Kinetics of Forward Extraction of Boric Acid from Salt Lake Brine by 2-Ethyl-1,3-hexanediol in Toluene Using Single Drop Technique

The kinetics of forward extraction of boric acid from salt lake brine by 2-ethyl-1,3-hexanediol in tolu-ene was investigated using the single drop technique. The factors affecting the extraction rate include interfacial area between aqueous phase and organic phase, initial concentration of boric acid in aqueous phase, initial concen-tration of 2-ethyl-1,3-hexanediol in organic phase, and extraction temperature. The experimental results show that the extraction rate increases with the increase of the initial concentration of boric acid and 2-ethyl-1,3-hexanediol, interfacial area of two phases, and temperature. With the temperature-dependence study, it is showed that the ex-traction is a diffusion-controlled process. The kinetic equation is presented for pH 1.0 in the aqueous phase and temperature of 318 K.     

Synthesis,characterization and electrochemical evaluation of anticorrosion property of a tetrapolymer for carbon steel in strong acid media

A novel tetrapolymer(TP) consisting of carboxylate, sulphonate, phosphonate and sulfur dioxide based comonomers was synthesized using Butler cyclopoymerization technique. The synthesized tetrapolymer was characterized using FTIR,1 H-NMR,~(13)CNMR and elemental analysis. The performance of the tetrapolymer as a corrosion inhibitor for St37 carbon steel in 15% HCl and 15% H_2SO_4 acid media was assessed using electrochemical impedance spectroscopy(EIS), linear polarization resistance(LPR), potentiodynamic polarization(PDP) and electrochemical frequency modulation(EFM) techniques. The influence of addition of a small amount of KI on the corrosion inhibition efficiency of TP was also assessed. Results obtained showed that the tetrapolymer moderately inhibited the corrosion of St37 steel in the acid media with protection efficiency of 79.5% and 61.1% at the optimum concentration of 1000 mg·L~(-1) studied in HCl and H_2SO_4 media respectively. On addition of 5 mmol·L~(-1) KI to the optimum tetrapolymer concentration, the protection efficiency was upgraded to 90.6% and 93.5% in HCl and H_2SO_4 environment, respectively. The enhanced performance of the polymer in the presence of KI is due to synergistic action deduced from synergism parameter(S1) which was found to be greater than unity.The tetrapolymer afforded the corrosion inhibition of St37 steel in the acid media by virtue of adsorption of the polymer molecules on the steel surface which was confirmed by ATR-FTIR analysis of the adsorbed film extracted from the steel surface. TP + KI formed complex with St37 steel surface in H_2SO_4 solution but not in HCl solution.     

Conductivities of AlCl3/Ionic Liquid Systems and Their Application in Electrodeposition of Aluminium

Solubilities and conductivities of anhydrous AlCl3 in six kinds of ionic liquids (ILs) were measured. Among the six kinds of ILs [bmim]Cl, [bmim]Br, [bmim]BF4, [bmim]PF6, [emim][EtSO4] and [bmim][HSO4], anhydrous AlCl3 could be dissolved in the first five kinds but was hardly dissolved in [bmim][HSO4]. The results showed that the nominal solubilities of AlCl3 in ILs increased in the order of [bmim][HSO4] < [bmim]PF6 < [emim][EtSO4] < [bmim]BF4 < [bmim]Cl < [bmim]Br. Conductivities of the AlCl3/ILs systems depended apparently on the nominal molar ratio of AlCl3 to ILs. The conductivities of AlCl3/[bmim]Cl, AlCl3/[bmim]Br and AlCl3/[bmim]PF6 systems had a similar tendency as a function of the nominal molar ratio, that is, as the molar ratio was increased, conductivities increased first and then decreased, with the maximum conductivity obtained at approximately 0.9:1, 1.0:1 and 0.5:1, respectively. Conductivities of the AlCl3/[bmim]BF4 exhibited a dentate change and decreased with the molar ratio of AlCl3 to [bmim]BF4 increasing in general. With the increasing of the anhydrous AlCl3 amount in [emim][EtSO4], conductivity of AlCl3/[emim][EtSO4] monotonically decreased. AlCl3/[bmim]Cl system was chosen as the electrolyte for the electrodeposition of Al. Preliminary experimental results showed that dense, adherent and homogeneous Al coatings could be electrodeposited on stainless steel by means of constant potential technique and the surface coverage was quite satisfactory.     

Enhanced Recovery of Resveratrol and Emodin from Polygonum cuspidatum by a Simultaneous Extraction and Acid Hydrolysis Process

A novel and efficient extraction/hydrolysis method was developed for the recovery of resveratrol and emodin from a well-known traditional chinese medicinal herb, Polygonum cuspidatum. By using a 85% aqueous acetone solution containing 1.0 mol/L HCl as extractant, extraction of resveratrol and emodin from P. cuspidatum and conversion of resveratrol-3-O-β-glucoside and emodin-8-O-β-D-glucoside into the products could be achieved in one step. The effects of several key parameters including concentration of HCl and acetone, temperature, ratio of solvent to material, extraction duration and extraction times on the process efficiency was systematically investigated. The results showed that the optimal conditions for maximizing the recovery yield were 85% acetone containing 1.0 mol/L HCl as extractant, temperature 70 ℃, ratio of liquid to solid 50 mL /g and extraction duration 30 min. This one-pot extraction/hydrolysis process increased the yield of resveratrol and emodin to 524% and 302%, respectively, compared to a raw sample without hydrolysis. Compared with conventional method, the developed process not only achieved high yield of resveratrol and emodin, but simplified the procedures and reduced time. The results demonstrated that the simultaneous extraction/hydrolysis process is simple and efficient which could act as a useful approach for enhanced recovery of resveratrol and emodin from P. cuspidatum.     

Kinetic study on selective extraction of HCl and H3PO4 in a microfluidic device☆

In the extraction method for preparing KH2PO4, one of the key processes is the selective extraction of HCl over H3PO4. In our work, extraction kinetic studies have been carried out in a microfluidic device with a coaxial microchannel, using the extractant of 33.3%(by volume) trioctylamine (TOA) dissolved in n-octanol, with differ-ent aqueous phases:the HCl solution, the H3PO4 solution, and H3PO4 and KCl solutions of different concentra-tions. The changes of the extraction efficiency of HCl and H3PO4 and the selectivity for HCl along with the residence time were investigated. We found that fast extraction kinetics could be realized in microfluidic devices, and that HCl could be extracted faster than H3PO4 due to smaller mass transfer resistance and much stronger re-action between HCl and TOA. For the extraction of H3PO4 and KCl solutions, the selectivity for HCl first increased and then decreased when TOA was in excess of H3PO4 in the initial feeds, and in contrast, always increased when H3PO4 was in excess of TOA in the initial feeds. The diverse changes of selectivity for HCl along with the residence time indicate that a dynamic control of selectivity in microfluidic devices may be important and accessible for im-proving the KH2PO4 conversion efficiency in extraction method.     

Effective and simple recovery of 1,3-propanediol from a fermented medium by liquid–liquid extraction system with ethanol and K_3PO_4

1,3-Propanediol,traditionally obtained from fossils,has numerous industrial applications,including use in the production of high performance polymers.The microbial production of 1,3-propanediol presents several opportunities,and the final purity grade determines its price and commercial viability.The development of novel separation technology could improve the economic viability of the bioproduction of 1,3-propanediol.Thus,we investigated salting-out extraction as a novel process for 1,3-propanediol recovery from fermentation broth.Initially,a screening for the best salt/solvent combination was conducted and then optimized using the response surface methodology.The solvents studied were methanol,ethanol,isopropanol and acetone,and the salts examined were K_2HPO_4,Na_2CO_3,K_2CO_3,(NH_4)_2SO_4,NaHPO_4,K_3PO_4 and C_6H_5NaO_7.The optimal extraction system consisted of 34 wt%K_3PO_4,28 wt% ethanol,and 38 wt% fermentation broth containing 23.0 g·L~(-1)1,3-propanediol,which gave the highest partition coefficient of 33 and recovery yield of 97%.The results demonstrated that salting-out extraction was a promising method for 1,3-propanediol recovery from fermentation broth.     

介孔分子筛Al-MCM-41接枝三丁基氯化锡的表征及催化性能(英文)

Surface organometallic chemistry (SOMC) is a recently developing research field. It is of great significance for the quantitative modification, restoration of solid surface, identification of the physical and chemical nature of surface and the preparation of new catalyst. The production of R 3 Sn-O-MCM-41 (R 3 SnM) was obtained by heating tributyltin chloride and Al-MCM-41 mixture at 170 °C for 5 h under stirring in nitrogen atmosphere. The composition, structure and surface physical and chemical properties of the samples were characterized by inductively coupled plasma mass spectrometry (ICP-MS), 13 C, 119 Sn, 29 Si and 27 Al solid state NMR (nuclear magnetic resonance) spectra, in-situ pyridine infrared spectroscopy (Py-IR), N 2 adsorption-desorption, X-ray diffraction (XRD), transmission electron microscopy (TEM), etc. The results of ICP and organic elemental analysis shows that the grafting yield w Sn was 6.46% for R 3 SnM. H 0 (the negative logarithm of the acid concentration)and the number of acid sites for R 3 SnM respectively were 2.77-0.99 and 4.8 mmol·g-1 by the Hammett method. N 2 adsorption-desorption, XRD, TEM analysis showed that R 3 SnM with ordered hexagonal mesopore structure, resulted in the decease of surface areas and pore size as well as the increase of mesoporous volume and surface acidity, as compared to Al-MCM-41. R 3 SnM was used in the synthesis of isoamyl acetate. The yield of isoamyl acetate was 96% when n(isoamyl alcohol)︰n(acetic acid) 1.0︰1.0, 3 R SnM w 5%, 138 °C for 5 h. The catalyst can be reused and the yield of 86% can be attained when catalyst was reused five times at the same catalytic conditions.     

Effects of Precursors for Preparing Intermediate Layer on the Performance of Ti/SnO2+Sb2O3/PbO2 Anode

The Ti/SnO2+Sb2O3/PbO2 anode with SnO2+Sb2O3 intermediate layer obtained by the polymeric precursor method (PPM) and with the conventional route was studied. The morphology and microstructure of SnO2+Sb2O3 intermediate layer derived from different precursors and the top PbO2 active layer were examined by means of ESEM and XRD. The lifetime and electrocatalytic activity of the anode were also assessed by the cyclic voltammetry and accelerated lifetime test in 1.0 mol/L H2SO4 solution. It was found that precursor solvents affected lifetime, microstructure and morphology of the anode, and had little influence on electrocatalysis activity of the electrodes. The accelerated lifetime of Ti/SnO2+Sb2O3/PbO2 anode with intermediate layer prepared by PPM was 29.5 h in 1.0 mol/L H2SO4 solution, which was respectively about four times and twice that of the anode prepared with ethylene glycol and ethanol. After the anode was subjected to thermal corrosion, the lifetime still reached 27 h in contrast to the others.     

Modification and sequential treatment of EU-1 zeolite in mild alkali and alkaline-acid conditions

EU-1 zeolites were sequentially treated with low-concentration sodium carbonate(Na_2CO_3) and hydrochloric acid(HCl) solutions.The obtained samples were characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),N_2 adsorption/desorption,temperature programmed desorption of NH_3(NH_3-TPD),solid state~(27)A1 nuclear magnetic resonance(~(27)A1 NMR),and the catalytic performances of the treated samples were tested in the xylene isomerization reaction.The results showed that the external surface area and mesoporous volume of the sample sequentially treated with 0.05 mol·L~(-1) Na_2CO_3 and 0.1 mol·L~(-1) HCl solutions reached73.9 m~2·g~(-1) and 0.162 cm~3·g~(-1),respectively.The catalytic performances of EU-1 zeolites were significantly improved,that the activity of the probe reaction increased from 23.03%to 23.61%and the selectivity increased from85.09%to 87.14%compared with those of parent sample.Furthermore,it was found that only amorphous silica and alumina species was dissolved during the post-treatment process,but the framework structure and the acidic properties of EU-1 zeolite remained intact.     

采用极性及非极性溶剂从酸洗后的红法夫酵母中高效萃提虾青素的研究(英文)

method of extracting astaxanthin from Phaffia rhodozyma with various solvents after acid washing was investigated.The extraction efficiency was distinctly increased after acid washing of P.rhodozyma cells.When the concentration of HCl was 0.4 mol·L-1,the highest extraction efficiency of astaxanthin was achieved which was about three times higher than the control.Acetone or benzene as single polar or non-polar solvent was the most effective solvent in our research.With a combination of isopropanol and n-hexane(volume ratio of 2:1),the maximal extraction efficiency was achieved,approximately 60% higher than that obtained with a single solvent.The liquid-solid ratio and the extracting time were also optimized.Under the optimum extraction conditions,the extraction yield of astaxanthin exceeded 98%.     

TNAZ中间体(Ⅱ)的合成及表征

以3-叔丁基-5-羟甲基-5-硝基四氢-l,3-噁嗪为原料,以水为溶剂,经酸性水解合成了TNAZ中间体(Ⅱ)2-叔丁氨甲基-2-硝基-l,3-丙二醇盐酸盐,并通过红外光谱、核磁共振和元素分析对其结构进行了表征。讨论了溶剂种类、水用量、盐酸用量、温度和时间对收率的影响。确定了最佳合成工艺条件为:当n(3-叔丁基-5-羟甲基-5-硝基四氢-l,3-噁嗪)∶n(HCl)∶n(H2O)=1∶3.6∶20,控温35~45℃反应9h、55~60℃反应11h,产物纯度为98%,收率为95%。     

一锅法合成2,4-二氟苯乙腈

研究了以2,4-二氟苯甲醛为起始原料,以水为溶剂经硼氢化钾还原,带水剂的作用下进行氯化和氰化反应一锅法合成2,4-二氟苯乙腈。考察了不同还原剂和带水剂对反应收率及产品质量的影响。结果表明,适宜的工艺条件为:2,4-二氟苯甲醛∶硼氢化钾∶氯化亚砜∶氰化钠=1∶0.36∶1.26∶1.35,用甲苯作为带水剂及氯化反应和氰化反应的溶剂,氰化反应的温度为90℃,反应时间3 h,总收率可达62.1%。该过程具有操作简单、适合工业化生产的特点。     

1,3∶2,4-二（3,4-二甲基苯亚甲基）山梨醇的制备工艺优化

通过正交实验优化了聚烯烃成核剂HX-3主要成分1,3∶2,4-二（3,4-二甲基苯亚甲基）山梨醇（DMDBS）的制备工艺。在以环己烷（400 mL）和甲醇（60 mL）为溶剂、对甲基苯磺酸（1.0 g）为催化剂、山梨醇（0.15 mol）与3,4-二甲基苯甲醛（0.30 mol）回流反应6 h的优化条件下,DMDBS平均收率达98.9%、熔点≥254.3℃、纯度≥98.17%。在5 L搪玻璃釜中进行23次放大实验,验证了优化工艺,并已在工业化规模生产中成功应用。     

SiO2键合PEG钼(Ⅵ)配合物合成、表征及对环己烯环氧化催化活性

合成了SiO₂键合聚乙二醇（PEG）高分子配体,将钼（Ⅵ）合乙酰丙酮组装在该高分子配体上合成出SiO₂负载PEG钼（Ⅵ）配合物,并用元素分析、红外光谱以及X射线光电子能谱技术对其进行了结构表征.建立了SiO₂键合PEG钼（Ⅵ）配合物催化剂中Mo的化学分析新方法.实验表明：该配合物作为环己烯环氧化用催化剂,具有优良的催化活性和选择性.在叔丁基过氧化氢为0.1 mol、环己烯与叔丁基过氧化氢摩尔比为3.5∶1、溶剂10 ml、反应温度80 ℃、时间60 min条件下,环氧环己烷收率（以叔丁基过氧化氢计）在99.2%以上,质量分数≥99.5%（GC检测）.     

对氟苯甲醛的合成

以氟苯和CO为原料,AlCl3和无水HCl为催化剂,在1 0～3 5MPa的CO压力下反应合成了对氟苯甲醛。考察了各因素对转化率和收率的影响。得出最佳工艺条件为:n(氟苯)/n(AlCl3)=1 0,反应温度70℃,HCl用量为反应物料总质量的1 0%,反应时间为1 5h。在此工艺条件下,氟苯转化为对氟苯甲醛的选择性可达99 1%,产率为95%以上,精制后产品纯度w(对氟苯甲醛)>99%。     

TDI扩链端羟基聚乳酸的研究

以1,4-丁二醇和乳酸在辛酸亚锡催化下,进行熔融缩聚反应,形成端羟基聚乳酸,再以2,4-甲苯二异氰酸酯(TDI)进行扩链反应,合成可溶性聚酯型聚氨酯共聚物。用粘均相对分子质量、红外光谱、XRD对产物进行表征。结果表明,在nNCO∶nOH=1.0∶1.0、170℃和0.096 MPa条件下反应30 min,可得到粘均相对分子质量为13.2万的扩链产物,为扩链前端羟基聚乳酸的6.3倍;XRD测试表明,扩链使结晶度由扩链前27.95%下降到扩链后6.94%。     

2,2-二羟甲基丁醛的催化合成与表征

采用新制的正丁醛（NBAL）和多聚甲醛（PFA）在三乙胺（TEA）催化下制备了合成三羟甲基丙烷（TMP）的中间产物2,2-二羟甲基丁醛（DMB）.探讨了原料配比和反应时间对DMB收率的影响,以及催化剂与含水量对反应体系升温速率及DMB收率的影响.最佳工艺条件为：N₂保护下,n_NBAL∶n_PFA∶n_TEA为1∶3∶（0.05～0.1）,含水量为10％～15％（以总量计）,反应温度为50～80℃,反应时间为2h.通过IR、GC、GC-MS、¹HNMR对DMB的结构进行了表征;经过GC分析,NBAL在上述条件下可反应完全（＞99％）,DMB收率达88％以上.     

TiO_2负载磷钨杂多酸催化剂催化合成缩醛(酮)

以TiO2负载磷钨杂多酸(H3PW12O40/TiO2)为催化剂,对以乙酰乙酸乙酯、环己酮、丁酮、苯甲醛和正丁醛与二元醇(乙二醇,1,2-丙二醇)为原料合成2-甲基-2-乙氧羰甲基-1,3-二氧环戊烷、2,4-二甲基-2-乙氧羰甲基-1,3-二氧环戊烷、环己酮乙二醇缩酮、环己酮1,2-丙二醇缩酮、丁酮乙二醇缩酮、丁酮1,2-丙二醇缩酮、2-苯基-1,3-二氧环戊烷、4-甲基-2-苯基-1,3-二氧环戊烷、2-丙基-1,3-二氧环戊烷、4-甲基-2-丙基-1,3-二氧环戊烷10个缩醛(酮)的反应条件进行了研究。较系统地研究了醛或酮与二元醇摩尔比、催化剂用量、反应时间诸因素对收率的影响。结果表明,在n(醛或酮)∶n(乙二醇或1,2-丙二醇)=1∶1.5,催化剂的用量占反应物料总质量的1.25%,反应时间为1 h条件下,10种缩醛(酮)的收率为45.2%~92.2%。     

改性活性炭催化合成苯乙酮1,3-丙二醇缩酮工艺研究

采用活性炭负载Al2(SO4)3作为催化剂(Al2(SO4)3改性活性炭);以苯乙酮和1,3-丙二醇为原料合成苯乙酮1,3-丙二醇缩酮.考察了Al2(SO4)3。改性活性炭催化剂用量、原料配比、回流时间和带水剂用量对此反应工艺条件的影响.最佳的反应工艺条件为Al2(SO4)3改性活性炭用量为苯乙酮用量的6.67%,n(苯乙酮)∶n(1,3-丙二醇)=1∶1.1,带水剂用量为15 mL,回流时间为5 h,在此最佳反应条件下苯乙酮1,3-丙二醇缩酮的收率为61.15%,经前馏分循环使用可使收率提高到65.64%,产品的纯度为98.1%。Al2(SO4)3。改性活性炭催化剂的制备简单,催化活性好,而且重复利用后的产率并不下降,其后处理简便,无三废污染,符合环保、绿色催化的发展的趋势。     

4-氯-2,5二氟苯甲酸的合成

提出了一种以2,5-二氟苯胺为原料,经Sandmeyer反应、溴化和格氏反应三步得到4-氟-2,5-二氟苯甲酸的合成方法.其中溴化反应的最佳反应条件为:n(2-氯1,4-二氟苯):,你、n(溴素)=1:1.13,n(2-氯1,4-二氟苯):n(无水三氯化铁)=1:0.03,溴化反应温度为30℃,反应时间为5h.三步总摩...