oxygen is accommodated governs the formation of the complicated morphology of the reaction product in a lithium-oxygen battery. The results of this work not only answer the two questions outlined above, but also provide insight into ion and electron transport coupled with mass flow for the lithium-oxygen battery. More information: Langli Luo et al. Revealing the reaction mechanisms of Li–O2 batteries using environmental transmission electron microscopy, Nature Nanotechnology (2017). DOI: 10.1038/NNANO.2017.27


News Article | April 27, 2017
Site: www.greencarcongress.com

« California Assembly weighing integrating air pollution performance into GHG cap-and-trade | Main | IEA: Global oil discoveries and new projects fell to historic lows in 2016 while US shale surged; “two-speed” market » Lithium-air batteries are looked to by many as a very high-energy density next-generation energy storage solution for electric vehicles. However, the technology has several holdups, including losing energy as it stores and releases its charge.The reaction mechanisms are, in general, not well understood. One reaction that hasn’t been fully explained is how oxygen blows bubbles inside a lithium-air battery when it discharges. The bubbles expand the battery and create wear and tear that can cause it to fail. Now, researchers from Pacific Northwest National Laboratory (PNNL) have provided the first step-by-step explanation of how lithium-air batteries form bubbles. The paper is published in the journal The research was aided by a first-of-a-kind video that shows bubbles inflating and later deflating inside a nanobattery. Researchers had previously only seen the bubbles, but not how they were created. The performances of a Li–O battery depend on a complex interplay between the reaction mechanism at the cathode, the chemical structure and the morphology of the reaction products, and their spatial and temporal evolution; all parameters that, in turn, are dependent on the choice of the electrolyte. In an aprotic cell, for example, the discharge product, Li O , forms through a combination of solution and surface chemistries that results in the formation of a baffling toroidal morphology. In a solid electrolyte, neither the reaction mechanism at the cathode nor the nature of the reaction product is known. Here we report the full-cycle reaction pathway for Li–Obatteries and show how this correlates with the morphology of the reaction products. Using aberration-corrected environmental transmission electron microscopy (TEM) under an oxygen environment, we image the product morphology evolution on a carbon nanotube (CNT) cathode of a working solid-state Li–Onanobattery and correlate these features with the electrochemical reaction at the electrode. We find that the oxygen-reduction reaction (ORR) on CNTs initially produces LiO, which subsequently disproportionates into Liand O. The release of Ocreates a hollow nanostructure with LiO outer-shell and Liinner-shell surfaces. Our findings show that, in general, the way the released Ois accommodated is linked to lithium-ion diffusion and electron-transport paths across both spatial and temporal scales; in turn, this interplay governs the morphology of the discharging/charging products in Li–Ocells. Wang works out of EMSL, the Environmental Molecular Sciences Laboratory, a DOE Office of Science user facility located at PNNL. His co-authors include other PNNL staff and a researcher from Tianjin Polytechnic University in China. The team’s unique video was captured with an in-situ environmental transmission electron microscope at EMSL. Wang and his colleagues built their tiny battery inside the microscope’s column. This enabled them to watch as the battery charged and discharged inside. Video evidence led the team to propose that as the battery discharges, a sphere of lithium superoxide jets out from the battery’s positive electrode and becomes coated with lithium oxide. The sphere’s superoxide interior then goes through a chemical reaction that forms lithium peroxide and oxygen. Oxygen gas is released and inflates the bubble. When the battery charges, lithium peroxide decomposes, and leaves the former bubble to look like a deflated balloon. This finding was the focus of a Nature News & Views column written by researchers at Korea’s Hanyang University, who describe the research as “a solid foundation for future Li-O battery designs and optimization.” This research was supported by DOE’s Office of Energy Efficiency and Renewable Energy.


News Article | April 28, 2017
Site: www.cemag.us

With about three times the energy capacity by weight of today's lithium-ion batteries, lithium-air batteries could one day enable electric cars to drive farther on a single charge. But the technology has several holdups, including losing energy as it stores and releases its charge. If researchers could better understand the basic reactions that occur as the battery charges and discharges electricity, the battery's performance could be improved. One reaction that hasn't been fully explained is how oxygen blows bubbles inside a lithium-air battery when it discharges. The bubbles expand the battery and create wear and tear that can cause it to fail. A paper in Nature Nanotechnology provides the first step-by-step explanation of how lithium-air batteries form bubbles. The research was aided by a first-of-a-kind video that shows bubbles inflating and later deflating inside a nanobattery. Researchers had previously only seen the bubbles, but not how they were created. "If we fully understand the bubble formation process, we could build better lithium-air batteries that create fewer bubbles," notes the paper's corresponding author, Chongmin Wang, of the Department of Energy's Pacific Northwest National Laboratory. "The result could be more compact and stable batteries that hold onto their charge longer." Wang works out of EMSL, the Environmental Molecular Sciences Laboratory, a DOE Office of Science user facility located at PNNL. His co-authors include other PNNL staff and a researcher from Tianjin Polytechnic University in China. The team's unique video may be a silent black-and-white film, but it provides plenty of action. Popping out from the battery's flat surface is a grey bubble that grows bigger and bigger. Later, the bubble deflates, the top turning inside of itself until only a scrunched-up shell is left behind. The popcorn-worthy flick was captured with an in-situ environmental transmission electron microscope at EMSL. Wang and his colleagues built their tiny battery inside the microscope's column. This enabled them to watch as the battery charged and discharged inside. Video evidence led the team to propose that as the battery discharges, a sphere of lithium superoxide jets out from the battery's positive electrode and becomes coated with lithium oxide. The sphere's superoxide interior then goes through a chemical reaction that forms lithium peroxide and oxygen. Oxygen gas is released and inflates the bubble.  When the battery charges, lithium peroxide decomposes, and leaves the former bubble to look like a deflated balloon. This finding was the focus of a Nature News & Views column written by researchers at Korea's Hanyang University, who describe the research as "a solid foundation for future Li-O2 battery designs and optimization." This research was supported by DOE's Office of Energy Efficiency and Renewable Energy.


News Article | April 26, 2017
Site: www.eurekalert.org

RICHLAND, Wash. -- With about three times the energy capacity by weight of today's lithium-ion batteries, lithium-air batteries could one day enable electric cars to drive farther on a single charge. But the technology has several holdups, including losing energy as it stores and releases its charge. If researchers could better understand the basic reactions that occur as the battery charges and discharges, the battery's performance could be improved. One reaction that hasn't been fully explained is how oxygen blows bubbles inside a lithium-air battery when it discharges. The bubbles expand the battery and create wear and tear that can cause it to fail. A new paper in Nature Nanotechnology provides the first step-by-step explanation of how lithium-air batteries form bubbles. The research was aided by a first-of-a-kind video that shows bubbles inflating and later deflating inside a nanobattery. Researchers had previously only seen the bubbles, but not how they were created. "If we fully understand the bubble formation process, we could build better lithium-air batteries that create fewer bubbles," noted the paper's corresponding author, Chongmin Wang, of the Department of Energy's Pacific Northwest National Laboratory. "The result could be more compact and stable batteries that hold onto their charge longer." Wang works out of EMSL, the Environmental Molecular Sciences Laboratory, a DOE Office of Science user facility located at PNNL. His co-authors include other PNNL staff and a researcher from Tianjin Polytechnic University in China. The team's unique video may be a silent black-and-white film, but it provides plenty of action. Popping out from the battery's flat surface is a grey bubble that grows bigger and bigger. Later, the bubble deflates, the top turning inside of itself until only a scrunched-up shell is left behind. The popcorn-worthy flick was captured with an in-situ environmental transmission electron microscope at EMSL. Wang and his colleagues built their tiny battery inside the microscope's column. This enabled them to watch as the battery charged and discharged inside. Video evidence led the team to propose that as the battery discharges, a sphere of lithium superoxide jets out from the battery's positive electrode and becomes coated with lithium oxide. The sphere's superoxide interior then goes through a chemical reaction that forms lithium peroxide and oxygen. Oxygen gas is also released and inflates the bubble. When the battery charges, lithium peroxide decomposes, and leaves the former bubble to look like a deflated balloon. This finding was the focus of a Nature News & Views column written by researchers at Korea's Hanyang University, who describe the research as "a solid foundation for future Li?O2 battery designs and optimization." This research was supported by DOE's Office of Energy Efficiency and Renewable Energy. PAPER: Langli Luo, Bin Liu, Shidong Song, Wu Xu, Ji-Guang Zhang, Chongmin Wang, "Revealing the reaction mechanisms of Li-O2 batteries using environmental transmission electron microscopy," Nature Nanotechnology, March 27, 2017, doi:10.1038/nnano.2017.27, http://www. . Interdisciplinary teams at Pacific Northwest National Laboratory address many of America's most pressing issues in energy, the environment and national security through advances in basic and applied science. Founded in 1965, PNNL employs 4,400 staff and has an annual budget of nearly $1 billion. It is managed by Battelle for the U.S. Department of Energy's Office of Science. As the single largest supporter of basic research in the physical sciences in the United States, the Office of Science is working to address some of the most pressing challenges of our time. For more information on PNNL, visit the PNNL News Center, or follow PNNL on Facebook, Google+, Instagram, LinkedIn and Twitter. EMSL, the Environmental Molecular Sciences Laboratory, is a DOE Office of Science User Facility. Located at Pacific Northwest National Laboratory in Richland, Wash., EMSL offers an open, collaborative environment for scientific discovery to researchers around the world. Its integrated computational and experimental resources enable researchers to realize important scientific insights and create new technologies. Follow EMSL on Facebook, LinkedIn and Twitter.


A method for preparing a reinforced electrospinning nanofiber membrane, which performs alternate blending electrospinning by utilizing several thermoplastic polymer with a melting point at least 20C lower than that of the other component or thermoplastic polymer with low melting point, and non-thermoplastic polymer. Electrospun jets of several components are arranged along the movement direction of receiving device in forth-and-back, fibers are arranged randomly and alternatively. The blending spinning fiber membrane is post-treated with thermal calendering, and the hot-pressing temperature is slightly higher than that of starting melting temperature of the polymer with low melting point, time is 110 min, pressure is 120 MPa. After hot-pressing, the thermoplastic polymer with low melting point is partly melt and forms point bonding at the intersection of fibers, without clogging pores. This invention relates to an electrospun nanofiber membrane and a blending electrospinning device.


Disclosed in the present invention is a benzocrown ether graft polymer with a lithium isotopic separation effect and a preparation method thereof. The polymer is a benzocrown ether graft polymer formed by the linkage of chemical bonds, which takes the main chain of a polymer containing chloromethyl group, chloroformyl group or hydroxyl group as main chain, and takes a benzocrown ether as pendant group. The preparation process of the polymer comprises the following steps: preparing polymer solution with certain concentration by dissolving a polymer containing chloromethyl group, chloroformyl group or hydroxyl group in a solvent; then blending a catalyst and a benzocrown ether containing carboxyl group or aldehydyl group and dissolving in the polymer solution containing hydroxyl group, or blending an acid-binding agent and a benzocrown ether containing amino group or hydroxyl group and dissolving in the polymer solution containing chloromethyl group or chloroformyl group, reacting at a certain temperature and for a certain time, linking the benzocrown ether to the main chain of polymer by chemical bonds, and precipitating by adding a precipitating agent to obtain the graft polymer. The grafting polymer has excellent characteristic of lithium isotopic separation.


Patent
Tianjin Polytechnic University | Date: 2013-03-21

The present invention provides a thermo-regulated fiber and a preparation method thereof by using a new polymeric phase-change material and adopting a new fiber preparation method, and the resulting thermo-regulated fiber has good thermo-regulating properties and a good thermal stability. The thermo-regulated fiber has a composite structure, and the cross-sectional structure is an sea-island type or a concentric sheath/core type, characterised in that the polymeric phase-change material is a polyethylene glycol n-alkyl ether (structural formula: H(OCH_(2)CH_(2))_(m)OC_(n)H2_(n+1)), where the repeating unit number m of the ethylene glycol is 1 to 100, the number n of carbon atoms in the n-alkyl is 11 to 30. The present invention further relates to a preparation method of a thermo-regulated fiber which includes one of the following processes: (1) A melt composite spinning process; (2) Solution composite spinning process; (3) Electrostatic solution composite spinning process. Further, the present invention is characterised as follows: (1) a new polymeric phase-change material polyethylene glycol n-alkyl ether is used; (2) Component A of the thermo-regulated fiber may form a continuous crystallization region; (3) The thermo-regulated fiber can be prepared in various forms by many preparation methods such as melt composite spinning, solution composite spinning and solution static composite spinning.


Patent
Tianjin Polytechnic University | Date: 2014-10-28

A hollow tubular oil absorbing material includes: a core formed by a spring, and an outer shell formed by a flat sponge wrapped at the spring; wherein the flat sponge is fixed at both ends of the spring; the flat sponge fully covers all the spring or is sealed at a first end; a connecting tube is connected at a second end of the spring for communicating with a vacuum pump; a graphene oxide layer is coated at the outer sponge. The graphene oxide layer on the flat sponge of hollow tubular oil absorbing material is formed by immersion and coating under negative pressure. Further the reduction of graphene oxide is performed with hydrazine hydrate steam and followed by washing and drying. Finally, a hollow tubular oil absorbing material with a spring core and an outer grapheme-coated sponge structure is obtained, which can be applied to continuous oil-water separation.


Patent
Tianjin Polytechnic University | Date: 2016-11-23

A method for preparing a homogeneous braid-reinforced (HMR) PPTA hollow fiber membrane combines PPTA hollow tubular braids with PPTA surface separation layer. The method includes following steps of: (1) preparing the PPTA hollow tubular braids, wherein the PPTA hollow tubular braids which are made from PPTA filament yarns are woven by a two-dimensional braided method, the outer diameter of the PPTA tubular braids is 1-2mm; (2) preparing the PPTA casting solution as the surface separation layer, wherein the 1-3wt% PPTA resin, 0-2wt% inorganic particles and 10-20wt% pore-forming agents are mixed into 75-89% inorganic acid solvent, stirred for 1-3 hours at 70C-90C to form homogeneous and transparent casting solution; and (3) preparing reinforced PPTA hollow fiber membrane, wherein the casting solution as the surface separation layer is evenly coated on the surfaces of the PPTA hollow tubular braids through spinneret, and they are immersed in a coagulation bath for solidified formation.

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