离子液体催化苯酚与叔丁醇烷基化反应

 研究了SO₃H-功能化离子液体的合成、表征及其催化苯酚与叔丁醇(TBA)烷基化反应的性能. 考察了反应时间t、反应温度T、反应物摩尔比及离子液体(IL)用量等因素对反应性能的影响, 并考察了离子液体的重复使用性能. 结果表明, 在T=70℃、t=420min、n(Phenol):n(TBA):n(IL)=1:1:1的优化反应条件下, 苯酚的转化率可以达到79.6%, 邻-叔丁基苯酚的选择性达到了52.4%. 离子液体重复使用4次, 其活性基本不变.     

Effect of reactor configuration on the yields and structures of pine-wood derived pyrolysis liquids: A comparison between ablative and wire-mesh pyrolysis

Product distributions from the pyrolysis of a common sample of pine-wood have been determined for two reactors with different configurations. The ablative pyrolysis reactor operates on the principle of “scraping” a continuous stream of biomass particles onto a heated surface under conditions of high relative motion and high applied pressure. In the wire-mesh reactor configuration, fine dispersion of a small quantity [4–6 mg] of sample and the rapid removal of volatiles from the reaction zone ensures that volatiles released during pyrolysis are captured under conditions minimising extra particle secondary reactions.

Comparison of liquid yields determined for the two reactors has been undertaken in order to assess the effect of secondary reactions on yields during ablative pyrolysis. Structural characterisations and comparison of liquids produced in the two reactors have been carried out by size exclusion chromatography, UV-fluorescence spectroscopy and FTIR spectroscopy. Slight differences in structures were apparent either due to cracking of lignin-derived macromolecules on the heated reactor surface or low molecular weight components formed during slow pyrolysis reactions of a small proportion of the feed material. Comparison of the ablative liquids with those from other ablative pyrolysis reactors show similar trends in molecular mass distributions and structures suggesting that the ablative pyrolysis process inherently cracks some liquids during volatilisation. Dry organic liquid yields from the ablative pyrolysis reactor were between 2.5 and 5.3% lower than the wire-mesh reactor between 55° and 600°C. This is believed to be a result of non-optimised reactor operation of the ablative pyrolysis reactor.     

High-Gain Chemically Gated Organic Electrochemical Transistor

Organic electrochemical transistors (OECTs) have exhibited promising performance as transducers and amplifiers of low potentials due to their exceptional transconductance, enabled by the volumetric charging of organic mixed ionic/electronic conductors (OMIECs) employed as the channel material. OECT performance in aqueous electrolytes as well as the OMIECs’ redox activity has spurred a myriad of studies employing OECTs as chemical transducers. However, the OECT's large (potentiometrically derived) transconductance is not fully leveraged in common approaches that directly conduct chemical reactions amperometrically within the OECT electrolyte with direct charge transfer between the analyte and the OMIEC, which results in sub-unity transduction of gate to drain current. Hence, amperometric OECTs do not truly display current gains in the traditional sense, falling short of the expected transistor performance. This study demonstrates an alternative device architecture that separates chemical transduction and amplification processes on two different electrochemical cells. This approach fully utilizes the OECT's large transconductance to achieve current gains of 10³ and current modulations of four orders of magnitude. This transduction mechanism represents a general approach enabling high-gain chemical OECT transducers.     

A Highly Sensitive,Reversible, and Bidirectional Humidity Actuator by Calcium Carbonate Ionic Oligomers Incorporated Poly(Vinylidene Fluoride)

Sensitivity and multi-directional motivation are major two factors for developing optimized humidity-response materials, which are promising for sensing, energy production, etc. Organic functional groups are commonly used as the water sensitive units through hydrogen bond interactions with water molecules in actuators. The multi-coordination ability of inorganic ions implies that the inorganic ionic compounds are potentially superior water sensitive units. However, the particle forms of inorganic ionic compounds produced by classical nucleation limit the number of exposed ions to interact with water. Recent progress on the inorganic ionic oligomers has broken through the limitation of classical nucleation, and realized the molecular-scaled incorporation of inorganic ionic compounds into an organic matrix. Here, the incorporation of hydrophilic calcium carbonate ionic oligomers into hydrophobic poly(vinylidene fluoride) (PVDF) is demonstrated. The ultra-small calcium carbonate oligomers within a PVDF film endow it with an ultra-sensitive, reversible, and bidirectional response. The motivation ability is superior to other bidirectional humidity-actuators at present, which realizes self-motivation on an ice surface, converting the chemical potential energy of the humidity gradient from ice to kinetic energy.     

离子液体在片式铝电解电容器中的应用研究

利用离子液体具有的高热稳定性、高离子电导率的特点,选用了几种离子液体用作片式铝电解电容器工作电解液。性能测试结果表明,以马来酸或邻苯二甲酸的1,3-二烷基取代的咪唑盐或四氢吡咯盐的离子液体为电解质,所制成的电容器能通过105℃1000h寿命试验和耐回流焊接热试验。但电解液的闪火电压与传统电解液相比较低,一般只能做50V以下的低压电容器产品。     

Electrical Conduction and Disorder in the Pyrochlore System (Gd1−xCax)2Sn2O7

Electrical conductivity measurements were made on the pyrochlore compounds (Gd₁–_xCa_x)₂Sn₂O₇ (x =0, 0.0036, 0.0057, 0.03) as a function of temperature, oxygen partial pressure and Ca doping concentration. An effective Frenkel constant and oxygen vacancy mobility were derived. Intrinsic anion disorder was found to be lower than the expected value based on the relative radii of the cations in the A and B sites (A₂B₂O₇). Low oxygen vacancy mobilities as well as low anion disorder resulted in considerably lower ionic conductivities in Gd_sSn₂O₇ relative to the previously studied Gd₂(Ti₁–_xZr_x)₂O₇ system. The temperature and composition dependence of the p-type electronic conductivity were evaluated and the oxidation enthalpy was derived.     

氟化氪真空紫外辐射的观察

实验观察到一种新的离子准分子──氟化氪离子准分子产生的真空紫外连续谱辐射，其峰值位于１４８ｎｍ处。实验结果与理论计算值符合很好。     

硅烷修饰SBA-15与固载聚醚离子液体化催化剂的制备与性能

将3种聚醚离子液体,即Cl[PECH-MIM]-OH、Cl [PECH-MIM]-COOH和Cl [PECH-MIM]-NH₂,分别与助催化剂ZnBr₂反应制得复合型聚醚离子液体,再用硅烷(CPTES)修饰分子筛SBA-15,并将其固载复合聚醚离子液体,制得固载化催化剂SCP-OH/[ZnBr₂]、SCP-COOH/[ZnBr₂] 和 SCP-NH2/[ZnBr₂]。利用红外光谱仪、热重分析仪、电镜扫描仪对SBA-15及3种固载化催化剂进行化学结构、热性能和表观形貌的表征,并研究其催化环氧丙烷(PO)与CO₂合成碳酸丙烯酯(PC)反应的性能。结果表明,复合型聚醚离子液体成功固载于硅烷分子筛上,实现了离子液体的相态转变及其高效的非均相转化CO₂。对于3种固载化离子液体催化环氧丙烷与CO₂的羰基化反应SCP-COOH/[ZnBr₂ 的催化性能最佳,在CO₂压力3.0 MPa、反应温度130  ℃、液时空速为0.5 h^-1的反应条件下,PO转化率为83.8%、产物PC选择性为94.1%,并且连续使用80 h后仍保持良好的催化性能。     

Crude Oil Production

Current data on crude oil, field/lease condensate, and natural gas liquids produced from NGL plants. Updated on a monthly basis.     

Crude Oil Production

Current data on crude oil, field/lease condensate, and natural gas liquids produced from NGL plants. Updated on a monthly basis.