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New insights into hydraulic fracturing fluids used for hightemperature wells

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Petroleum 2021年第1期7卷 70-79页

作者： Tariq Almubarak Leiming Li Jun Hong Ng Hisham Nasr-El-Din Mohammed AlKhaldi Texas A&M University USA Aramco Services Company Saudi Arabia Saudi Aramco EXPEC ARC Saudi Arabia

Current interest in deep,low-permeability formations(<10 md)demands accelerated development of high-temperature hydraulic fracturing *** guar systems break down above 300°F and require higher polymer loadings to main... 详细信息

Current interest in deep,low-permeability formations(polymer loadings to maintain thermal ***,higher polymer loadings generate more residue and damage to the proppant pack and the *** resolve these problems,a variety of high-temperature stabilizers are added to enhance the thermal stability of these fracturing fluids at temperatures above 300*** focus of this work is to:(1)identify those additives that best enhance temperature stability of fracturing fluids and(2)study the rheological influence of incorporating these additives on the fracturing fluid *** experimental fracturing-fluid solutions were prepared at a total polymer concentration of 30 and 40 lb/1000 *** such as synthetic polymer,oxygen scavengers,crosslinkers,crosslinker delay additives,and pH buffers were examined in this *** polymer solutions were crosslinked with a metallic crosslinker between 200 and 400°*** measurements were carried out in a highpressure/high-temperature(HP/HT)rheometer to evaluate rheology and thermal *** show that adding a synthetic polymer and a crosslinker with the slowest reaction rate improves the fracturing fluid thermal *** the three other additives tested,oxygen scavengers showed the greatest enhancement to thermal stability while pH buffers showed the *** the addition of high-temperature stabilizing additives,the fracturing fluid in this work was able to maintain a stable performance at temperatures up to 400°*** the thermal stability of fracturing fluids at a lower polymer loading remains a challenge in the *** work proposes techniques that can be used to enhance the thermal stability of fracturing *** knowledge about these different techniques will allow for better additive development and a

关键词： Oxygen scavenger Crosslinker Crosslinker delay Shear tolerance High temperature synthetic polymer CMHPG Buffers

Biomaterials for refractive correction:corneal onlays and inlays

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Science China Chemistry 2014年第4期57卷 501-509页

作者： WU Jian FUNDERBURGH James L WAGNER William R McGowan Institute for Regenerative Medicine University of Pittsburgh Department of Surgery University of Pittsburgh School of Medicine Department of Ophthalmology University of Pittsburgh School of Medicine Department of Bioengineering University of Pittsburgh

Corneal inlays and onlays represent a means of providing patients with permanent refractive error correction. As an alternative to conventional spectacles and contact lens, these techniques are less invasive compared with laser-based refractive surgery and are reversible. In this review, we provide a brief overview of the anatomic microstructure of the human cornea, indicating the primary physiological function for each component. Next, the wide range of biomaterials used as corneal inlays and onlays are considered, from synthetic polymers to biological components derived from the extracellular matrix. The limitations and challenges associated with the most common materials are discussed as is the need to improve their properties to achieve long-term, complication-free intraocular implantation. Finally, the prospect of applying tissue engineering strategies is noted for its potential to generate autologous corneal tissue that could be implanted as the optimal inlay or onlay materials.

关键词： refractive error onlays inlays synthetic polymer biological extracellular matrix refractive surgery

Preparation of a gene-engineering mutant of bacteriorhodopsin BR-D96V and corresponding poly(vinyl alcohol)-based functional composite films

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Science Bulletin 2010年第33期 3829-3834页

作者： ZHAO YingChun1,2,MING Ming1,HONG Jie2,MA DeWang1,WU Jia1,LI QingGuo3,HUANG WeiDa2 & DING JianDong1 1 Key Laboratory of Molecular Engineering of polymers of Ministry of Education,Department of Macromolecular Science,Fudan University,Shanghai 200433,China 2 Department of Biochemistry,School of Life Sciences,Fudan University,Shanghai 200433,China 3 Department of Physiology and Biophysics,School of Life Sciences,Fudan University,Shanghai 200433,China

Bacteriorhodopsin(BR)exhibits,as a membrane protein in Halobacterium salinarum,unique photoresponsive behaviors,and shows promise as a functional information material.A new mutant of BR with the 96th aspartic acid replaced by valine(BR-D96V)was obtained and then a composite film of BR-D96V in a synthetic polymer matrix was prepared in this *** mutant BR-D96V was expressed in a bacterio-opsin deficient halobacterial strain(L33)by gene *** valine is very hydrophobic,this point mutant keeps the basic biological activities,namely,photoelectric and photochromic ***,the lifetime of M intermediate in the BR mutant is nearly two orders of magnitude longer than that of wild-type BR in neutral aqueous solution,which benefits its potential application as an information *** M lifetime is further significantly prolonged after embedding BR-D96V into poly(vinyl alcohol)(PVA).It was also found that BR-D96V is very sensitive to water content in comparison with wild-type BR and another BR mutant.

关键词： synthetic polymer organic photoelectric material composite film bacteriorhodopsin site-specific mutagenesis photore-sponsive protein

A review of polymer-derived hard carbon materials as an anode material in sodium-ion batteries

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分子科学学报 2024年第4期40卷 283-299页

作者： LIU Jiaxin YUAN Wenyi SUN Zhipeng College of Materials and Energy Guangdong University of TechnologyGuangzhou 510006China

This paper describes the sodium storage mechanism of hard carbon,including the insertion-adsorption model,adsorption-insertion model,adsorption-filling model,and adsorption-insertion-filling *** research progress of hard carbon prepared by synthetic polymers in recent years is *** modification strategies of morphology and structure regulation,surface engineering,defect engineering,heteroatom doping,and pretreatment are proposed to improve the electrochemical performance of hard carbon materials and promote the research and development of hard carbon as anode materials for sodium-ion batteries.

关键词： sodium-ion battery hard carbon synthetic polymer sodium storage mechanism improvement method