氧化石墨的制备及其有机化处理

Graphite oxide(GO) was successfully prepared by using expandable graphite， which is a new starting material instead of the normally adopted natural graphite. XRD and XPS data indicated that， in the same reaction condition due to the application of expandable graphite， the extent of oxidation for the product， GO， was considerably en-hanced and the period required for oxidation was greatly shortened. In addition， the prepared GO was modified by surfactant， that is the new sample， S-GO， was obtained. As a consequence the extended interlayer space has proved itself to be successfully intercalated by the surfactant.     

Zn/Al/Tyr摩尔比对Tyr/Zn-Al-LDH纳米复合物的影响

The intercalation of amphoteric amino acid tyrosine （Tyr） into LDH by co-precipitation method was systematically studied. The influence of initial molar ratios （R） of LDH to Tyr has also been examined. Powder X-ray diffraction, Fourier transform infrared spectroscopy, specific surface areas and pore size distributions, and thermal analysis have been employed for the characterization of the nanocomposites. The nanohybrids were found to have an expanded layered structure except the samples prepared with low R values, indicating that the biomolecules were intercalated into the gallery as anions. The intercalation of amino acids resulted in the increase of the surface areas and pore volumes, and the value of surface areas and pore volumes increased with enhancement of biomolecules intercalated. TEM analysis revealed that with increasing biomolecules into the gallery, the nanohybrids were changed from hexagonal particles to spherical ones. Moreover, the configuration of Tyr anions was varied under different R values, changed from monolayer to bilayers with more biomolecules intercalating into the gallery.     

Regeneration and reuse of anode graphite from spent lithium-ion batteries with low greenhouse gas (GHG) emissions

Regenerating spent graphite(SG) from retired lithium-ion batteries(LIBs) can effectively avoid resource waste. However, the technology is challenged by the impurity content and energy consumption. In this study, micro-expanded graphite(MEG) was synthesized by one-step oxidation method using waste LIBs anode graphite as material and perchloric acid as intercalation and oxidant agent. Then, its performance as a LIBs anode material were investigated as well as the greenhouse gas(GHG) emissions of t...     

Congener-derived template to construct lithiophilic organic-inorganic layer/interphase for high volumetric capacity dendrite-free Li metal batteries

The development of lithium-metal batteries(LMBs) is seriously restricted by the out-of-control dendrites growth and infinite volume expansion. Herein, a pervasive organic-inorganic layer construction strategy is reported for the composite lithium metal anode with congener-derived organic-inorganic solid electrolyte interphase(SEI). In this strategy, the organic-inorganic Ag@polydopamine(Ag@PDA) layer is coated on the arbitrary substrates by a simple two-step method. The thin and stable congener-...     

Edge and lithium concentration effects on intercalation kinetics for graphite anodes

Graphite interfaces are an important part of the anode in lithium-ion batteries(LIBs),significantly influencing Li intercalation kinetics.Graphite anodes adopt different stacking sequences depending on the concentration of the intercalated Li ions.In this work,we performed first-principles calculations to comprehensively address the energetics and dynamics of Li intercalation and Li vacancy diffusion near the no n-basal edges of graphite,namely the armchair and zigzag-edges,at high Li concentrat...     

Chitosan nanoparticles crosslinked by glycidoxypropyltrimethoxysilane for pH triggered release of protein

pH-responsive-chitosan nanoparticles for the control release of protein drug were prepared by combining two-step crosslinking method,in which chitosan was subsequently crosslinked by sodium tripolyphosphate(TPP)and glycidoxypropyltrimethoxysilane (GPTMS).Compared with TPP crosslinked chitosan particles,the two-step crosslinked nanoparticles were not only pH-responsive but also more stable in wide pH range.Fluorescein isothiocyanate(FITC)labeled anti-human-IgG antibody was used as a model protein drug for...     

Structure and Antibacterial Activity of Modified Montmorillonite

<正>Tetradecyldimethylbenzyl ammonium salt(TDMBA) cations were intercalated into sodium montmorillonite (Na-MMT) by an ion exchange reaction.The resulting TDMBA-MMT was characterized by Fourier-transform infrared spectroscopy(FTIR),thermogravimetric analysis(TGA),and X-ray diffraction(XRD).Moreover,the antibacterial activity and water-resistance of TDMBA-MMT were investigated.The results show that TDMBA cations are intercalated into the Na-MMT.The onset temperature of decomposition of TDMBA cations in TDMBA-MMT is raised about 60℃higher than that of tetradecyldimethylbenzyl ammonium chloride(TDMBACl),and the d_((001)) spacing enlarged from 1.23 nm to 2.10 nm.0.1 mg/mL TDMBA-MMT is fully enough to kill all the Staphylococci aureus(S.aureus) and more than 99.99%of the Escherichia coli(E.coli) in a sample solution within 6.0 h touch,and the TDMBA-MMT also shows long acting properties.     

Effect of Different Organic Modifiers on the Tensile Properties of PVC／EVA／Montmorillonite Composites

Poly (vinyl chloride)/ethylene-vinyl acetate/montmorillonite (PVC/EVA/OMMT) composites were prepared by melt blending method. Two kinds of montmorillonites were organically modified by trimethyloctadecyl ammonium and dimethyl bis (hydrogenated tallow) ammonium, respectively. The morphology and tensile properties of the resultant composites were discussed in terms of the modifier type and OMMT content. The PVC/EVA/OMMT composites have intercalated structure, which is independent of the polarity of the modifiers, while the tensile properties show strong dependence on the modifier type. The OMMT modified by polar modifier gives higher tensile ductile and strength of PVC/EVA/OMMT composites.     

Investigation of interfacial processes in graphite thin film anodes of lithium-ion batteries by both in situ and ex situ infrared spectroscopy

Graphite thin film anodes with a high IR reflectivity have been prepared by a spin coating method. Both ex situ and in situ microscope FTIR spectroscopy (MFTIRS) in a reflection configuration were employed to investigate interfacial processes of the graphite thin film anodes in lithium-ion batteries. A solid electrolyte interphase layer (SEI layer) was formed on the cycled graphite thin film anode. Ex situ MFTIRS revealed that the main components of the SEI layer on cycled graphite film anodes in 1 mol L -1 LiPF6 /ethylene carbonate + dimethyl carbonate (1:1) are alkyl lithium carbonates (ROCO2 Li). The desolvation process on graphite anodes during the initial intercalation of lithium ion with graphite was also observed and analyzed by in situ MFTIRS.     

Comparison of magnetic properties of DNA-cetyltrimethyl ammonium complex with those of natural DNA

We prepared the DNA-cetyltrimethyl ammonium complex, as well as the same complex intercalated with stable organic free radicals, and studied their magnetic properties by electron magnetic resonance (EMR) spectroscopy and by measuring the magnetization on a superconducting quantum interference device (SQUID). The UV-vis and CD spectra of DNA-quaternary alkyl ammonium complex (DNA--Q+) in organic solvent clearly demonstrated that it retained the double helical B-form conformation. The interhelical spacing of double strand DNA (dsDNA) increased when the counter ions (Na+) of phosphate groups of the natural DNA were replaced with the long alkyl quaternary ammonium groups. The inter-helical distance of DNA-cetyltrimethyl ammonium (CTMA) was 39.1  as confirmed by X-ray diffractometry. In general, the magnetization of the DNA-CTMA complex solid was found to be significantly lower than that of natural DNA. Moreover, intercalation of the complex with stable organic free radicals did not improve magnetization, which again was in marked contrast to natural DNA. EMR spectroscopic behavior of the complex in the solid state also was quite different from that of natural DNA: The unique broad EMR signal of natural DNA in the low field region with g-value greater than 10 disappeared in the DNA-CTMA complex.     

十六烷基三甲基溴化铵插层氧化石墨结构的分子模拟

利用分子模拟方法研究了十六烷基三甲基溴化铵(C16TAB)分子数对C16TAB/GO插层复合物的结构变化,探讨了C16TAB在GO层间的排列方式,并通过实验数据进行验证。模拟结果表明,优化后GO结构模型的层间距为0.849 nm;C16TAB/GO插层复合物的层间距随着C16TAB分子数的增加呈5个阶梯状逐渐增大,层间距分别为1.56、1.98、2.33、2.76和3.40 nm,插层饱和时C16TAB分子达到28个。实验结果显示,随着C16TAB分子数的增加,C16TAB/GO插层复合物的层间距逐渐增大,插层饱和时为3.40 nm,实验结果与模拟结果能够很好地吻合。C16TAB在GO层间可能的排列方式为1~5层平躺排列或单层平躺、单层倾斜和单层直立,从能量和结构的角度探明了C16TAB在GO层间的最优排列为1~5层平躺排列。     

十六烷基三甲基溴化铵插层氧化石墨结构的分子模拟

利用分子模拟方法研究了十六烷基三甲基溴化铵(C₁₆TAB)分子数对C₁₆TAB/GO插层复合物的结构变化,探讨了C₁₆TAB在GO层间的排列方式,并通过实验数据进行验证.模拟结果表明,优化后GO结构模型的层间距为0.849 nm;C₁₆TAB/GO插层复合物的层间距随着C₁₆TAB分子数的增加呈5个阶梯状逐渐增大,层间距分别为1.56、1.98、2.33、2.76和3.40 nm,插层饱和时C₁₆TAB分子达到28个.实验结果显示,随着C₁₆TAB分子数的增加,C₁₆TAB/GO插层复合物的层间距逐渐增大,插层饱和时为3.40 nm,实验结果与模拟结果能够很好地吻合.C₁₆TAB在GO层间可能的排列方式为1~5层平躺排列或单层平躺、单层倾斜和单层直立,从能量和结构的角度探明了C₁₆TAB在GO层间的最优排列为1~5层平躺排列.     

磷酸铵镁法回收稀土分离废水中镁及氨氮的研究

磷酸铵镁法是一种有效的回收氨氮、磷和镁的方法。本文通过热力学计算,分析了反应过程及pH值对磷酸铵镁生成的影响规律。根据理论分析结果,进行了pH值、磷源、加料方式等因素对氨氮、磷去除率的影响实验。结果表明:以Na3PO4为磷源,通过向氮磷混合液中加入含镁废水,并控制反应液pH值为9时,氮磷镁去除率均可达98%以上,得到沉淀物经X衍射分析为六水磷酸铵镁。     

十聚钨酸季铵盐的合成

利用离子液体首次合成两种十聚钨酸季铵盐{[Bmim]_4W_(10)O_(32)(Bmin=N-甲基-N'-正丁基咪唑)和[Bu~nPy]_4W_(10)O_(32)},其结构经TG,~1H NMR,~(13)C NMR,IR和元素分析表征.     

单斜仲钨酸铵热分解的热化学测定

The heat of the thermal decomposition of monoclini c ammonium paratungstate, (NH4)10H2W12O42•4H2O, was measured in a HT-1000 microcalorimeter using three-step calorimetry and suitable thermochemical cycle. The standard enthalpy of the thermal decomposition reaction at 298.15 K and the standard enthalpy of formation at 298.15 K for monoclinic ammonium paratung-state were obtained to be (430.1± 10.2) kJ•mol－ 1 and－ (13 423.7±14.8) kJ•mol－ 1, respectively.     

改性硝酸铵自敏化结构特征

对经复合表面活性剂处理的改性硝酸铵及普通硝酸铵晶体进行电镜扫描,孔径孔容分布,粒径分布,比表面积测定,抗吸湿结块性,差示量热分析以及爆炸性能的实验研究,结果表明,与普通硝酸铵相比,改性硝酸铵的晶形歧化,比表面积大,富含气孔,大部分的有效孔径座落在介孔范围,有较好的粒度级配,晶变热降低,且晶变点后移,具备自敏化结构特征,并且有良好的抗吸湿结块性,用它代替普通硝酸铵所制得的粉状工业炸药具有良好的物理性能和爆炸性能。     

单斜仲钨酸铵热分解的热化学测定

在钨的冶炼过程中,仲钨酸铵是必须的中间原料 .从溶液中结晶仲钨酸铵时,根据结晶条件的不同,可以得到不同类型的结晶 [1].一般在较低的温度时（低于 323 K）,得到三斜仲钨酸铵 (NH4)10H2W12O42· 10H2O,在较高温时（高于 323 K）,得单斜仲钨酸铵 (NH4)10H2W12O42· 4H2O.工业生产中,单斜仲钨酸铵是常见的产品 .仲钨酸铵的质量直接决定钨粉的质量,因此仲钨酸铵热力学性质对于控制其结晶条件及结晶的热分解条件具有重要的指导意义 .但迄今,很少有关于单斜仲钨酸铵的热力学性质的报导 .本文用双子型热导式微量热量计,根据单斜…     

Synthesis of Chitosan Quaternary Ammonium Salts

Chitosan has a wide scale of applications1-3. Interestingly, some antibacterial and antifungal activities have been described with chitosan and modified chitosan derivatives4-6. In polycationic biocides, generally, it is reasonably assumed7 that the charge density of the polyelectrolyte increases with increase in the molecular weight of its single coil, which leads to the enhanced adsorption of polycations onto the negatively charged cell surface. This is also favorable for the binding of t…     

Ammonium based anion receptors

Selective anion recognition has been a tremendous challenge to chemists over the decades. However, with the advent of the concepts inherent in ‘supramolecular chemistry,’ the field now flourishes. Of the major types of receptors, polyamines have been studied widely as anion hosts by a number of researchers. Both electrostatic interactions and hydrogen bonds between protonated amines and the anion guests govern the binding in these systems. Exceptions to this rule are found in the quaternary ammonium systems, which utilize primarily electrostatic interactions and topological complementarity for binding purposes. This review focuses only on amine-based hosts, and is divided into acyclic and macrocyclic categories, the latter of which are based on cyclic dimension. The resulting four categories are: acyclic, monocyclic, bicyclic, and polycyclic. Within the major categories, binding is discussed according to the nature of the anion target, i.e. ‘simple’ inorganic anions, organic anions, and anionic metal complexes.     

功能高分子聚丙烯酸铵的研制

以环己烷为连续相、水为分散相、氨水部分中和的丙烯酸为单体、K2S2O8为引发剂，N，N－亚甲基双丙烯酰胺为交联剂，采用反相悬浮聚合法合成了功能高分子材料－聚丙烯酸铵高吸水性树脂。研究了乳化剂、引发剂和交联剂用量、pH值、反应湿度等对吸水率的影响，得到的高吸水性树脂最大吸水率为1237mL/gR,其最大吸生理盐水率为114mL/gR。利用SEM，IR对其进行了表征。SEM分析表明，如果采取适当的工艺可以得到粒状产品。