含氮聚硅氧烷配位体及其与金属离子的络合作用

研究ｎ－β（氨乙基）－γ（氨丙基）三乙氧基硅烷［ＮＨ２（ＣＨ２）２ＮＨ（ＣＨ２）３Ｓｉ（ＯＥｔ）３］与二甲基二乙氧基硅烷［（ＣＨ３）２Ｓｉ（ＯＥｔ）２］共水解，制备含－（ＣＨ２）３ＮＨ（ＣＨ２）２ＮＨ２功能基的聚硅氧烷配位体。用ＩＲ、１ＨＮＭＲ和元素分析法对共聚产物的结构进行了分析，同时用紫外－可见光谱法和ＳＥＭ考察了共聚产物与Ｃｕ２＋等金属离子的络合作用。结果发现，两种单体进行了共水解反应，而且随着ＮＨ２（ＣＨ２）２ＮＨ（ＣＨ２）３Ｓｉ（ＯＥｔ）３比例增加，水解程度提高。共聚产物可以与Ｃｕ２＋离子形成稳定的络合物，但不能与Ｚｎ２＋离子或Ａｌ３＋离子形成稳定的络合物或螯合物。     

水滑石焙烧产物Mg（Al）O为载体的Pt催化剂的正己烷临氢反应性能

制备了以水滑石焙烧产物－Ｍｇ－Ａｌ复合氧化物为载体的Ｐｔ催化剂，并考察了它在氢存在下的烃类转化反应性能，表明此类催化剂具有比一般的Ｐｔ／Ａｌ２Ｏ３更好的正己烷脱氢环化和异构化反应活性和选择性，更低的氢解反应活性。分别制备了以Ｈ２ＰｔＣｌ６、Ｐｔ（ＮＨ３）４（ＯＨ）２和Ｐｔ（ＮＨ３）４Ｃｌ２为浸渍剂的催化剂，其中以用Ｐｔ（ＮＨ３）４Ｃｌ２和Ｐｔ（ＮＨ３）４（ＯＨ）２制备的催化剂的脱氢环化反应和异构化     

N—取代三氯乙酰胺合成N,N“—多亚甲基双（N‘—（4—氯苯基）脲

通过Ｎ－取代三氯乙酰胺与不同的脂肪二胺反应，合成了５种新的Ｎ，Ｎ”－多亚甲基双（Ｎ’－（４－氯苯基）脲（ＡｒＮＨＣＯＮＨ（ＣＨ２）ｎＮＨＣＯＮＨＡｒ，ｎ＝２～６，Ａｒ＝４－ＣｌＣ６Ｈ４）其结构经元素分析，ＨＮＭＲ和ＩＲ证实。     

（四甲基二硅撑）双（3—三甲硅基环戊二烯基）—四羰基二铁…

标题化合物（Ｍｅ２ＳｉＳｉＭｅ２）〔η＾５－（３－Ｍｅ３ＳｉＣ５Ｈ３）Ｆｅ（ＣＯ）２〕２／（μ－ＣＯ）２（Ａ）分子中的Ｆｅ－Ｆｅ键被钠汞齐还原断裂，生成相应的双铁负离子，分别与ＭｅＣＯＣｌ、ＰｈＣＯＣｌ、ＰｈＣＨ２Ｃｌ、ＣｌＣＨ２ＣＯＯＣ２Ｈ５和Ｐｈ３ＳｎＣｌ进行亲核取代反应，生成在铁原子上引入相应取代基的产物（Ｍｅ２ＳｉＳｉＭｅ２）〔η＾５－（３－Ｍｅ３ＳｉＣ５Ｈ３）Ｆｅ（ＣＯ）２Ｒ〕２（Ｒ：Ｍ     

（四甲基二硅撑）双（3－三甲硅基环戊二烯基）－四羰基二铁的反应性

标题化合物（Ｍｅ_２ＳｉＳｉＭｅ_２）［η￣５－（３－Ｍｅ_３ＳｉＣ_５Ｈ_３）Ｆｅ（ＣＯ）_２］_２／（μ－ＣＯ）_２（Ａ）分子中的Ｆｅ－Ｆｅ键被钠汞齐还原断裂，生成相应的双铁负离子，分别与ＭｅＣＯＣｌ、ＰｈＣＯＣｌ、ＰｈＣＨ_２Ｃｌ、ＣｌＣＨ_２ＣＯＯＣ_２Ｈ_５和Ｐｈ_３ＳｎＣｌ进行亲核取代反应，生成在铁原子上引入相应取代基的产物（Ｍｅ_２ＳｉＳｉＭｅ_２）［η￣５－（３－Ｍｅ_３ＳｉＣ_５Ｈ_３）Ｆｅ（ＣＯ）_２Ｒ］_２（Ｒ：ＭｅＣＯ（１），ＰｈＣＯ（２），ＰｈＣＨ_２（３），ＣＨ_２ＣＯＯＣ_２Ｈ_５（４），Ｐｈ_３Ｓｎ（５），Ｉ（６））。Ａ在氯仿中与碘反应，得到Ｆｅ－Ｆｅ断裂的双铁碘化物，但在苯中与过量碘反应，则得到Ｆｅ－Ｉ－Ｆｅ桥联的离子型化合物（Ｍｅ_２ＳｉＳｉＭｅ_２）［η￣５－（３－Ｍｅ_３ＳｉＣ_５Ｈ_３）Ｆｅ（ＣＯ）_２］_２Ｉ·Ｉ（７）。化合物６的晶体和分子结构经Ｘ射线衍射测定，６属单斜晶系，Ｐ２１／ｃ空间群，ａ＝１．７２１７（４）ｎｍ，ｂ＝０．７７５３（２）ｎｍ，Ｃ＝１．３６２９（７）ｎｍ，β＝１０３．８０（３）°，Ｖ＝１．７６７（２）ｎｍ３，Ｚ＝４，Ｄｃ＝１．６２９９·ｃｍ－１，最终偏差因子Ｒ＝０．０５４。     

N－取代三氯乙酰胺合成N，N″－多亚甲基双［N′－（4－氯苯基）］脲

通过Ｎ－取代三氯乙酰胺与不同的脂肪二胺反应，合成了５种新的Ｎ，Ｎ″－多亚甲基双［Ｎ′－（４－氯苯基）］脲［ＡｒＮＨＣＯＮＨ（ＣＨ２）ｎＮＨＣＯＮＨＡｒ，ｎ＝２～６，Ａｒ＝４－ＣｌＣ６Ｈ４］，其结构经元素分析、１ＨＮＭＲ和ＩＲ证实     

聚硅氮烷的热分解特性研究

研究了由有机氯硅烷氨解制得的聚硅氮烷（ＰＳＺ）在Ｎ２与ＮＨ３气氛中的热分解特性．结果表明，在Ｎ２气氛中，ＰＳＺ经三个阶段转化为无定形陶瓷，在更高温度下则得到α－Ｓｉ３Ｎ４结晶与β－ＳｉＣ微晶的复合体．β－ＳｉＣ的形成来源于Ｓｉ－ＣＨ３基团的热分解，降低ＰＳＺ中Ｓｉ—ＣＨ３，含量能提高产物中Ｓｉ３Ｎ４的含量．在ＮＨ３气氛中热分解时产生脱碳反应，导致形成无定形态的无机物，它在１５００℃转化为几乎为纯的α－ＳｉＮ４．     

Synthesis and Structure of(NH4)_2 [V2O_4(OCH_2COO)_2]

ＳｙｎｔｈｅｓｉｓａｎｄＳｔｒｕｃｔｕｒｅｏｆ（ＮＨ４）２［Ｖ２Ｏ４（ＯＣＨ２ＣＯＯ）２］ＺＨＯＵＺｈａｏ－ｈｕｉ，ＷＡＮＧＪｉｎｚｈｉ，ＷＡＮＨｕｉ－ｌｉｎａｎｄＴＳＡｌＫｈｉ－ｒｕｉ（ＤｅｐａｒｔｍｅｎｔｏｆＣｈｅｍｉｓｔｒｙ，ＸｉａｍｅｎＵｎｉ...     

N-硅甲基-N-甲酰基苯胺衍生物的合成和生物活性研究

研究了醇钠存在下取代苯胺与氯甲基硅烷在二甲基甲酰胺中的反应。反应产物经元素分析、ＩＲ和１ＨＮＭＲ光谱鉴定为Ｎ－硅甲基－Ｎ－甲酰基苯胺衍生物。合成了２３种通式为ＲＲ′Ｒ″ＳｉＣＨ２Ｎ（ＣＨＯ）的新化合物,对其中１７种进行了生物活性试验。结果表明,个别化合物具有良好的杀菌活性,如ｐ－ＦＣ６Ｈ４Ｓｉ（Ｍｅ２）ＣＨ２Ｎ（ＣＨＯ）·Ｃ６Ｈ４Ｃｌ－ｐ在０．００５％即可１００％杀死芦笋茎枯病菌。     

Selective Reduction of α,β-Unsaturated Amides with NaBH_4/BiCl_3 System

ＳｅｌｅｃｔｉｖｅＲｅｄｕｃｔｉｏｎｏｆα，β－ＵｎｓａｔｕｒａｔｅｄＡｍｉｄｅｓｗｉｔｈＮａＢＨ_４／ＢｉＣｌ_３ＳｙｓｔｅｍＳｅｌｅｃｔｉｖｅＲｅｄｕｃｔｉｏｎｏｆα，β－ＵｎｓａｔｕｒａｔｅｄＡｍｉｄｅｓｗｉｔｈＮａＢＨ_４／ＢｉＣｌ_３Ｓｙｓｔｅ...     

The increased termal stability associated with humic acid anchored onto silica gel

Commercial humic acid (HA) was anchored onto silica gel (SiAPTS) previously modified with 3-aminopropyltrimethoxysilane (APTS). HA was anchored onto SiAPTS through two routes: adsorption and covalent chemical immobilization onto the surface. The adsorption occurred by adding SiAPTS to HA in an aqueous solution, producing SiHA1, while chemical immobilization was performed by reacting HA suspended in N,N-dimethylformamide with SiAPTS, to yield SiHA2. The infrared spectra confirm HA immobilization using both procedures and the termogravimetric results showed that the anchored compounds have significantly thermal stability increased. While natural HA presents a thermal stability up to 200°C, the anchored compound presents a thermal stability near to 750°C. This revised version was published online in July 2006 with corrections to the Cover Date.     

Simultaneous adsorption of copper ions and humic acid onto an activated carbon

In this study, simultaneous adsorption of copper ions and humic acid (HA) from Aldrich onto an activated carbon is investigated. It is found that the HA adsorption in the absence of copper decreases as the pH is increased. It leads to a reduction of 34.7% in the specific surface area of carbon. There exists a critical concentration (CC) of HA for copper adsorption. At HA concentrations < CC, a decrease in copper adsorption is observed; however, the HA improves the adsorption at HA concentrations > CC. An increase in ionic strength can enhance the copper uptake; however, zinc and/or cobalt ions have an insignificant influence on copper adsorption. The adsorption is significantly increased by citric acid, whereas addition of EDTA slightly decreases the uptake. An intraparticle diffusion model is successfully used to describe the copper adsorption kinetics.     

Simultaneous removal of uranium and humic acid by cyclodextrin modified graphene oxide nanosheets

Cyclodextrin-modified graphene oxide nanosheets (denoted as CD/GO) were synthesized by an in-situ polymerization method and characterized by as well as Fourier transform-infrared spectroscopy, X-ray photoelectron spectroscopy, Raman spectroscopy and potentiometric acid-base titration. The characterization results indicated that CD was successfully grafted onto GO surfaces by forming a chemical bond. Mutual effects on the simultaneous removal of hexavalent uranium and humic acid by CD/GO from aqueous solution were investigated. The results indicated that U(VI) and humic acid (HA) sorption on CD/GO were greatly affected by pH and ionic strength. The presence of HA enhanced U(VI) sorption at low pH and reduced U(VI) sorption at high pH, whereas the presence of U(VI) enhanced HA sorption. The surface adsorbed HA acted as a “bridge” between U(VI) and CD/GO, and formed strong inner-sphere surface complexes with U(VI). Sorption isotherms of U(VI) or HA on CD/GO could be well fitted by the Langmuir model. This work highlights that CD/GO can be used as a promising material in the enrichment of U(VI) and HA from wastewater in U(VI) and humic substances obtained by environmental pollution cleanup.     

硝酸氧解法提高泥炭中黄腐酸的产率

硝酸氧解法提高泥炭中黄腐酸的产率;腐植酸;硝酸氧化降解     

铁酸锰/腐植酸复合材料制备及其对亚甲基蓝吸附性能

采用化学共沉淀法合成了一种腐植酸(Humic Acid,HA)包覆铁酸锰型磁性复合材料(MnFe₂O₄/HA)。采用扫描电子显微镜(SEM)、粉末X射线衍射(XRD)和傅里叶变换红外光谱(FT-IR)等技术手段对其进行表征和分析表明,合成产物颗粒大小约200 nm,具有典型的尖晶石结构,腐植酸成功包覆在MnFe₂O₄颗粒表面,饱和磁化强度为34.01 A·m²/kg,在外界低磁场作用下30 s内便可从水溶液分离。 MnFe₂O₄/HA对亚甲基蓝的吸附是一个准二级动力学过程,在2 h达到平衡,较好的符合Langmuir吸附模型。 与MnFe₂O₄相比其对亚甲基蓝的吸附能力显著增强,室温下pH=9时最大吸附量可以达到29.94 mg/g。 MnFe₂O₄/HA可以作为一种有效去除水体中亚甲基蓝污染物的吸附材料。     

An Adsorption Isotherm from a Micro-state Model

The present study is dedicated to the derivation of an alternative adsorption isotherm for liquid-solid interfaces from a micro-state model, where adsorption is predominantly of a chemical nature. We describe adsorption-desorption on a liquid-solid interface starting from a partition function. In the new model the surface site occupation number is controlled by the Pauli principle (monolayer condition) and additional an attractive or repulsive surface potential, which depends on the overall surface coverage (nonlinearity). The effective potential represents adsorbate adsorbent interaction, as well as an influence of adsorbate adsorbate interactions on the surface potential. A Langmuir equivalent isotherm is recovered in the limit of a weak potential. The proposed model and Langmuirs isotherm are compared using data of humic acid (HA) adsorption on Brazilian Oxisol soil samples. Both models parameterize the experimental data well, but only the new model seems to be self-consistent.     

土壤腐殖质各组分红外光谱研究

土壤腐殖质是土壤中所特有的一类特殊的高分子化合物,具有重要的肥力和环境调节功能。其中胡敏素的提取和纯化很困难,从而限制了对其性质和结构的研究。为揭示胡敏素的结构性质,本研究按Pallo分组,将胡敏酸(HA)分为焦磷酸钠提取的胡敏酸(HAP)、氢氧化钠提取的胡敏酸(HAS);富里酸(FA)分为焦磷酸钠提取的富里酸(FAP)和氢氧化钠提取的富里酸(FAS);胡敏素(HM)分为铁结合胡敏素(HMi)、粘粒结合胡敏素(HMc)和不溶性胡敏素(HMr)三个组分,采用红外光谱法对黑土、草甸土以及黑土底土加入大量玉米秸秆培养后腐殖质各组分的结构特征进行研究。腐殖质各组分按Pallo法分组。结果表明:铁结合胡敏素(HMi)、粘粒结合胡敏素(HMc)与胡敏酸(HA)、富里酸(FA)具有相似的光谱特征,但存在明显差异。黑土、草甸土中HMi和HMc的脂族性强于HA和FA;HMi与HMc相比,HMi具有较高的脂族性。黑土中氢氧化钠提取的胡敏酸(HAS)的脂族性强于焦磷酸钠提取的胡敏酸(HAP);NaOH提取的富里酸(FAS)的脂族性强于Na4P2O7提取的富里酸(FAP)。草甸土中HAP的脂族结构较多,而HAS脂族结构相对较少。在培养土中,新形成的FA脂族性强于HA、HMi和HMc组分。新形成的HMc脂族性强于HMi和HMc的脂族性强于HAP,而弱于HAS。     

Green Template-Mediated Synthesis of Biowaste Nano-Hydroxyapatite: A Systematic Literature Review

Hydroxyapatite (HA) is a well-known calcium phosphate ingredient comparable to human bone tissue. HA has exciting applications in many fields, especially biomedical applications, such as drug delivery, osteogenesis, and dental implants. Unfortunately, hydroxyapatite-based nanomaterials are synthesized by conventional methods using reagents that are not environmentally friendly and are expensive. Therefore, extensive efforts have been made to establish a simple, efficient, and green method to form nano-hydroxyapatite (NHA) biofunctional materials with significant biocompatibility, bioactivity, and mechanical strength. Several types of biowaste have proven to be a source of calcium in forming HA, including using chicken eggshells, fish bones, and beef bones. This systematic literature review discusses the possibility of replacing synthetic chemical reagents, synthetic pathways, and toxic capping agents with a green template to synthesize NHA. This review also shed insight on the simple green manufacture of NHA with controlled shape and size.     

纳米TiO_2对水中腐殖酸的吸附及光催化降解

研究了水体中腐殖酸 ( HA)在纳米 Ti O2 颗粒上的吸附行为 ,并探讨了其吸附机理 ,还研究了 HA的Ti O2 光催化降解效果 .结果表明 ,Ti O2 对 HA的吸附作用明显依赖于水溶液的 p H,也取决于 Ti O2 的零电荷点 ;HA的光催化降解效果与其在催化剂表面的吸附行为密切相关 ,提高吸附速率 ,HA的去除率也随之提高 ;增加催化剂用量也能改善降解程度     

Adsorption of Eu(III) on titanate nanotubes studied by a combination of batch and EXAFS technique

The effects of pH,contact time and natural organic ligands on radionuclide Eu(Ⅲ) adsorption and mechanism on titanate nanotubes(TNTs) are studied by a combination of batch and extended X-ray absorption fine structure(EXAFS) techniques.Macroscopic measurements show that the adsorption is ionic strength dependent at pH < 6.0,but ionic strength independent at pH > 6.0.The presence of humic acid(HA) /fulvic acid(FA) increases Eu(Ⅲ) adsorption on TNTs at low pH,but reduces Eu(Ⅲ) adsorption at high pH.The results of EXAFS analysis indicate that Eu(Ⅲ) adsorption on TNTs is dominated by outer-sphere surface complexation at pH < 6.0,whereas by inner-sphere surface complexation at pH > 6.0.At pH < 6.0,Eu(Ⅲ) consists of ～ 9 O atoms at REu?O ≈ 2.40  in the first coordination sphere,and a decrease in NEu-O with increasing pH indicates the introduction of more asymmetry in the first sphere of adsorbed Eu(Ⅲ).At long contact time or high pH values,the Eu(Ⅲ) consists of ～2 Eu at REu-Eu ≈ 3.60  and ～ 1 Ti at REu-Ti ≈ 4.40 ,indicating the formation of inner-sphere surface complexation,surface precipitation or surface polymers.Surface adsorbed HA/FA on TNTs modifies the species of adsorbed Eu(Ⅲ) as well as the local atomic structures of adsorbed Eu(Ⅲ) on HA/FA-TNT hybrids.Adsorbed Eu(Ⅲ) on HA/FA-TNT hybrids forms both ligand-bridging ternary surface complexes(Eu-HA/FA-TNTs) as well as surface complexes in which Eu(Ⅲ) remains directly bound to TNT surface hydroxyl groups(i.e.,binary Eu-TNTs or Eu-bridging ternary surface complexes(HA/FA-Eu-TNTs)).The findings in this work are important to describe Eu(Ⅲ) interaction with nanomaterials at molecular level and will help to improve the understanding of Eu(Ⅲ) physicochemical behavior in the natural environment.