纸塑铝复合包装材料各组分共热解产物分析

以甲酸分离枕型利乐包所得的纸、聚乙烯、铝作为实验材料,使用热重红外联用(TG-FTIR)分析技术,研究了单一组分热解产物特性和组分共热解机理。结果表明:共热解时纸和聚乙烯之间存在协同作用,且在TG-FTIR失重峰位置附近产生的影响尤为明显;铝在共热解时具有催化剂的作用,会促进聚乙烯的分解。为实现废弃纸塑铝复合包装材料的资源化利用提供科学参考和实验依据。     

中温沥青中甲苯可溶组分的热解特性及热转化产物的性质

以中温煤沥青的甲苯可溶组分为原料,进行元素分析和TG/DTG分析,并且利用偏光显微镜、X射线单晶衍射仪、拉曼光谱以及相应的分峰拟合等数学方法对热转化的产物进行研究。以实验获得的数据为基础,采用Flynn-Wall-Ozawa法和Kissinger-Akahira-Sunose法计算得到反应活化能,采用Satava-Sastak法求解热解反应动力学参数。实验结果表明,中温沥青中甲苯可溶组分的热解反应活化能为E=88.48kJ/mol,指前因子lgA=10.22,反应级数为2级,热解反应机理适合随机成核及其随后的增长模型。1 000℃焙烧后的炭化产物的光学显微组分含量为:镶嵌型23.74%,粗纤维型14.80%,细纤维17.88%,大片结构30.45%。由XRD研究结果可知,趋于规整结构的碳微晶含量为41.86%。Raman光谱分析研究结果表明,石墨结构的碳微晶含量为11.59%,缺陷石墨碳含量为79.31%,无定形碳含量为9.10%。热转化产物具有很好的可石墨化性。     

煤沥青中甲苯可溶物的基础物性研究

以甲苯为萃取剂分别对中温沥青(MP)、氧化改性沥青(OMP)和热缩聚改性沥青(TMP)进行溶剂萃取-热过滤-蒸馏处理,得到三种甲苯可溶物(依次命名为TS1M、TSOM和TSTM)。利用元素分析仪、GPC凝胶渗透色谱、H-NMR、FTIR结合分峰拟合的方法对三种甲苯可溶物的芳香性指数(Iar)、支链化指数(CH_3/CH_2)和芳香缩合度(fa)等基础性质进行了计算研究,利用TGA热分析仪对甲苯可溶物的热解行为进行了研究,并且利用SEM、偏光显微镜(PM)对热解产物的微观结构进行了观察。结果表明:TSM、TSOM和TSTM三种甲苯可溶物的芳香性极佳,Iar指数分别为0. 949、0. 954和0. 987,fa指数依次为0. 967 2、0. 968 7和0. 978 5。TSM、TSOM和TSTM的CH_3/CH_2指数依次为0. 200、0. 297和0. 503,说明三种甲苯可溶物的支链数量和支链长度依次减少。TSM、TSOM和TSTM的热解特征温度依次升高,与三种甲苯可溶物中Iar、fa和CH_3/CH_2的指标相关联。     

废弃电路板真空热解产物特性分析

采用真空热解对废弃电路板进行热解实验,利用FT-IR分析、GC/MS、SEM等技术对真空热解液体、固体及气体产物进行了分析表征,研究了不同真空条件和温度下对热解产物的组成和理化特性.结果表明,液体产物的密度会随着真空度的变化发生改变;在不同真空条件下,产物的组成也有不同,并分析其产生的原因.为进一步探讨废弃电路板的真空热解产物特征提供参考.     

乙炔的等离子体热解产物:富勒烯的合成

乙炔在高频等离子体电弧中高温分解,连续批量合成炭黑烟炱.高分辨透射电镜(HRTEM)观察发现,炭黑粒子大小约为25nm,由无定形碳和结晶不完整的石墨碎片组成.采用紫外/可见吸收光谱(UV-Vis),付立叶变换红外光谱(FT-IR)等分析方法,对其甲苯提取液及结晶产物进行了初步的成份确认,发现其中含有C60/C70富勒烯成份,粗含量达到烟炱的3%左右.     

超声与静电场协同作用对水电导率的影响

超声和静电场的协同作用对水的电导率产生明显的影响。首先通过单独的超声和静电场作用,研究了其对水电导率的影响,并通过改变超声和静电场的强度,发现在一定范围内,随着超声功率的增大,水电导率随时间逐渐提高,而单独的静电场对水的电导率没有明显影响。最后,通过超声和电场的协同作用,发现水的电导率相对其单独作用有了明显的提高,并且,随着超声电功率和静电场强度的增大,水的电导率提高明显。     

不同热解工艺对铁酸铋薄膜结构及导电机制的影响

采用溶胶-凝胶方法和4种不同的热解工艺(350℃/3 min,350℃/90 s,350℃/45 s和250℃/45 s-400℃/45 s)在(111)Pt/Ti/SiO2/Si衬底上制备了厚约为300 nm的BiFeO3薄膜。X射线衍射表征显示350℃/90 s薄膜为纯钙钛矿相,350℃/3 min,350℃/45 s和250℃/45 s-400℃/45 s薄膜含有微量的Bi2Fe4O9杂相,表面形貌证实350℃/90 s薄膜表面平整度最好,微观结构最致密,其他热解工艺处理的薄膜表面存在纳米尺寸的空隙和晶粒间界。电学性能测试方面,350℃/90 s薄膜的介电常数和介电损耗受频率的影响较小,其他薄膜的介电常数和介电损耗在低频范围时随频率的增加急剧降低。导电机制分析表明,350℃/90 s薄膜在低、高电场范围分别符合Ohmic导电和普尔-弗兰克导电机理,350℃/3 min薄膜在低电场时由空间电荷限制导电主导,在高电场时由Fowler-Nordheim(F-N)tunneling导电主导。     

热解条件对热解碳沉积模式和形貌的影响

以丙烯为源物质氩气为稀释气体,研究了沉积温度、丙烯流量、系统总压对沉积物形貌的影响．利用晶体成核－生长理论解释了各种形貌的成因．实验证明随着沉积温度的升高、系统总压的增大,热解碳的沉积由表面化学反应成核－生长模式向熔滴模式和气相成核－生长模式过渡．沉积温度不同丙烯流量对沉积模式影响规律不同．沉积模式随沉积条件的改变决定了热解碳沉积物形貌的改变．     

乙炔的等离子体热解产物：富勒烯的合成

乙炔在高频等离子体电弧中高温分解,连续批量合成炭黑烟炱。高分辨透射电镜（HRTEM）观察发现,炭黑粒子大小约为25nm,由于无定形碳和结晶不完整的石墨碎且成,采用紫外／可见吸收光谱（UV－Vis),付立叶变换红外光谱（FT－IR）等分析方法,对其甲苯提取液及结晶产物进行了初步的成份确认,发现其中含有C60／C70富勒烯成份,粗含量达到烟炱的3％左右。     

颜料协同作用对涂布装饰原纸性能的影响

目的研究颜料协同作用对装饰原纸性能的影响,达到改善纸张表面结构、优化其物理性能的目的。方法优选阔叶木浆和针叶木浆(有效成分的绝对质量比为4∶1)混合打浆至打浆度(SR)38°,再添加二氧化钛填料、PAM、PAE、硫酸铝等抄造装饰原纸;以PVA、阳离子淀粉为胶黏剂,加以蒸馏水、颜料(TiO_2分别与Al_2O_3,Clay,Al_2SiO_5,SiO_2协同)、分散剂、消泡剂、润滑剂、保水剂制备用于装饰纸表面用涂料,采用涂布机和压光机对原纸进行涂布压光,之后浸渍压板,采用凹版进行印刷,探究颜料复配涂布对原纸涂层结构和印刷适性作用。结果颜料协同改性中添加一定的SiO_2颜料有助于纸张表面被有效均匀地涂覆,并能观察到细小的颜料颗粒,形成良好紧密涂层结构,装饰原纸涂布含有SiO_2协同作用颜料后,吸水高度提高了135%,平滑度提高了130%,干抗张强度提高了175%,湿抗张强度提高了160%。印刷性能方面,协同改性添加SiO_2涂料涂布装饰原纸在相对较小的涂层厚度下纸张涂层具有良好的油墨接受性,有助于印刷油墨的吸收固着,进而抑制网点扩大和颜色整体阶调再现范围变大。结论颜料协同改性涂布添加SiO_2有助于改善装饰原纸的物理性能和印刷适性。     

Reversible toluene adsorption on monolithic carbon aerogels

Thirteen monolithic carbon aerogels with different pore textures were used as toluene adsorbents. Adsorption was carried out under both static and dynamic conditions. Under static conditions at 25 degrees C and at saturation, an adsorption capacity as high as 1.36 cm(3) g(-1) or 1180 mg g(-1) was obtained. Toluene adsorption was a reversible process in all carbon aerogels, and the adsorbed toluene was completely recovered by heating them at 400 degrees C. Regenerated adsorbents showed larger surface area and micropore width than the original samples, indicating that no pore blockage was produced. Adsorption under dynamic conditions at 100 degrees C was also completely reversible after at least three consecutive adsorption-desorption cycles. The ability of these carbon aerogels to reversibly adsorb toluene could be useful for their application in thermal swing adsorption or pressure swing adsorption equipment.     

Synergetic effect of Re and Ru on γ/γ′ interface strengthening of Ni-base single crystal superalloys

The synergetic effect of Re and Ru on γ/γ′ interface strengthening of Ni-base SC superalloys has been investigated by performing DMol3 calculations. Results show that the synergetic effect of Re and Ru on the interface strengthening is better than that achieved by the individual Re or Ru due to Re-d/Ru-d, Re-d/Ni-d and Ru-d/Ni-d hybridizations. The electronic mechanism underlying the synergetic effect of Re and Ru on γ/γ′ interface strengthening is related to the charge transfer of electrons and the enhancement of d-bonding hybridization among Re---Ru, Re---Ni and Ru---Ni atoms.     

Effects of pollutant concentration ratio on the simultaneous removal of NH3, H2S and toluene gases using rock wool-compost biofilter

The biological treatment of a tri-component mixed waste gas system in BRC1 and BRC2 biofilters packed with rock wool-compost media was studied. The model gases were NH(3), H(2)S and toluene. The gases were fed initially at about 50-55 ppm each. H(2)S was found to have the shortest start-up while toluene had the longest. Under two different NH(3):H(2)S:toluene concentration ratios of 250:120:55 and 120:220:55 (in ppm) for BRC1 and BRC2, the removal efficiencies of NH(3), H(2)S and toluene were found to be affected by their respective loading rate. On the other hand, toluene removal was observed to be inhibited at H(2)S concentration of 220 ppm as well. Almost complete removal of NH(3) and H(2)S was achieved when loading rate was applied up to 16.14 g-NH(3)/(m(3) bed h) and 36.09 g-H(2)S/(m(3) bed h), respectively. The maximum elimination capacity for NH(3) was determined to be 23.67 g-NH(3)/(m(3) bed h) at 78.6% removal efficiency and for H(2)S, 38.50 g-H(2)S/(m(3) bed h) at 68.1% removal efficiency. The maximum toluene elimination capacity was 30.75 g-toluene/(m(3) bed h) at 87.9% removal efficiency when the concentration of NH(3):H(2)S:toluene was 250:120:55 in BRC1, and was 16.60 g-toluene/(m(3) bed h) at 45.5% removal efficiency when the concentration of NH(3):H(2)S:toluene was 120:220:55 in BRC2. The pressure drops along both columns were low and the ratio of bed compactions over biofilter height was observed to be less than 0.02.     

High dielectric performance of three-component nanocomposites induced by a synergetic effect

Nanosized BaTiO₃ (NBT) was introduced into multi-walled carbon nanotube (MWNT)/poly(vinylidene fluoride) (PVDF) composite with fixed MWNT loading to explore the effect of secondary ceramic filler on dielectric properties of three-component composite. The dielectric constant of (NBT-MWNT)/PVDF composite was enhanced significantly (338 → 637) while the AC conductivity was decreased (7.75 × 10^− 3 S m^− 1 → 3.53 × 10^− 4 S m^− 1) when the volume concentration of NBT was increased up to 0.20. The reason can be the space charge polarization nature and a synergetic effect of NBT/MWNT loading. This can be further confirmed by using an equivalent circuit model to analyze the impedance data.     

甲苯传感器的制作及特性

采用溶胶-凝胶法制备了NASICON(钠超离子导体)固体电解质材料.利用XRD分析了所制备材料的结构,材料的平均粒径约为22nm.以NASICON为离子导电层,Sm_2O_3为敏感电极制作了具有良好敏感特性的C_7H_8气体传感器.在430℃工作温度下,器件对(5-50)×10~(-6)C_7H_8的灵敏度为-75mV/decade.并且对C_7H_8具有较高的选择性和良好的响应恢复特性,器件对5 × 10~(-6)和50×10~(-6)C_7H_8的响应时间分别为45和35秒,恢复时间分别为8和60秒.对器件的敏感机理做以简要的分析.     

P-type ZnO thin film deposited by spray pyrolysis technique: The effect of solution concentration

The aim of this research is to study the role of concentration variations on precursor solution of nitrogen doped ZnO (ZnO:N) thin films which has been prepared by spray pyrolysis technique. SEM micrographs show that ZnO:N films in 0.1 ML concentration have a mono-disperse surface with nano-spheres of 50 nm in diameter. In higher molarities the nano-spheres agglomerate leading to particle formation. For 0.4 ML concentrations this change is observed, where plume like particles are seen over the surface of ZnO:N thin film. This change corresponds also to changes observed in the XRD spectra, where crystal orientation of ZnO:N thin films changes from (002) to (100). All of the ZnO:N thin films have kept their sharp ultra violet absorption edge, but the transparency in visible spectra region decreases as the molarities in precursor solution increase. Photoluminescence spectra at room temperature revealed emissions at 2.33 eV, 2.54 eV and 3.16 eV that can be attributed to the presence of nitrogen in ZnO structure. We also observe that all samples analyzed show a p-type Hall effect behavior, and that as the molarities in the precursor solution increase, the electrical resistivity of the films decreases, due to an enhancement of free carriers, while the mobility decreases. These data prove the capability of spray pyrolysis as a viable technique in preparing p-type TCO materials and so, fully transparent CMOS-like devices.     

The effect of temperature on toluene sorption by granular activated carbon and its use in permeable reactive barriers in cold regions

Granular activated carbon (GAC) has been used as an adsorbent for hydrocarbons in a range of permeable reactive barriers. This work investigates the influence of temperature on adsorption performance. In particular, the influence of temperature in the range of 20 °C to 4 °C on the sorption equilibrium and kinetics of toluene on GAC surface were investigated. The results show that low temperature leads to decreased toluene sorption by GAC and slower reaction kinetics. Sorption kinetics studies show that diffusion coefficients are also lower at 4 °C (3.65 × 10⁻¹³ m² s⁻¹) than 20 °C (5.112 × 10⁻¹³ m² s⁻¹).     

Semicontinuous microcosm study of aerobic cometabolism of trichloroethylene using toluene

A semicontinuous slurry-microcosm method was applied to mimic trichloroethylene (TCE) cometabolic biodegradation field results at the Que-Jen in-situ pilot study. The microcosm study confirmed the process of aerobic cometabolism of TCE using toluene as the primary substrate. Based on the nucleotide sequence of 16S rRNA genes, the toluene-oxidizing bacteria in microcosms were identified, i.e. Ralstonia sp. P-10 and Pseudomonasputida. The first-order constant of TCE-degradation rate was 0.5 day(-1) for both Ralstonia sp. P-10 and P.putida. The TCE cometabolic-biodegradation efficiency measured from the slurry microcosms was 46%, which appeared pessimistic compared to over 90% observed from the in-situ pilot study. The difference in the TCE cometabolic-biodegradation efficiency was likely due to the reactor configurations and the effective time duration of toluene presence in laboratory microcosms (1 days) versus in-situ pilot study (3 days). The results of microcosm experiments using different toluene-injection schedules supported the hypothesis. With a given amount of toluene injection, it is recommended to maximize the effective time duration of toluene presence in reactor design for TCE cometabolic degradation.     

An ultra-sensitive room temperature toluene sensor based on molten-salts modified carbon nitride

In this work, two-dimensional crystalline C₃N₄ (CCN) was obtained by promoting the self-condensation reaction of dicyandiamide in an air atmosphere via the molten salt method. Studies show that compared with polymer-C₃N₄ (PCN) ((9.8 m²/g)), CCN has a larger specific surface area (77.1 m²/g)) and better crystallinity. Additionally, the resistance of CCN in the air is 40 MΩ, 1250 times lower than that of polymer-C₃N₄ (PCN) (∼50000 MΩ). Secondly, when 50 ppm toluene gas analysis flows into the CCN based gas sensor at room temperature, the gas response value is 350. The CCN based gas sensor works for 60 days, or after 25 cycles continuously, the gas response value remains at about 350 (R_g/R_a), which is due to the excellent crystallinity, optimized π conjugate system, and enhanced interlayer van der Waals of CCN. Additionally, the critical effect of crystallinity on the gas sensitivity of carbon nitride is also discussed in detail.     

Comparison of pyrolysis and oxidation actions on chemical and physical property of anthracite coal surface

Hydrophobicity of coal surface is determined by its physical property and chemical composition. Once coal was oxidized or spontaneously ignited under natural conditions, the surface properties would change greatly, which inevitably affect the hydrophobicity of coal surface. To reveal the changing regulations of coal surface’s hydrophobicity after oxidation and pyrolysis treatment, in this paper, two conditions (pyrolysis and oxidation) of heating treatment were used to produce a series of coal surfaces, and then characterizing their physical and chemical properties through SEM and XPS. Meanwhile, induction time and flotation tests were performed to measure the hydrophobicity of coal. Results showed that the pores and cracks were well developed on the coal surface after both oxidation and pyrolysis processes. But they contributed to opposite aspects later in the flotation test. Additionally, the content of oxygen-containing functional groups on the surface decreased after pyrolysis, whereas having a sharp increase after the oxidation process, which predicted that the hydrophobicity of coal surface under two heating conditions would be completely different. Coal after pyrolysis owned a very short induction time, and its flotation recovery was high. For oxidation process, the coal surface became more hydrophilic and their induction time could reach at about 4000 ms, very hard to float.