Molecular Reactivity and Interface Stability Modification in In-Situ Gel Electrolyte for High Performance Quasi-Solid-State Lithium Metal Batteries

Quasi-solid-state lithium metal battery is a promising candidate for next generation high energy density and high safety power supply.Despite intensive efforts on electrolytes,uncontrolled interfacial reactions on lithium with electrolyte and patchy interfacial contacts still hinder its practical process.Herein,we bring in rationally designed F contained groups into polymer skeleton via in-situ gelation for the first time to establish quasi-solid-state battery.This method achieves a capacity retention of 90%after 1000 cycles at 0.5C with LiFePO_(4)cathodes.The interface constructed by polymer skeleton and reaction with–CF_(3)lead to the predicted solid electrolyte interface species with high stability.Furthermore,we optimize molecular reactivity and interface stability with regulating F contained end groups in the polymer.Comparisons on different structures reveal that high performance solid stable lithium metal batteries rely on chemical modification as well as stable polymer skeleton,which is more critical to construct robust and steady SEI with uniform lithium deposition.New approach with functional groups regulation proposes a more stable cycling process with a capacity retention of 94.2%at 0.5C and 87.6%at 1C after 1000 cycles with LiFePO_(4) cathodes,providing new insights for the practical development of quasi-solid-state lithium metal battery.

Preparation Process of Plumbagin Nanomicelle In-situ Gel

[Objectives]To prepare plumbagin nanomicelle(PLB-N)in-situ gel,and optimize the formulation and process.[Methods]PLB-N was prepared by self-assembly method,and the optimal formulation of PLB-N in-situ gel was determined by orthogonal experiment design and single factor method.[Results]The optimal preparation process for PLB-N was a drug to lipid ratio of 1:3,a Tween 80 content of 5%,an ethanol content of 7.5%of the hydration medium,a magnetic stirring speed of 2200 rpm,a stirring time of 30 min,and an ultrasound time of 10 min.The optimal formulation of PLB-N in-situ gel was 22%of poloxamer 407,6%of poloxamer 188,and 1:1 of PLB-N to water.The encapsulation efficiency of PLB-N prepared with the optimal formula was(95.8%±0.4%),and the average particle size was(75.19±1.14)nm,and the Zeta potential was(-20.73±1.19)mv.[Conclusions]PLB-N in-situ gel had stable and reliable preparation process,uniform content,and broad application prospects.

Research progress of in-situ gelling ophthalmic drug delivery system

Blindness and vision impairment are the most devastating global health problems resulting in a substantial economic and social burden.Delivery of drug to particular parts of the anterior or posterior segment has been a major challenge due to various protective barriers and elimination mechanisms associated with the unique anatomical and physiological nature of the ocular system.Drug administration to the eye by conventional delivery systems results in poor ocular bioavailability(<5%).The designing of a novel approach for a safe,simple,and effective ocular drug delivery is a major concern and requires innovative strategies to combat the problem.Over the past decades,several novel approaches involving different strategies have been developed to improve the ocular delivery system.Among these,the ophthalmic in-situ gel has attained a great attention over the past few years.This review discussed and summarized the recent and the promising research progress of in-situ gelling in ocular drug delivery system.

Disulfiram thermosensitive in-situ gel based on solid dispersion for cataract

To improve the corneal permeability and water-solubility of disulfiram(DSF), which is an ocular drug for cataract, P188 was selected as a matrix to prepare solid dispersion of DSF(DSF SD) by hot melt method. The DSF SD was characterized by DSC, XRD, and IR, and the results suggested that DSF was amorphous in DSF SD. The DSF SD was added to borate buffer solution(BBS) contained 20% poloxamer P407 and 1.2% poloxamer P188 to form in-situ gel. In vitro and in vivo experiments revealed that DSF SD combined with in-situ gel(DSF SD/in-situ gel) increased the residence time and the amount of DSF penetrated through the corneal. The pharmacodynamics studies exhibited DSF SD/in-situ gel delayed the development of selenium-induced cataract at some content. These results investigated that DSF SD/in-situ gel as a drug delivery system can improve DSF ocular permeability.

Study of pressure effects on ocean in-situ detection using laser-induced breakdown spectroscopy

Laser-induced breakdown spectroscopy(LIBS) has attracted extensive attention as a new technique for in-situ marine application. In this work, the influence of deep-sea high pressure environment on LIBS signals was investigated by using a compact LIBS-sea system developed by Ocean University of China for the in-situ chemical analysis of seawater. The results from the field measurements show that the liquid pressure has a significant effect on the LIBS signals. Higher peak intensity and larger line broadening were obtained as the pressure increases. By comparing the variations of the temperature and salinity with the LIBS signals, a weak correlation between them can be observed. Under high pressure conditions, the optimal laser energy was higher than that in air environment. When the laser energy exceeded 17 mJ, the effect of laser energy on the signal intensity weakened. The signal intensity decreases gradually at larger delays. The obtained results verified the feasibility of the LIBS technique for the deep-sea in-situ detection, and we hope this technology can contribute to surveying more deep-sea environments such as the hydrothermal vent regions.

A comprehensive review of in-situ polymer gel simulation for conformance control

Gel treatment has been widely applied in mature oilfields to improve sweep efficiency and control water production.Correct numerical simulation is of major importance to the optimization design and prediction of a successful gel treatment.However,there exist many problems in current simulation studies in published literature.This paper first presents a comprehensive review on the major factors that have been considered at different gelation stages during gel treatment,the models used in the commercial/inhouse simulators,and current numerical simulation studies on both laboratory and field scales.Then we classify the current in-situ gel numerical simulation problems as 1,deficient model problem that has published numerical model but has not been applied in simulator and application studies;2,missing model problem that does not have published quantitative model;and 3,inaccurate application problem that does not consider the major factors of gel performance,based on the reasons from some questionable results of current simulation studies.Finally,we point out the major research efforts that should be made in the future to better simulate in-situ gel treatment process.The review indicates that numerous simulation studies using commercial software packages intend to predigest the gel treatment,many of which,however,ignore important mechanisms and mislead the operation of gel treatment.In fact,a full assessment of simulating in-situ gels cannot be achieved unless the quantitative models can be qualified in terms of transport and plugging mechanisms based on the experimental results.

IGBT灌封用苯基改性有机硅凝胶的耐热及介电性能研究

随着绝缘栅双极型晶体管(insulated gate bipolar transistor,IGBT)向高电压、大功率化方向发展,其产生的热量和运行温度快速上升,致使其绝缘封装系统失效问题愈发突出。为满足IGBT日益严苛的工作环境,亟需研发一种高性能的有机硅灌封材料。该文通过化学合成制备苯基改性有机硅凝胶(phenyl modified silicone gel,PMSG),研究其耐热和介电性能。结果表明:PMSG失重5%的热失重温度为383℃,室温击穿场强可达32.62 kV/mm,比纯有机硅凝胶(pure silicone gel,PSG)提高17.42%,且150℃击穿场强相较于室温击穿场强仅下降25.38%,展现出更优良的高温耐电特性。同时,其相比于PSG具有更低的介电损耗。因此,PMSG作为IGBT封装材料时,整体性能更加优良。该研究将为IGBT封装用新型高性能绝缘材料的研制提供有效思路和理论基础。

Study on an novel composite gel material solving serious lost circulations and pressurization sealing

Lost circulations have presented great challenges to the petroleum industry, causing great expenditures of cash and time to fighting the problem. Probably the most problematic situations are the naturally fractured formations where the operator may face total loss with no mud return in the annular. The voids or large fracture encountered in this case are often far too large to be plugged with conventional Lost Circulation Material. This paper will give a detailed introduction on a novel composite gel material usable to control severe losses and pressurization sealing. The plugging mechanics of this new composite gel material, which is different from conventional lost circulation materials, were elaborated as well. In addition, the properties of the new composite gel material such as thermostability, sealing strength and bearing resistance are characterized with specific experimental devices. The experimental results proved that the breakdown pressure of the new plugging reached more than 20MPa, and the maximum degraded temperature can be exceed 130℃. The field application at 4 wells in Puguang gas field, SINOPEC, demonstrated that the new composite gel material solved the serious loss in Ordovician carbonate fractured formation successfully and guaranteed the following completion cement operation smoothly. The composite gel sealing slurries, which was easily prepared on site, gives remarkable properties regarding pumping through drill pipes, adjustment of setting time and excellent sealing strength of the lost zone sealing, additionally, the whole pressurization sealing process was complicated within only ten hours. The on-site results show that the plugging ratio of the new composite gel was reached 100%, and the success rate of sealing operation kept above 80%.Thus the new LCM can guarantee safe drilling jobs and save operation cost more effectively.

SiO_(2) nanofiber composite gel polymer electrolyte by in-situ polymerization for stable Li metal batteries

Gel polymer electrolytes(GPEs) are promising alternatives to liquid electrolytes applied in high-energydensity batteries.Here superior SiO_(2) nanofiber composite gel polymer electrolytes(SNCGPEs) are developed via in-situ ionic ring-opening polymerization of 1,3-dioxolane(DOL) monomers in SiO_(2) nanofiber membrane(PDOL-SiO_(2)) for lithium metal batteries.The oxygen atoms of PDOL together with Si-O of SiO_(2) construct a more efficient channel for Li^(+) migration.Consequently,the lithium ion transference number(t_(Li^(+)) and ionic conductivity(σ) at 30℃ of PDOL-SiO_(2) are 0.80 and 1.68×10^(-4)S/cm separately.PDOL-SiO_(2) manifests the electrochemical decomposition potentials of 4.90 V.At 0.5 mA/cm^(2),Li|PDOL-SiO_(2) |Li cell shows a steady cycling performance for nearly 1400 h.LFP|PDOL-SiO_(2) |Li battery can steadily cycle at 0.5 C with a capacity retention rate of 89% after 200 cycles.While cycling at 2 C,the capacity retention rate can maintain at 78% after 300 cycles.This contribution provides a innovative strategy for accelerating Li^(+)transportation via designing PDOL molecular chains throughout the SiO_(2) nanofiber framework,which is crucial for high-energy-density LMBs.

微胶囊缓释破胶剂的室内研制

采用滚动造粒法在过硫酸铵颗粒外包一层高分子粉体，再采用Ｗｕｒｓｔｅｒ流化床法将颗粒包封，制成了微胶囊缓释破胶剂，在室内实验装置上产率达９０％以上。所得微胶囊破胶剂具有良好的延迟释放、延迟破胶性能。有两个样品７０℃时延迟释放时间分别达４８ｍｉｎ和６５ｍｉｎ，释放５０％的时间分别为２０８ｍｉｎ和３１２ｍｉｎ。在冻胶体系中加入其中一个样品，加量０．１４ｇ／ｌ（以所含过硫酸铵计），在７０℃放置９０ｍｉｎ后冻胶体系粘度损失仅８％。

长庆油气田压裂用生物酶破胶技术及其应用

利用核磁共振技术研究了用APS破胶的硼交联瓜尔胶压裂液对长庆低渗岩心的伤害机理，认为主要伤害因素是压裂液的黏滞力和大分子聚合物。指出了长庆油气田使用APS破胶的不足之处。基于引进产品开发了酶破胶剂GLZ-1，该剂含β-1，4-和α-1，6-糖苷键特异水解酶，可将半乳甘露聚糖最终分解为单糖和二糖。根据酶活力测定，该剂适用温度范围为40-90℃，适用pH范围为6～10，盐度在2％～10％范围内对酶活力基本上无影响，该剂与压裂液添加剂配伍。与APS相比，破胶液残渣含量较低，破胶液滤液中总含糖量较高且随破胶时间的升幅较大，4、24、48h破胶液中聚糖相对分子质量（M）主要分布区域分别为1300～5500、1200-4800、250～3800，而用APS破胶时，破胶液中检测不到M〈5000的聚糖分子。GLZ-1破胶液对岩心渗透率的伤害小于20％，而APS破胶液的伤害为27．7％～30．2％。在鄂尔多斯盆地苏力格气田8口井、西峰油田20口井压裂中使用GLZ-1破胶，油井返排液黏度〈2mPa·s，返排率〉65％，气田一次喷通，返排液黏度〈3mPa·s，平均返排率90．2％。图1表6参3。

有效降解PRD钻井液的低温破胶剂JPC室内研究

用PRD聚合物钻井液钻井完钻后，须对井筒内余留的钻井液实施破胶处理，以免钻井液污染地层。常用的氧化荆破胶法低温破胶效果差。本文报道低温破胶刑JPC的实验研究结果。实验钻井液（胶液）为0．65％PF-VIS增粘的PRD钻井液。用破胶率即以空白处理胶液为基准的破胶剂处理胶液表观粘度降低率表示破胶效果。在包括强氧化性酸、盐、碱的9种化学（生化）刑中，JPC的50℃、4h破胶率最高，为95．2％（加量1．0％），α-葡糖酶次之,为72．1％（加量1．5％），其余均低于50％。JPC的破胶率随加量增大而增大，加量≥1．5％时趋于恒定，适宜加量为2．0％；破胶温度升高（21-95℃）或破胶时间延长（0.5～5．0h）时破胶率增大，加量2．0％、50℃、3h破胶率超过90％，破胶液21℃表现粘度为4．0mPa·s。JPC对储层无伤害，注入2．0％的JPC海水溶液4．5PV时，南海西江23—1油藏岩心渗透率不降低，油相渗透率在注入煤油7．0PV时完全恢复。图3表3参2。

聚合物降解产物伤害与糖甙键特异酶破胶技术

综述了钻井、完井、尤其是水力压裂作业中产生的多糖类聚合物伤害和应用糖甙键特异酶破胶、解除多糖类聚合物伤害的技术。第一节报道了聚合物降解产物造成的伤害 ,指出冻胶破胶液粘度低并不代表压裂液已从充填裂缝中充分返排 ,氧化破胶剂和普通酶破胶剂不能使多糖类聚合物充分降解 ,产生的大分子量的、水不溶的降解产物可对地层造成伤害 ,消除伤害的办法是采用对糖甙键有特异性的各种水解酶作压裂液破胶剂或伤害地层处理剂。第二节报道了各种聚合物 (纤维素、瓜尔胶、淀粉 )糖甙键特异酶降解聚合物的机理。第三节报道了糖甙键特异酶 (主要针对瓜尔胶 )的应用性能测试及结果 ,包括岩心流动实验、含糖量和分子量测定、传导性测试。第四节介绍了糖甙键特异酶消除聚合物伤害和用作压裂液破胶剂的现场应用 ,包括选井原则、实施工艺要点及 3个典型井例。

植物胶液体胶塞CQTD-95及其暂堵技术研究

植物胶液体胶塞CQTD-95由稠化剂CQTD-95基液与专用交联剂CL-80反应生成。调化剂CQTD-95为经多次化学加工的羟丙基瓜尔胶，在水中分散而不溶解，与CL-80混合后在1-15分钟内形成凝胶。本文报道稠化剂CQTD-95的制备。基液粘度、胶塞相对强度、影响胶塞形成及其强度的配方因素、盐酸对胶塞的破坏等室内研究结果，以及在大直径试验井内用大型模拟试验装置考察胶塞从射孔眼、裂缝、填砂层挤出的性能和用盐酸使剩余胶塞破胶的结果。CQTD-95的性能与美国Phillips公司的Tempgel相当。

超低浓度羟丙基瓜胶压裂液在煤层气储层改造中的应用

开发了一种适用于煤层气储层改造的超低浓度羟丙基瓜胶压裂液的交联剂GJ-1,其具有长链多交联点螯合能力、交联网络密集、交联时间短、冻胶的黏弹性较好等性能;过硫酸铵和低温酶复合体系实现了低温高效破胶。从黏度、伤害等方面进行综合评价,结果表明,0.15%改性羟丙基瓜胶GJ与0.3%交联剂GJ-1组成的交联体系交联速度快,伤害率较低。控制低温酶和APS加量可以将破胶时间调节在2-8 h内且可控,破胶后残渣只有33 mg/L,有效减小对煤层裂缝导流能力的损害。现场应用表明,这种超低浓度羟丙基瓜胶压裂液体系的加砂量达到了设计要求,压后返排液破胶良好。

微胶囊缓释破胶剂MEB-1的制备及性能

将含有一种聚合单体的过硫酸铵饱和水溶液分散在三氯甲烷中,在50℃反应3～4小时,滤出,以无水乙醇洗涤,干燥,得到囊壁为水溶胀性聚合物的微胶囊破胶剂MEB-1。该剂粒径0.5～0.9mm,过硫酸铵有效含量可达39.23%,包埋率86.77%,释放率>60%,推荐使用温度60～130℃。MEB-1的过硫酸铵释放率随温度(30～120℃)和时间(10～60min,90℃)的变化,加量0.1%时0.6%HPG/有机硼压裂液90℃黏度变化和90℃破胶性能,均与两种商品微胶囊破胶剂(LZEN-1和-2)相近或相同,加入0.1%MEB-1的该压裂液80℃时对地层岩心渗透率(0.0178～0.0187μm2)的伤害较小,仅为14.8%,加入两种对比剂的压裂液则分别为17.7%和18.1%。

纤维压裂液及其在吉林油田的应用

针对油气生产过程中容易出砂和压后测试快速排液时出现的支撑剂回流等问题,采用纤维稳定支撑剂技术配制出了性能优良的纤维压裂液,对该压裂的性能进行了系统评价,并介绍了纤维压裂液在吉林油田的应用情况。通过考察纤维加量(0.1%～0.4%)对压裂液黏度及交联时间的影响,得到了纤维压裂液配方:0.3%瓜尔胶+0.04%SD2-2有机硼交联剂+0.035%过硫酸铵+0.2%T-3纤维+其他添加剂,该纤维压裂液pH值9～10,稳定性良好,并具有良好的延迟交联性能和耐剪切性能,适合于60～65℃的中低温地层。当闭合压力小于20 MPa时,加入纤维的支撑剂导流能力不受影响;常温、170 1/s下连续剪切90 min后黏度保留率为52.86%;破胶水化液的表面张力为23.8 mN/m并且黏度小于5 mPa.s。该项技术在吉林扶余油田东+5-33、东34-201、松原采气厂老4-24井共3口井进行现场施工中取得了良好应用效果。

支撑裂缝处理剂性能研究与应用

研制了一种支撑裂缝处理剂 ,在实验室考察了该处理剂的应用性能 ,并在 3口井上进行了成功的应用试验。该处理剂为含有氧化剂、助氧化剂、催化剂的水溶液 ,用于处理加砂压裂后的支撑剂充填裂缝 ,破解裂缝内压裂液冻胶 ,溶解压裂液残渣和聚合物滤饼 ,以改善破胶液返排效果 ,提高裂缝导流能力。室内性能考察结果表明 ,与使用过硫酸铵破胶相比 ,该处理剂在≥ 4 0℃破胶迅速 ,破胶液粘度很低 (～ 1mPa·s) ,可使压裂液残渣产生量减少73 %以上 ,可完全溶解常规破胶法产生的残渣 ,使导流能力提高 4 0 %以上 ,对支撑剂的强度无影响。在 3口油井试用 ,压裂液平均返排时间比一口对比井缩短约 60 % ,平均返排率为 86.8% ,比对比井提高近 2 0 %。

乙丙橡胶电线电缆绝缘层耐电击穿性能的影响因素

研究了三元乙丙橡胶(EPDM)的第三单体(ENB)含量、纯净度、凝胶含量及加工配方对加工成品耐电击穿性能的影响。实验结果表明,加工过程中,ENB的交联越充分,残留的双键越少,加工成品的耐电击穿性能越好;EPDM的纯净度越高、凝胶含量越低,加工成品的耐电击穿性能越好;此外,与基础配方相比,经过优化后的配方也可以显著提高EPDM加工成品的耐电击穿性能。

可降解纤维压裂液的破胶性能实验研究

所报道的可降解纤维为一种有机酸酯聚合物,可在高温下水解降解而释出酸,在压裂液中既具有降阻、防止支撑剂回流、降滤等纤维功能,又能促进破胶。加入该种纤维的模拟压裂液(不含增稠剂和破胶剂),在80℃和120℃下的pH值随时间延长而降低,降低幅度随温度升高和纤维加量增大(0～2.7g/L)而增大,纤维加量1.8g/L时,在80℃经过100h或在120℃经过30h,pH可降至5.5。有机硼交联0.45%HPG压裂液,加入过硫酸铵100或300mg/L并在100℃放置24h后,破胶残渣量为428或315mg/L,破胶液pH值为9.2或8.5,而加入可降解纤维1.8g/L的压裂液,破胶残渣量减至203或112mg/L,破胶液pH值降至4.5或3.7。以抗氧化剂稳定的有机硼交联0.45%HPG压裂液,120℃、1701/s黏度随剪切时间延长而下降,但剪切70min的黏度高于200mPa.s,可满足中等规模的加砂压裂,剪切105min后降低温度,则黏度迅速回升,出现返胶现象。只加入该种纤维而未加破胶剂的压裂液,破胶返排后可再利用。