茴香醚在葡萄糖基多孔碳材料上缓释机理

选择葡萄糖为碳源制备了一种多孔碳材料,对材料进行孔隙结构表征,研究材料孔隙结构对茴香醚脱附扩散机制的影响。应用重量法测定茴香醚在不同吸附剂上的脱附动力学曲线,建立扩散系数D_e估算模型,然后计算出茴香醚在吸附剂上的扩散系数D_e（t）-q（t）关系曲线,根据扩散系数值的大小划分扩散机理区域,讨论吸附剂的孔隙结构对茴香醚在吸附剂材料上扩散机制的影响。研究结果表明,所制备样品的比表面积可达1133～3153 m²·g⁻¹,茴香醚在吸附剂上的吸附量可达到1050 mg·g⁻¹;茴香醚香料分子在3种材料上的脱附扩散都经历了一般扩散、Knudsen扩散和表面扩散。吸附剂的孔隙结构对茴香醚香料分子在材料上的脱附扩散机制有影响,其微孔比例越高,茴香醚分子在此吸附剂上以表面扩散机制进行脱附所占比例越高。茴香醚分子在3种吸附剂上的脱附均以Knudsen扩散和表面扩散为主,约占78%～83%。本研究成果对于指导香料物质缓释材料的制备具有实际指导和借鉴意义。     

MIL-100(Fe)中乙醇对低挥发性香兰素的协同脱附研究

提出“高挥发性分子协同脱附”策略,即利用高挥发性乙醇分子与低挥发性香料香兰素分子间的氢键作用,提升香兰素/乙醇MIL-100（Fe）共吸附体系中香兰素分子在MIL-100（Fe）上的脱附效率,并通过分子模拟计算香兰素与乙醇分子间的氢键作用,以及MIL-100（Fe）中香兰素和乙醇之间结合能的影响关系。结果发现：MIL-100（Fe）对香兰素乙醇溶液中的香兰素具有较高的吸附量 （780 mg/g）,并且将吸附香兰素后MIL-100（Fe）在60℃干燥预处理后,由于乙醇的协同脱附作用使香兰素在MIL-100（Fe）上的脱附效率显著上升,其脱附峰温为190℃。同时,考察不同香兰素吸附量对MIL-100（Fe）上香兰素脱附率的影响,发现香兰素的脱附率随香兰素吸附量的增加呈现先增加后下降的趋势,在吸附量约606 mg/g条件时达到最大脱附率（59.1%）。最后,采用分子模拟计算方法发现香兰素和乙醇之间存在强氢键作用,导致在乙醇存在的条件下香兰素与MIL-100（Fe）之间的结合能从-103.47 kJ/mol下降到-66.58 kJ/mol,使得香兰素分子更容易从MIL-100（Fe）上脱附。     

Fe浸渍污泥生物炭对含Cd(Ⅱ)废水的吸附性能研究

通过城市污泥热解制备污泥生物炭(BC),采用FeCl_3溶液浸渍污泥生物炭后制备出磁性污泥生物炭(MBC),对比了BC与MBC去除水溶液中Cd(Ⅱ)的能力。考察溶液初始pH、吸附时间、吸附温度以及Cd(Ⅱ)初始浓度对BC和MBC去除Cd(Ⅱ)效果的影响。结果表明,BC和MBC均符合拟二级动力学吸附模型;Langmuir吸附等温模型能够更好地描述BC和MBC去除Cd(Ⅱ)的过程。在溶液初始pH为6.0,生物炭投加量为10 mg,Cd(Ⅱ)质量浓度为10～150 mg/L的溶液25 mL,吸附时间为360 min,温度为25℃的最佳条件下,BC和MBC对Cd(Ⅱ)最大的吸附量分别为76.93 mg/g和167.42 mg/g。经过5次吸附解吸试验,MBC的Cd(Ⅱ)去除率保持在90%以上,BC的Cd(Ⅱ)去除率在55%左右,说明MBC具有更好应用于去除含Cd(Ⅱ)废水的能力。     

硫酸钙/污泥基生物炭对水中铅的吸附性能研究

将硫酸钙作为添加剂与污泥共热解制备硫酸钙/污泥基生物炭(SBC),并使用BET、SEM、FTIR和XRD表征,研究了其对Pb~(2+)的吸附去除特性。结果表明,硫酸钙已负载在生物炭表面并对去除Pb~(2+)有促进作用。当温度为25℃,初始pH为5,SBC投加量为0.4 g/L,吸附时间为240 min时,Pb~(2+)去除率可达99.69%。Langmuir等温吸附模型能更好地描述SBC对Pb~(2+)的吸附过程,最大吸附量为280.899 mg/g;SBC对Pb~(2+)的吸附更符合准二级动力学模型,该吸附过程可能以化学吸附为主;热力学分析表明SBC对Pb~(2+)的吸附是自发的吸热过程,升温有利于吸附。     

Fe基MILs材料的制备与应用研究进展

金属-有机骨架化合物(Metal-Organic Frame-works,MOFs)是由无机金属离子或离子簇与有机配体配位而成的一类具有周期性网状结构的新型多孔晶体材料。众多MOFs材料中,Fe基拉瓦锡骨架材料(Materials of Institute Lavoisier Frameworks,MILs)因具有良好生物相容性、独特的骨架柔性、突出的比表面积及高度稳定性,在医学、传感、催化等领域有着广泛的应用前景。研究者们通过合成方法创新、结构修饰以及与其他材料复合等方式对Fe基MILs的结构与性能进行优化,进一步提升了Fe基MILs材料及相关材料的实际应用效果、扩展了其应用范围。本文从Fe基MILs的种类及其结构特征入手,重点综述了其常见的合成方法及改性方法,总结了Fe基MILs在药物载体、传感、吸附和催化等方面的应用,在此基础上讨论了Fe基MILs在上述领域中的应用优势及局限性,并对其发展趋势进行了展望。     

污泥基生物炭的水热法制备及吸附性能研究

以城镇污水处理厂剩余污泥为原料,通过水热法制备生物炭,并研究所得生物炭在不同条件(吸附剂投入量、溶液浓度、pH值和温度)下对刚果红废水的吸附效果。研究结果表明,所得生物炭产率高,且在酸性条件下对刚果红具有较好的吸附性能;温度对污泥基生物炭吸附性能的影响很小;当体系反应温度为25℃,溶液pH值为3时,投加2 g/L生物炭,可将20 mg/L的刚果红废水吸附完全。     

生物基竹炭材料的制备及其性能研究

以180目竹粉为原料,利用水热碳化方法,研究了硫酸浓度、碳化温度和碳化时间对竹炭收率的影响。结果表明,在硫酸浓度为85%,碳化温度为90℃,碳化时间为6 h时,竹炭收率可达62%。得到的竹炭材料通过红外光谱、热重分析及扫描电镜手段进行表征。     

污泥基生物炭处理酸性含U（Ⅵ）废水的效能与机理

通过城市污泥(SS)慢速热解制备污泥基生物炭(SSB),并研究初始pH、投加量、共存离子、吸附时间和温度等因素对SSB去除U(Ⅵ)的影响,探讨吸附动力学和吸附等温线特征。通过元素分析、扫描电镜(SEM)、傅里叶红外光谱(FTIR)、X射线衍射(XRD)和X射线光电子能谱(XPS)分析U(Ⅵ)吸附去除的机理。结果表明SSB去除U(Ⅵ)的适宜条件为:pH=3、投加量1 g/L、吸附时间240 min;在此条件下,在温度30℃时最大吸附量为34.51 mg/g。吸附动力学符合拟二级动力学模型;Langmuir吸附等温模型能更好描述生物炭对U(Ⅵ)的吸附行为。U(Ⅵ)吸附去除机理主要包括静电作用,与Si—O—Si的n-π相互作用,与羟基(—OH)、羧基(—COOH)的配位络合。通过5次吸附-解吸试验发现,U(Ⅵ)去除率和SSB再生率均在80%以上。本研究表明污泥基生物炭具备处理与修复酸性含U(Ⅵ)废水污染的潜力。     

含三羟基功能基吸附树脂的合成及对硼酸吸附性能的研究

以二乙烯基苯、丙烯酸甲酯为原料,合成聚丙烯酸甲酯树脂,通过聚丙烯酸甲酯树脂与三羟基甲基氨基甲烷的反应将醇键合到聚丙烯酸甲酯树脂上得到除硼树脂(简称KEN树脂)。通过测定树脂的含水量、红外光谱以确定树脂结构,研究了该种树脂对水溶液中硼酸的吸附、脱附性能。     

Storage and release properties of pheneylethanol and anisole flavor on Fe-based silkworm excrement biocarbon

The silkworm waste from the silkworm was selected as the carbon source, and ZnCl₂ and FeCl₂ were used as activators to obtain a Fe-doped highly graphitized porous biochar material Fe/Z-ASE through a one-step synthesis method. The fabricated Fe/Z-ASE was tested for the adsorption and sustained-release kinetics of pheneylethanol and anisole while their mutual interaction and intermolecular interactions were evaluated by quantum chemical calculation. The silkworm feces exhibited a well-developed pore structure, high surface graphitized carbon content, high BET surface area (950.9 m²/g), more than 60% mesopores and uniform distribution of Fe. Fe/Z-ASE exhibited hydrophobic surface and weak polarity, while anisole realized higher adsorption capacity (510 mg/g) and diffusion rate of 1.7×10^-2 min^-1 than that of phenylethanol under variable anisole adsorption amounts (150—510 mg/g). Density functional simulations suggested anisole and phenylethanol as weak bases and hence interacted with the weakly acidic adsorption sites (Fe-C) on the Fe/Z-ASE, while the relatively higher basicity of anisole endorsed it stronger interaction with Fe/Z-ASE. Molecular dynamics analysis showed strong hydrogen bonding between pheneylethanol molecules while no such interaction existed among anisole molecules, which hindered the desorption of pheneylethanol molecules under high initial adsorption capacity as compared to those of anisole.     

蚕沙基多孔炭表面氧化改性对农药噻虫嗪吸附及缓控释影响

选用桑蚕废弃物蚕沙为炭源,通过炭化活化的方式获得了一种高比表面的中微双孔道生物炭材料SCSE,并采用不同氧化剂对其表面氧化处理以调控材料孔径和表面积对农药噻虫嗪分子的吸附作用力,以实现SCSE材料对农药噻虫嗪的缓控释,并系统研究了氧化改性后材料的比表面积、孔径和表面基团性质的变化对材料吸附噻虫嗪的热力学和动力学平衡以及噻虫嗪的释放动力学等性能的影响。结果表明：SCSE孔隙结构发达,其BET比表面和孔容分别为1290.95 m²/g和0.690 cm³/g;在室温下,该材料对噻虫嗪分子的吸附容量达到560 mg/g。噻虫嗪在四种SCSE上的释放动力学可分为快速持续释放过程和慢速释放过程两个过程,其中快速持续释放过程的释放动力学常数约是慢速释放过程的29～34倍;其中硝酸改性后的SCSE-HN对噻虫嗪的释放比例最大,释放速度最快。本实验所获得的四种SCSE材料对噻虫嗪的释放均表现出长效释放效力。按照一般农作物的需药量,该吸附剂只要按照0.5 g/（d·m²）的投入量便能很好地对农作物进行长效的虫害防治（>40 d）。     

超声波辅助混合溶剂提取蚕沙中叶绿素的工艺研究

以石油醚-丙酮混合溶剂为提取剂,采用超声波辅助法提取蚕沙中叶绿素,以叶绿素提取率为目标,对超声时间、超声温度、超声功率、固液比、助剂(丙酮)含量和提取次数进行优选研究。结果表明,最佳提取工艺为提取次数4次,助剂(丙酮)含量20%,固液比1∶4(g/mL),超声时间50 min,超声功率90 W,超声温度45℃。在此优化条件下,蚕沙中叶绿素提取率为90.6%。     

氟吗啉对家蚕的毒性和安全性评价

研究了氟吗啉对家蚕的胃毒、触杀、熏蒸毒性,并进行安全性评价。试验结果表明：氟吗啉对家蚕2龄起蚕胃毒毒性的LC50为10548．4mg／L;对家蚕触杀毒性的结果为10000．0mg/L浓度以下对2龄起蚕没有毒性作用;对家蚕熏蒸毒性的结果为10000．0mg／L浓度以下对2龄起蚕没有毒性作用。与氟吗啉的推荐使用剂量100-200mg/kg相比,氟吗啉对家蚕安全,对家蚕毒性为“低毒”。     

吸附二甲胺/乙二胺的胺化催化剂脱附性能研究

以自制的不同元素量比的无载体Cu、Ni(2∶1～32∶1)二元胺化催化剂作为研究对象,进行催化吸附二甲胺及乙二胺,用程序升温脱附仪在50～700℃进行脱附性能研究。用脂肪醇制叔胺的胺化反应进行了催化剂评价。结果表明,乙二胺的脱附量0.61067mL/g远大于二甲胺的脱附量0.16585mL/g,说明乙二胺对催化剂表面活性中心的吸附力远强于二甲胺,胺化反应时不能及时完全脱附,使催化剂中毒,以致胺化反应不能进行,而二甲胺可以使胺化反应顺利进行。     

Effect of ligand chain length on hydrophobic charge induction chromatography revealed by molecular dynamics simulations

Hydrophobic charge induction chromatography (HCIC) is a mixed-mode chromatography which is advantageous for high adsorption capacity and facile elution. The effect of the ligand chain length on protein behavior in HCIC was studied. A coarse-grain adsorbent pore model established in an earlier work was modified to construct adsorbents with different chain lengths, including one with shorter ligands (CL2) and one with longer ligands (CL4). The adsorption, desorption, and conformational transition of the proteins with CL2 and CL4 were examined using molecular dynamics simulations. The ligand chain length has a significant effect on both the probability and the irreversibility of the adsorption/desorption. Longer ligands reduced the energy barrier of adsorption, leading to stronger and more irreversible adsorption, as well as a little more unfolding of the protein. The simulation results elucidated the effect of the ligand chain length, which is beneficial for the rational design of adsorbents and parameter optimization for high-performance HCIC.     

蚕蛹中蛋白质与甲壳分离的研究

以脱脂蛹为原料,采用电子光学显微分析技术,观察酸、碱浸泡样组织结构变化,确定了碱法为蛋白质与甲壳素的分离方法。选定了NaOH溶液为分离试剂,就工艺条件(温度、碱浓度、固液比、时间)对蚕蛹蛋白与甲壳素分离效果的影响进行了研究。结果表明,在本实验条件下,最佳工艺条件:温度80℃,固液比1:12,时间10min,碱浓度1(wt)%。甲壳得率为2.46%,粗蛋白回收得率为78.91%。     

Corrosion of amorphous and nanocrystalline Fe-based alloys and its influence on their magnetic behavior

Nanocrystalline soft magnetic materials with low coercivity, high saturation magnetization and high permeability are commonly used as cores in transformers and generators in stress and field sensors. The influence of factors connected with corrosion is almost impossible to eliminate. In the present work, a comparative study of the electrochemical behavior of Fe₇₈Si₁₃B₉ and Fe_73.5Si_13.5B₉Nb₃Cu₁ amorphous and nanocrystallized alloys, tested in 0.5 M NaCl solution, has been performed by linear polarization and electrochemical impedance spectroscopy methods. Changes of magnetic properties including coercivity, induction and magnetic retentivity were analyzed. These properties were investigated as a function of the structure of primary amorphous ribbons and as a function of corrosion environment type, in which longitudinally and transversely cut ribbon specimens were exposed for 15 days. The best magnetic properties were found for the Fe₇₈Si₉B₁₃ ribbon after a structural relaxation at a temperature of 350 °C for an hour and for the Fe_73.5Si_13.5B₉Nb₃Cu₁ ribbon after a primary crystallization at a temperature of 550 °C for an hour. Corrosion did not cause the direct degradation of the magnetic properties of the Fe₇₈Si₉B₁₃ and Fe_73.5Si_13.5B₉Nb₃Cu₁ alloys. The corrosion processes occurring on the surface of the Fe_73.5Si_13.5B₉Nb₃Cu₁ alloy ribbon with the amorphous structures improve induction B_s. Most probably it is connected with the decrease of undesirable stresses blocking a motion of magnetic domain walls on the ribbon surface. Changes of corrosion mechanism depending on structure and applied solution were analyzed. The electrochemical impedance experiment were performed at open circuit potential for amorphous and nanocrystalline specimens. Two electrochemical corrosion mechanisms of Fe_73.5Si_13.5B₉Nb₃Cu₁ alloy in 0.5 M NaCl solution were found. Charge transfer control mechanism is typical for amorphous (as received) alloys. Mixed mechanism-mass transport and charge transfer controlled was observed for nanocrystalline Fe_73.5Si_13.5B₉Nb₃Cu₁ alloy.