Probing the electronic environment of binary and ternary ionic liquid mixtures by x-ray photoelectron spectroscopy

X-ray photoelectron spectroscopy is used to probe the electronic environment of cations and anions for three binary and one ternary chlorostannate ionic liquid mixtures. The impact of the weighting of Cl on the electronic environment of the cation-based nitrogen atom is revealed in detail. With the increasing of the concentration of Cl , the N 1s binding energy is decreased. The electronic environment of the anion- based component is also compared based upon Sn 3d5/2 and Cl 2p3/2 binding energies. It is found that with the increasing of the weighting of Cl , binding energies of Sn 3d5/2 and Cl 2p3/2 both decrease

Tuning the electronic environment of the anion by using binary ionic liquid mixtures

The electronic environment of the anion is tuned by using binary ionic liquid mixtures employing a com- mon anion and two cations with large difference in acidity. X-ray photoelectron spectroscopy is used to monitor the change of the electronic environment of the anion by measuring the binding energy of elements present in the anion. It is found that due to the large difference in acidity of the two cations, noticeable shifts can be observed for all anion-based components, no matter how basic the anion is

Spectroscopic analysis of 1-butyl-2,3-dimethylimidazolium ionic liquids: cation-anion interactions

In this study, four 1-butyl-2,3-dimethylimidazolium ionic liquids are analysed by X-ray photoelectron spectroscopy, together with three 1-butyl-3-methylimidazolium ionic liquids. A reliable fitting model for the carbon 1s region of 1-butyl-2,3-dimethylimidazolium ionic liquids is modified according to estab- lished models. The effect of the anion on the electronic environment of the cation is explored based upon the comparison between measured binding energies of nitrogen 1s and the hydrogen bond acceptor abil- ity. The effect of the cation on the cation-anion interaction is also demonstrated by carefully comparing the hydrogen bond donating ability of different cations, with a definite anion

Tuning the Cation-Anion Interactions by Methylation of the Pyridinium Cation: An X-ray Photoelectron Spectroscopy Study of Picolinium Ionic Liquids

X-ray photoelectron spectroscopy is used to investigate the impact of methylation on the electronic environment of pyridinium cations. Because of the electron-donating effect of the methyl group, there is a significant increase in electron density on the cationic nitrogen. The shift of the N 1s binding energy is inversely proportional to the anion basicity. The methylation position on the electronic environment of the cationic nitrogen is investigated. The N 1s binding energy follows the trend: 1-octylpyridinium > 1-octyl-3-picolinium > 1-octyl-4-picolinium > 1-octyl-2-picolinium, which is in good agreement with the cation acidity. The increase in the inductive effect subsequently weakens the cation-anion interactions through charge transfer from the anion to the cation, causing a subtle change in the electronic environment of the anion. Such an effect is noticeably reflected in the Br 3d binding energy. It shows that the Br 3d5/2 binding energy of 1-octyl-2-picolinium bromide is 0.2 eV lower than that of 1-octylpyridinium bromide

Vanishing of the anomalous Hall effect and enhanced carrier mobility in the spin-gapless ferromagnetic Mn2CoGa1-xAlx alloys

Spin gapless semiconductor (SGS) has attracted long attention since its theoretical prediction, while concrete experimental hints are still lack in the relevant Heusler alloys. Here in this work, by preparing the series alloys of Mn2CoGa1-xAlx (x=0, 0.25, 0.5, 0.75 and 1), we identified the vanishing of anomalous Hall effect in the ferromagnetic Mn2CoGa (or x=0.25) alloy in a wide temperature interval, accompanying with growing contribution from the ordinary Hall effect. As a result, comparatively low carrier density (1020 cm-3) and high carrier mobility (150 cm2/Vs) are obtained in Mn2CoGa (or x=0.25) alloy in the temperature range of 10-200K. These also lead to a large dip in the related magnetoresistance at low fields. While in high Al content, despite the magnetization behavior is not altered significantly, the Hall resistivity is instead dominated by the anomalous one, just analogous to that widely reported in Mn2CoAl. The distinct electrical transport behavior of x=0 and x=0.75 (or 1) is presently understood by their possible different scattering mechanism of the anomalous Hall effect due to the differences in atomic order and conductivity. Our work can expand the existing understanding of the SGS properties and offer a better SGS candidate with higher carrier mobility that can facilitate the application in the spin-injected related devices

X-ray photoelectron spectroscopy of piperidinium ionic liquids: a comparison to the charge delocalised pyridinium analogues

In this study, nine piperidinium-based ionic liquids are analysed by X-ray photoelectron spectroscopy. The effect of alkyl substituent length and the nature of the anion on the electronic environment of the cation are investigated. The electronic environment of the hetero carbon and the cationic nitrogen is compared between two structurally similar cations, 1-octyl-1-methylpiperidinium ([C8C1Pip]+) versus 1-octylpyridinium ([C8Py]+). Due to the charge delocalisation, the hetero carbon component within [C8Py]+ is more positively charged, which exhibits much higher binding energy; whilst the cationic nitrogen component is in the similar electronic environment. The impact of the charge delocalisation on the electronic environment of the anion is also compared between [C8C1Pip]+ and [C8Py]+. It is found that for the more basic anion, the cation can significantly affect the electronic environment of the anion; for the less basic anion, such an effect concentrates on the component bearing more negative point charges

Gene therapy for C-26 colon cancer using heparin-polyethyleneimine nanoparticle-mediated survivin T34A

Ling Zhang1,*, Xiang Gao1,2,*, Ke Men1, BiLan Wang1, Shuang Zhang1, Jinfeng Qiu1, Meijuan Huang1, MaLing Gou1, Ning Huang2, ZhiYong Qian1, Xia Zhao1, YuQuan Wei11State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, 2Department of Pathophysiology, College of Preclinical and Forensic Medical Sciences, Sichuan University, Chengdu, People’s Republic of China*These authors contributed equally to this workBackground: Gene therapy provides a novel method for the prevention and treatment of cancer, but the clinical application of gene therapy is restricted, mainly because of the absence of an efficient and safe gene delivery system. Recently, we developed a novel nonviral gene carrier, ie, heparin-polyethyleneimine (HPEI) nanoparticles for this purpose.Methods and results: HPEI nanoparticles were used to deliver plasmid-expressing mouse survivin-T34A (ms-T34A) to treat C-26 carcinoma in vitro and in vivo. According to the in vitro studies, HPEI nanoparticles could efficiently transfect the pGFP report gene into C-26 cells, with a transfection efficiency of 30.5% ± 2%. Moreover, HPEI nanoparticle-mediated ms-T34A could efficiently inhibit the proliferation of C-26 cells by induction of apoptosis in vitro. Based on the in vivo studies, HPEI nanoparticles could transfect the Lac-Z report gene into C-26 cells in vivo. Intratumoral injection of HPEI nanoparticle-mediated ms-T34A significantly inhibited growth of subcutaneous C-26 carcinoma in vivo by induction of apoptosis and inhibition of angiogenesis.Conclusion: This research suggests that HPEI nanoparticle-mediated ms-T34A may have a promising role in C-26 colon carcinoma therapy.Keywords: gene therapy, mouse survivin-T34A, colon cancer, polyethyleneimine, nanoparticles, cancer therap

X-ray photoelectron spectroscopy of ionic liquid-based catalytic systems

The negligible volatility of ionic liquids allows them to be studied by applying ultrahigh vacuum (UHV) techniques, i.e. X-ray photoelectron spectroscopy (XPS). Consequently, this Thesis describes the XPS of ionic liquid-based metal catalytic systems. Correlation between the binding energy derived from XPS and reaction performance is extensively discussed and used to design a catalytic system for the Suzuki cross coupling reaction. To allow comparable information for the solute dissolved in ionic liquids to be obtained, pure ionic liquids and ionic liquid mixtures are analysed. Fitting models of C 1 s spectra for different ionic liquid families are presented. Charge correction methods, specifically the influence of anion basicity on charge correction, are discussed in detail. The cation-anion interaction is investigated for different families of ionic liquids with single and mixed anions. The interaction between catalysts and ionic liquids can also be demonstrated by XPS. The formation of palladium-containing ylidene complexes in ionic liquids is confirmed by XPS and ESI-MS. The influence of anion basicity on the measured binding energy of the palladium centre is explored. The binding energies of Pd 3d for a range of solutions are plotted against several established metrics, i.e. proton affinity, interaction energy and hydrogen bond acceptor ability (P), and are used to reflect the reaction rates for a model Suzuki reaction. After a proper understanding of the correlation between the binding energy of a metal centre and the reaction rate, a palladium-based catalytic system may be optimised for the Suzuki reaction. The reaction rates observed in ionic liquids with differing basicity anions are monitored and correlated back to the binding energy. XPS is also applied to investigate the interaction of catalysts with ligands in ionic liquid-based rhodium systems. The formation of different rhodium ligand-containing complexes is detected by XPS. The influence of anion basicity on the formation of different rhodium-containing complex is discussed. The measured binding energy of the rhodium centre is correlated to the reaction selectivity in the hydroformylation reaction.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

[[alternative]]Formaldehyde in Indoor Leisure Environment —Measurements at KTV

[[abstract]]論文摘要 據世界衛生組織統計，人們約80~90%的時間在室內活動。而研究顯示室內空氣污染嚴重，其中常見的甲醛會危害健康，已確定為人類致癌物(Group 1 : carcinogenic to humans)。KTV為華人特有之室內休閒活動，其為密閉空間，依法需使用防焰建材，常使用尿素泡沫甲醛樹脂來隔熱絕緣、隔間多、高度裝潢及包廂內常見吸煙行為，故推測其甲醛濃度可能偏高。因此本研究目的在分析KTV包廂中甲醛之潛在暴露途徑，利用直讀式甲醛偵測器實地測量KTV包廂中甲醛濃度，並以實測結果推估可能慢性健康影響，同時進一步探討甲醛去除方法。從文獻探討推估KTV內甲醛之潛在暴露途徑為甲醛由防火建材、室內裝修等固定逸散源及香菸燃燒之移動逸散源，逸散至空氣中經呼吸道被人體吸收。於7家KTV包廂8次實測的結果，30分鐘平均值最大值為0.14ppm、最小值為0.03ppm，平均為0.09ppm，另外五次在包廂中有香菸燃燒的測量結果，香煙未燃燒前的平均值為0.03ppm，香菸燃燒時的30分鐘平均值最大值為0.16ppm，最小值為0.09ppm，平均為0.12ppm。而以實測結果所評估的可能慢性健康影響方面，非致癌慢性健康危害指數皆大於1，消費者之終生致癌風險最小值0.40×10-7，最大值1.05×10 -6，平均0.31×10 -6。在甲醛去除方式之初探結果，200ppm之二氧化氯超音波霧化機與HEPA濾心及活性炭濾網空氣清靜機去除率為90%以上。根據本研究結果，此次所測量之KTV室內休閒環境確實存在甲醛濃度偏高問題，而經由潛在暴露途徑，發現污染源應為消費者吸煙行為以及建材、室內裝修使用之材料、塗料等。最後建議KTV在設置或整修時應採用無甲醛或低甲醛釋放之建材、塗料，同時確實區隔吸煙與非吸煙包廂之空調系統，並可採取可行之甲醛去除方法，例如：加強通風換氣量，HEPA濾心及活性炭濾網等。關鍵字: 甲醛、KTV、暴露途徑分析[[abstract]]Abstract There have been an increasing number of instances where occupants of a building have complained of a general feeling of being uncomfortable. This phenomenon is appearing in the medical literature as a concept called “sick building syndrome”. In Taiwan, there has been growing concern in the past decade over health complaints attributed to the poor indoor air quality. However, little research is concerned about the indoor air quality (IAQ) problems in Taiwan and no adequate approach for indoor entertainment managers to assess the IAQ has been developed. In addition, formaldehyde is regarded as an important indoor pollutant that will affect the health of people. Hence, the purpose of this study is to establish the formaldehyde audit approach for indoor entertainment buildings with the portable equipment, Formaldemeter 400. Seven KTV buildings were selected as example to investigate the formaldehyde risk to guests and staff, since many people in Taiwan like to sing songs in the KTV. According to the results of this study, the concentrations of formaldehyde exceed the recommended threshold level (0.1ppm) in Taiwan. In addition, the pollution sources of formaldehyde at KTV may be urea-formaldehyde form insulation (UFFI), decoration, wood products, and smoking activities based on the potential exposure pathway analysis. Finally, some air control equipments were also tested to solve formaldehyde problems in order to provide more health and comfortable interior environment for guests and staff. Key words: Formaldehyde, KTV, Exposure pathway analysi