改性纳米二氧化硅的制备及其对亚甲基蓝的吸附性能

以溶胶凝胶、原位修饰法制备偶联剂KH550表面修饰纳米二氧化硅作为新型吸附剂,对吸附剂进行FTIR、SEM、TG等分析表征。探讨了新型吸附剂对阳离子染料亚甲基蓝模拟废水进行吸附处理,研究了pH、离子强度、温度对亚甲基蓝吸附性能的影响及吸附机理。改性纳米二氧化硅吸附染料的p H应用范围较宽。NaCl浓度对染料吸附有较大的影响,浓度增大,亚甲基蓝吸附容量增大。温度升高,亚甲基蓝吸附容量因脱附有所下降。改性纳米二氧化硅吸附亚甲基蓝符合Langmuir吸附模型,最大吸附容量为17.7mg·g~(-1),为优惠吸附。改性纳米二氧化硅经五次再生后,可重复利用吸附亚甲基蓝,吸附量基本不变。     

花生壳纤维素的制备及其对水中亚甲基蓝吸附的研究

本文以废花生壳为原料制备了花生壳纤维素并将其用于去除水中亚甲基蓝染料。系统考察了溶液的p H值,亚甲基蓝的初始浓度,吸附时间,吸附温度以及溶液离子强度对亚甲基蓝吸附性能的影响。结果表明:pH=9时,花生壳纤维素对亚甲基蓝的吸附效果最佳,饱和吸附容量q_m为156.2 mg·g~(-1);吸附热力学研究表明,吸附过程符合Langmuir等温吸附模型。吸附过程焓变ΔH为-44.74 k J·mol~(-1),ΔS为-137.9 J·mol~(-1)·K~(-1),ΔG0,表明花生壳纤维素对亚甲基蓝的吸附过程是自发的放热过程;吸附过程可在20 min内达到平衡,符合准二级动力学模型;其吸附过程的活化能Ea=82.6 k J·mol~(-1)。吸附容量随着溶液离子强度的增大而减小,说明其吸附是以静电作用为主的吸附过程。10次循环使用后花生壳纤维素对亚甲基蓝的吸附效率仍能保持88%以上,表明该材料可以多次循环使用。     

ZnO/C纳米球的亚甲基蓝单吸附特性:平衡、动力学及机理（英文）

采用电弧放电法制备了Zn O/C纳米球,利用FESEM、XRD和N2吸附/脱附测试进行了表征。在避光条件下研究了复合材料对亚甲基蓝的吸附性能。研究结果表明,随着亚甲基蓝的浓度及接触时间的增长吸附量明显上升,在吸附时间为150 min时达到吸附平衡。采用Langmuir、Freundlich及Temkin等温吸附模式对吸附平衡进行了研究。结果表明,吸附等温线符合Langmuir等温吸附模式,单层吸附饱和容量可达188.68 mg·g-1。利用动力学模型、内扩散模型和外扩散速率控制模型拟合实验数据,拟合数据表明其动力学符合伪二级动力学模型;内扩散机理不是吸附速率的唯一限制机理,亚甲基蓝的总吸附速率受膜扩散控制。     

明胶改性磁性石墨烯对亚甲基蓝的吸附性能研究

采用化学还原法制备了一种新型的明胶掺杂磁性石墨烯复合材料(gelatinMGO),并进一步研究了pH值、接触时间和温度对该材料吸附亚甲基蓝的影响。亚甲基蓝吸附实验结果表明,gelatin-MGO对亚甲基蓝有较大的吸附能力,最大吸附容量可达210.5mg/g,吸附为自发吸热过程,在pH值为6.5时去除率最大,其吸附过程符合拟二级反应动力学方程和Langmuir吸附模型,解吸实验表明,明胶改性石墨烯的再生性能优异,重复使用5次去除率仍为85%以上,该材料适合作为吸附剂去除废水中的亚甲基蓝。     

活化赤泥对染料废水吸附性能研究

以赤泥为原料,十二烷基苯磺酸钠为活化剂,制备出活化赤泥吸附剂,并对亚甲基蓝(MB)染料废水吸附性能进行研究。结果表明,活化赤泥对亚甲基蓝的吸附效果有一定提高。振荡时间15min,活化赤泥6g·L~(-1),中性条件下,对40mg·L~(-1)亚甲基蓝吸附率可达90%。吸附符合Langmuir和Freundlich吸附等式,最大吸附量为16.37mg·g~(-1)。活化赤泥吸附亚甲基蓝为放热反应,低温利于亚甲基蓝吸附。     

多硅酸改性石墨烯及其吸附性能的研究

通过多硅酸改性石墨烯合成惰性物质改性的石墨烯基吸附剂,研究了改性石墨烯的官能团与成分。进行氮气吸附脱附测试,结果表明改性石墨烯的孔径增加。改性石墨烯的吸附性能用亚甲基蓝、甲基橙和腐植酸进行测试,吸附性能提高。改性石墨烯对亚甲基蓝的吸附量达到202.4 mg·g-1,高于石墨烯的吸附量115.9mg·g-1。     

改性埃洛石材料的制备及其对亚甲基蓝吸附行为的研究

使用硅烷偶联剂KH550改性埃洛石纳米管获得改性材料HNTs-APTS,并对其吸附亚甲基蓝的行为进行研究。利用傅立叶变换红外光谱仪(FTIR)、X-衍射仪(XRD)对改性前后的埃洛石进行表征。考察了吸附时间和温度对吸附过程的影响,并采用Lagrange准二级动力学方程、Langmuir等温线方程及Freundlich等温线方程对实验数据进行拟合。结果表明,KH550成功负载到埃洛石表面;改性后材料的吸附能力大大提高。改性埃洛石对亚甲基蓝的吸附约在60 min达平衡,最大吸附容量为21.66 mg/g。其吸附过程符合准二级动力学方程,热力学较好地符合Langmuir等温线方程,且吸附过程为自发吸热,升高温度有利于吸附的进行。改性材料可重复再生6次,具有良好的再生性能,可在工业处理亚甲基蓝废水中使用。     

改性固化单宁对稀土离子Pr3+,Nd3+吸附性能研究

以苎麻纤维为基础,通过甲醛交联固化杨梅单宁制备吸附材料(RF-BT),进一步经Mannich反应改性,引入-NH2,制备改性苎麻纤维接枝杨梅单宁吸附材料(RF-BTM)。通过IR和SEM等方法表征了两种材料的结构,并研究了两种材料对Pr3+,Nd3+稀土离子的吸附性能。实验结果表明:反应温度为303 K,p H为5.5,Pr3+溶液初始浓度为1127.2 mg·L-1,Nd3+溶液初始浓度为1153.6 mg·L-1时,RF-BT的最大吸附量为:Pr3+420.3 mg·g-1,Nd3+432.8 mg·g-1;RF-BTM的最大吸附量为:Pr3+461.7 mg·g-1,Nd3+477.8 mg·g-1;表现出优良的吸附性能,其吸附热力学符合Freundlich方程,动力学可用拟二级速率方程描述。     

以铬皮为原料制备多孔炭及其对亚甲基蓝的吸附性能研究

以铬皮为原料制备多孔炭,并考察其对亚甲基蓝染料的吸附性能,对其吸附机理进行了探讨。结果表明,体系pH、亚甲基蓝初始浓度和吸附时间对多孔炭吸附亚甲基蓝的能力影响较大。通过吸附等温线和吸附动力学研究,发现该吸附过程可用Langmuir吸附等温线来描述,且符合准二级动力学吸附模型。铬皮基多孔炭有望成为含亚甲基蓝污水处理的良好净化剂。     

改性SiO_2聚合物微球对阳离子染料的吸附行为

本文以3-氨丙基三乙氧基硅烷(KH-550)为改性剂,先在碱性条件下对SiO_2改性得到改性二氧化硅(Poly-SiO_2),再以丙烯酸、丙烯酰胺为单体,N,N′-亚甲基双丙烯酰胺(MBA)为交联剂,采用反相悬浮法对Poly-SiO_2进一步改性,制备了一种改性SiO_2聚合物微球(AA-Poly-SiO_2)。通过傅立叶变换红外光谱、热重分析、扫描电子显微镜、X射线粉末衍射分析其结构特性。考察了AA-Poly-SiO_2对含氮阳离子染料亚甲基蓝、碱性品红、甲基紫、乙基紫的吸附性能,研究了时间、pH、吸附剂用量、初始浓度对吸附染料的影响,以及吸附动力学和等温吸附过程。得到的AA-Poly-SiO_2的平均尺寸为8.20μm,比表面积为0.0725 m~2/g。其等温吸附符合Langmuir模型,吸附过程遵循Langmuir等温吸附和准二级动力学模型,为单层化学吸附。该AA-Poly-SiO_2对乙基紫的最大吸附容量可达1 000 mg/g。与常规聚丙烯酰胺微球相比,AA-Poly-SiO_2显示出更高的吸附容量,可以循环使用5次,吸附率仍在78%以上。     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

Synthesis of pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles by Curtius reaction in Morita-Baylis-Hillman derivatives

Synthesis of substituted pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles from the Morita-Baylis-Hillman derivatives of acrylates via saponification followed by Curtius reaction is described.     

正丁胺对激光染料荧光谱影响的研究

用正丁胺作为碳源,采用射频辉光放电制备碳膜,选用激光染料R6G和聚乙二醇混合液作为蒸气源,采用单源热蒸发,在蒸发室与染料同时沉积得到混合膜,用拉曼光谱和红外光谱分析了碳膜的结构和键合方式,分析表明:碳膜中存在胺基团和氢原子.混合膜的荧光谱测量结果表明,认为正丁胺对染料荧光谱的影响是因为胺基和氢原子的存在.     

Cu0-catalysed 1,3-dipolar cycloadditions of α-amino acid derived N,N-cyclic azomethine imines to ynones

A series of 20 CuAIAC reactions between eight 4-acylamino substituted pyrazolidine-3-one-1-azomethine imines and four terminal ynones were performed using Cu⁰ as catalyst. The corresponding fluorescent cycloadducts were obtained in very high yields upon simple workup. Thus, Cu-metal turned out to be a better catalyst than Cu^I in terms of yield and ease of isolation. Availability of azomethine imines, mild reaction conditions, and simple workup enable a “click” access to libraries of densely substituted 2,3-dihydro-1H,5H-pyrazolo[1,2-a]pyrazol-1-ones. Reactivity of differently substituted dipoles was evaluated experimentally and by quantum chemical methods (DFT).     

Synthesis and antioxidative/anti-inflammatory activity of novel fullerene–polyamine conjugates

(E)-4-(Fullerenopyrrolidin-1-yl)-3-methylbut-2-enoic acid and its corresponding succinimidyl ester, readily obtained through Prato-type modification of C₆₀, were used for the selective N-acylation of polyamines. The thus obtained conjugates were evaluated for their antioxidative and anti-inflammatory activity and their cytotoxicity was determined. Members of this family of compounds showed interesting anti-lipid peroxidation, anti-lipoxygenase and anti-inflammatory activity and comparable cytocompatibility to spermidine.