TPB3 TSi黄光OLED材料的制备及其性能优化

制备以TPB3TSi为发光材料的黄色发光器件。实验表明,当TPB3TSi薄膜厚度为20nm时,器件的发光谱峰位于580nm,其双层和3层器件的最大亮度分别达到7507.6和1385cd/m2(17V电压下),但是器件的电流较大,造成了器件的发光效率偏低,其原因是TPB3TSi材料本身的电荷陷阱(所谓陷阱指的是拥有比母体更容易接受电子或者空穴的能级的位置)较多,荧光效率低,从而降低了器件的效率。

Simulation of 1,3-Butadiene Production Process by Dimethylfomamide Extractive Distillation

Nowadays, extractive distillation is the main technique to produce 1,3-butadiene. This study simulated the 1,3-butadiene production process with DMF extractive distillation by Aspen Plus. The solvent ratio is the most important parameter to the extractive distillation process. The article has given out the proper solvent ratios, reflux ratios, distillate ratios, and bottom product ratios of the columns. It also discusses the thermal loads of several columns. The results of simulation are consequently compared with the plant data, which shows good accordance with each other.

Coupling effect of bifunctional ZnCe@SBA-15 catalyst in 1,3-butadiene production from bioethanol

A series of bifunctional Zn Ce@SBA-15 catalysts with different Zn/Ce ratios were prepared by a solid-state grinding strategy and used in the conversion of ethanol to 1,3-butadiene(ETB).For the supported metal oxides,Zn O serves as the active sites for the dehydrogenation of ethanol,and CeO_(2) promotes the aldolcondensation reaction.Based on the results of Py-FTIR and NH_(3)-TPD,it suggests that the yield of 1,3-butadiene is positively correlated with the number of weak Lewis acid sites on the catalyst surface,given their benefit for aldol-condensation reactions.The catalyst with an optimal Zn/Ce ratio of about 1:5 has the highest concentration of weak Lewis acid.Coupling with the Zn O sites,it contributes to a 98.4%conversion of ethanol and a 45.2%selective of 1,3-butadiene under relatively mild reaction conditions(375°C,101.325 k Pa,and 0.54 h^(-1)).

Selective hydrogenation of 1,3-butadiene on iridium nanostructures:Structure sensitivity, host effect, and deactivation mechanism

A systematic study on the structure sensitivity,host effect,and the deactivation mechanism of Ircatalyzed selective hydrogenation of 1,3-butadiene,a key process in the purification of alkadiene for the upgrading of C4 cut,is presented by coupling steady-state catalytic testing,in-depth characterization,kinetic evaluation,and density functional theory calculations.We reveal that:(i) 1,3-Butadiene hydrogenation on iridium is structure-sensitive with the optimal particle size of about 2 nm,and the H_(2) dissociation energy is a reliable activity descriptor;(ii) The nature of the NC hosts exerts a critical impact on the catalytic performance,and balanced nitrogen content and speciation seem key for the optimized performance;and (iii) Different deactivation mechanisms occur:fouling by coke deposition on the catalysts with a high N:C ratio (>1),and site blockage due to the competitive adsorption between 1-butene/cis-2-butene and 1,3-butadiene.These molecular insights provide valuable guidelines for the catalyst design in selective hydrogenations.

In Situ IR Spectroscopic Study on the Hydrogenation of 1,3-Butadiene on Fresh Mo_2C/γ-Al_2O_3 Catalyst

The surface species formed from the adsorption of 1,3-butadiene and 1,3-butadiene hydrogenation over the fresh Mo2C/γ-Al2O3 catalyst was studied by in situ IR spectroscopy. It is found that 1,3-butadiene adsorption on the Mo2C/γ-Al2O3 catalyst mainly forms π-adsorbed butadiene(πs and πd) and σ-bonded surface species. These species are adsorbed mainly on the surface Moδ+(0<δ<2) sites as evidenced by co-adsorption of 1,3-butadiene and CO on the fresh Mo2C/γ-Al2O3 catalyst. The IR spectrometric analysis show that hydrogenation of 1,3-butadiene over fresh Mo2C/γ-Al2O3 catalyst produces mainly butane coupled with a small portion of butene. The selectivity of butene during the hydrogenation of 1,3-butadiene over fresh Mo2C/γ-Al2O3 catalyst might be explained by the adsorption mode of adsorbed 1,3-butadiene. Additionally, the active sites of the fresh Mo2C/γ-Al2O3 catalyst may be covered by coke during the hydrogenation reaction of 1,3-butadiene. The treatment with hydrogen at 673 K cannot remove the coke deposits from the surface of the Mo2C/γ-Al2O3 catalyst.

Azo-coupling Decarboxylation Reaction of α-Carboxy Ketene Dithioacetals in Water-a New Route to 1,2-Diaza-1,3-butadienes

Under basic conditions, a series of 4,4-dialkylthio-l,2-diaza-l,3-butadienes were synthesized in good to excellent yields via a novel azo-coupling decarboxylation reaction by reacting a-carboxyl ketene dithioacetals with aryldiazonium salts in aqueous medium.

碳酸氢铵中氮含量的示波滴定法

研究了NH4 HCO3氮含量的示波滴定法。用过量四苯硼钠沉淀铵 ,沉淀过滤 ,过量的四苯硼钠用氯化四乙基铵标准溶液返滴定 ,以四苯硼钠切口消失为终点 ,计算出氮含量。本方法终点变化敏锐 ,不外加指示剂 ,与通用的标准分析方法相比较 ,操作简便、快速 ,测定结果准确可靠 。

Predicting of Covalent Organic Frameworks for Membrane-based Isobutene/1,3-Butadiene Separation:Combining Molecular Simulation and Machine Learning

Efficient separation of C4 olefins is of critical importance and a challenging task in petrochemical industry. Covalent organic frameworks(COFs) could be used as promising candidates for membrane-based isobutene/1,3-butadiene(i-C4H8/C4H6) separation. Owing to large amounts of COFs appearing, however, the rapid prediction of optimal COFs is imperative before experimental efforts. In this work, we combine molecular simulation and machine learning to study COF membranes for efficient isolation of i-C4H8 over C4H6. Using molecular simulation, four potential COF membranes, which possess both high membrane performance score (MPS) value and moderate membrane selectivity were screened out and the mechanism of membrane separation further revealed is an adsorption dominated process. Further, random forest(RF) model with high prediction accuracy(R2>0.84) was obtained and used for elucidating key factors in controlling the membrane selectivity and i-C4H8 permeability. Ultimately, the optimal COF features were obtained through structure-performance relationship study. Our results may trigger experimental efforts to accelerate the design of novel COFs with better i-C4H8/C4H6separation performance.

Conformational sensitivity of tetraphenyl-1,3-butadiene derivatives with aggregation-induced emission characteristics

Organic dyes with conformational sensitivity can be used to probe weak interactions at the molecular level.Here,three molecules based on tetraphenyl-1,3-butadienes(TPBs)were synthesized and studied with respect to their synthesis,structural characterization and potential application.All TPBs showed aggregation-induced emission(AIE)characteristics and sensitive conformational properties,in which the emission wavelengths could be changed in different states.The TPBs single crystals revealed that the phenyl groups at the 4-position of the 1,3-butadienes contributed to their conformational sensitivity.Furthermore,the potential application for monitoring the interactions among polyelectrolyte complexes and metal ions was explored,and the results showed that TPBs could be used for sensitively probing some weak interactions by changing the emission wavelengths due to their conformation-sensitive properties.TPBs may become a new star in AIE research fields.

AM1 computational study on metabolites of l ,3-butadiene interstrand cross-linking DNA

The alkylating reactions of 1,2-epoxy-3,4-butene (EB) and 1,2,3,4-diepoxybutane (DEB)-the important metabolites of rodent carcinogenic 1,3-butadiene, with adenine and cytosine andinteraction with fragment of DNA on major groove-have been computed. Results show thatthere are little differences in activation energy between EB and DEB, so it is difficult to explain the fact that the mutagenicity of DEB is greater (about 100-fold) than that of EB by the ability of alkylation. it is also known that DEB can interstrand cross-link with DNA through two times alkylating reactions, whereas EB cannot. So this may contribute to the significant different genotoxicity of the two agents. Meanwhile, DEB can interstrand cross-link with many sequences of DNA in major groove vs. two in minor groove, which increases opportunity of interstrand cross-link with DNA in major groove. This difference may be the reason of base selection of DEB mutation. The deformation of some cross-linked DNA may also contribute to this

Analysis of Operating Variables in the Catalytic Purification of Butene-1 in a Trickle Bed

A mathematical model for analyzing and simulating selective hydrogenation of butyne-1 and 1,3-bu-tadiene in industrial trickle bed reactors operated to obtain high purity butene-1 is presented in this work.Fromthe analysis of typical operating conditions,only the relevant phenomena are finally retained in the model formu-lation.The model is then employed to analyze the effect of operating variables and catalyst selectivity in processperformance.In particular,the search for the minimum hydrogen flow rate necessary to fulfil butene-1 purityspecifications is undertaken.

Approximate Expressions to Evaluate the Performance in Butene-1 Purification Units

1 INTRODUCTIONSelective hydrogenatioll of small amounts of butynes and butadiene is industrially employedfor obtaining high purity butene-l used as co-monomer in the production of linear low-densitypolyethyene.For this purpose,the content of vinylacetylene.butyne-l and 1,3-butadiene presentin the process stream should be reduced to a few tens of ppm.

Theoretical calculation of rate constants for the thermal isomerization from 1,2-butadiene to 1,3-butadiene

Ab initio electronic structure calculations at 6-31G** level were performed to determine the mechanism of the isomerization reaction from 1, 2-butadiene to 1, 3-butadiene. The MP2 method was used to improve the barrier energies of the reaction. The calculation results show that the reaction is a stepwise process via a radical INT; the barrier energies determined forTS1 and TS2 at UMP2/6-31G**//UHF/6-31G**+ZPE level are 64.95×4.184 and 64.10×4.184 kJ/mol, respectively. Based on the unified statistical theory, the thermal rate constants for the present complex reaction mechanism were computed over the termperature range 1100–1600 K. The computed thermal rate constants for the reaction are well represented by the following Arrhenius expression:k(T) = 2.4×1013 exp (- 62.8 kJ/RT) s-l. The theoretical investigations are found to be in quantitative agreement with the experimental results.

Kinetic model of gas phase polymerization of 1,3-butadiene catalyzed by supported rare earth coordination system

Gas phase polymerization of 1,3-butadiene (Bd) catalyzed by supported rare earth coordination system is studied and a new kinetic model is proposed. Four elementary reactions or processes: the process of exposure and activation of potential active catalytic center, propagation, deactivation and chain transfer reaction to alkyl aluminum, are considered in this model. Some important parameters, such as monomer-consuming rate, are well expressed as the functions of macroscopic polymerization conditions such as pressure, temperature, and duration. The model can simulate the whole polymerization procedure satisfactorily.

Hydroxyl Group-Enabled Highly Efficient Ligand for Pd-Catalyzed Telomerization of 1,3-Butadiene with CO_(2)

By introducing hydroxyl group into PPh3 ligand,a promoter-free palladium catalytic system based on(p-HOC6H4)PPh2 ligand was developed for the telomerization of 1,3-butadiene with CO_(2).High activity and selectivity towards CO_(2)-incorporated divinylδ-lactone monomer were achieved(TON/TOF:up to 4540/568 h–1;selectivity ofδ-lactone and its isomers:up to 97%).The key role of phenolic hydroxyl group of the ligand in attaining high activity was validated.The good performance of large-scale reaction in batch reactor demonstrated the potential utility of this simple catalytic system in valorizing CO_(2) with bulk chemical feedstock.

Synthesis of 5-vinyl-2-norbornene through Diels-Alder reaction of cyclopentadiene with 1,3-butadiene in supercritical carbon dioxide

An efficient method for the synthesis of 5-vinyl-2-norbornene from cyclopentadiene and 1,3-butadiene was developed.The Diels-Alder reaction of cyclopentadiene with 1,3-butadiene proceeded smoothly in supercritical carbon dioxide in the absence of any polymerization inhibitor to produce the corresponding5-vinyl-2-norbornene in satisfactory yield with high selectivity.

Respiratory Symptoms and Spirometry Profile of Plastic Factory Workers in Ogun State, Southwest Nigeria

Background: Exposure to plastic fumes can lead to severe occupational hazards due to inhalation, ingestion or direct contact wide variety of potentially harmful by-products during the manufacturing and burning of plastics. Objectives: To determine the prevalence of respiratory symptoms in plastic factory workers, evaluate the respiratory function of plastic factory workers and the association between respiratory symptoms and the duration of employment. Methods: This was a cross-sectional study done among plastic factory workers. Using a random sampling technique, 190 individuals (95 subjects and 95 control) above 18 years of age were recruited. Data were obtained with a validated questionnaire and Spirometry was done. Result: The mean age of the study group and control were 30.27 ± 7.38 and 25.92 ± 4.63 respectively (t = 4.877;p Conclusion: Workplace exposure to plastic fumes can lead to development of respiratory symptoms and impaired pulmonary function.

3D reconstruction size effect on the quantification of solid oxide fuel cell nickel-yttria-stabilized-zirconia anode microstructural information using scanning electron microscopy-focused ion beam technique

Self-made conventional nickel-yttria-stabilized zirconia composite anodes after reduction and 500 h operation were analyzed by three-dimensional microstructure reconstruction based on focused ion beam-scanning electron microscopy technique.Interfacial area,threephases-boundary density and phase volume fraction were measured based on the three-dimensional microstructure reconstruction to quantitatively study the statistical characterization of solid oxide fuel cell nickel-yttria-stabilizedzirconia anode microstructure before and after operation.It is found that for anode operated with long time,it is necessary to increase the corresponding three-dimensional reconstruction size to suppress the influence of microstructure variation caused by Ni agglomeration in order to obtain more accurate microstructural quantification information.

Efficient Synthesis of Triarylamines Catalyzed by Copper(I)Diazabutadiene Complexes

Cuprous chloride was coordinated by diazabutadiene(DAB-R)ligands to form Cu(I)-(DAB-R)complexes,most of which have a 1∶1 ratio of Cu to DAB-R as reported.In the case of a special DAB-iPP,N,N'-bis(2,6-diiso-propylphenyl)-1,4-diaza-1,3-butadiene,an unexpected composition of complex was found with the formula Cu(I)Cl(DAB)_(2).When employed as catalyst for triarylamine synthesis from the coupling of aryl halides with pri-mary and secondary arylamines,the new Cu(I)-(DAB-iPP)complex displayed high efficiency.