聚（丙烯酰胺-丙烯酸钠）复合膨润土制备及其对Pb2+的吸附

由溶液聚合法制备了聚(丙烯酰胺-丙烯酸钠)复合膨润土吸附剂,通过FT-IR、XRD、TG-DTG、比表面积和SEM对复合物结构进行了表征。结果表明,丙烯酰胺和丙烯酸钠与膨润土发生插层聚合反应,形成了致密和热稳定性较好的层状复合物。聚(丙烯酰胺-丙烯酸钠)复合膨润土具有—COO-基团与膨润土层间阳离子及Si—OH、Al—OH基团的络合作用要强于聚丙烯酰胺复合膨润土,易于络合溶液中的阳离子。聚丙烯酰胺-丙烯酸钠复合膨润土通过离子交换和络合吸附Pb2+,吸附过程符合Langmuir等温吸附模型和二级动力学吸附模型,平衡吸附量为112.74mg/g。     

果蔬运输包装纸模托盘调湿功能的研究

本文采用向制造果蔬运输包装托盘的纸浆中加入调湿剂,以研究其对纸浆模塑果蔬托盘调湿性能的改善。所选用的调湿剂分别为硅藻土和膨润土。实验在模拟果蔬包装环境内湿度骤然变化的情况下,检验了上述调湿剂对纸模果蔬托盘调湿性能的改善作用,并检测了加入调湿剂后纸模的边压强度。实验结果表明,加入膨润土对纸模调湿性能的改善作用较强,加入两种调湿剂后,纸模的边压强度均有所提高。较佳的膨润土加入量是40％（对总质量）,此时相对空白样,纸模的吸湿和放湿性能提高较明显,可控制环境相对湿度少变化7个百分点（吸湿）和8个百分点（放湿）,边压强度提高0．29×10^3N／m。     

粒状聚(丙烯酸-丙烯酸钠)钙基复合膨润土的制备与吸附性能

用悬浮乳液法以膨润土为主要原料,丙烯酸为聚合单体,司班80(Span 80)作为分散剂,环己烷为分散介质,过硫酸钾为引发剂,N,N-亚甲基双丙烯酰胺为交联剂制备了粒状聚(丙烯酸-丙烯酸钠)钙基复合膨润土吸附剂。以丙烯酸(钠)单体溶出量和Cd2+吸附量为目标函数,对粒状复合膨润土制备进行单因素优化实验,确定适宜合成条件为聚合温度70℃、聚合时间3 h、有机相环己烷与司班80(Span 80)体积比52.5∶2.5、油水比100∶15,其中水相为膨润土、丙烯酸、氢氧化钠与水的混合物。通过X射线衍射、红外光谱和扫描电镜对产品进行表征分析,对共聚反应机理进行了讨论。结果表明:粒状复合膨润土制备过程中,丙烯酸和丙烯酸钠插层进入到膨润土层间,在层间发生了聚合反应,并且没有破坏原土的基本结构。复合膨润土对Pb2+、Cd2+、F-吸附性能优于钙基膨润土。     

温敏互穿网络水凝胶/改性膨润土复合吸水保水材料的制备及表征

以改性膨润土、2-丙烯酰胺基-2-甲基丙磺酸、丙烯酰胺和新型温敏大分子单体为主要原料,N, N′-亚甲基双丙烯酰胺为交联剂,采用水溶液互穿网络聚合技术制备了温敏互穿网络水凝胶/改性膨润土复合吸水保水材料。利用X射线衍射仪(XRD)、傅里叶变换红外光谱仪(FTIR)、热重分析仪(TG)、扫描电子显微镜(SEM)和差示扫描量热仪(DSC)对样品进行了表征分析。考察了复合吸水保水材料的溶胀性能、温度敏感性能、去溶胀性能、振荡溶胀-去溶胀性能和拉伸性能。结果表明,20℃时复合吸水保水材料DNB5在蒸馏水和0.9%(质量分数)NaCl溶液中的最大溶胀率分别为20.59 g/g和7.92 g/g;随着改性膨润土或第二网络结构中丙烯酰胺(AM)含量的增加,复合吸水保水材料的低临界溶解温度(LCST)、溶胀率和拉伸强度增加,表现出良好的吸水、保水和温敏性;复合吸水保水材料呈现可逆溶胀-去溶胀行为和较好的机械强度。     

CTAB/聚合物复合插层膨润土降滤失剂的制备与表征

以膨润土为原料,十六烷基三甲基溴化铵、单体丙烯酰胺和2-丙烯酰胺基-2-甲基丙磺酸为插层剂,通过离子交换法,在过硫酸钾的引发下,合成了一种新型的复合材料P(AMPS-AM)/CTAB/Na-T,并对其结构进行了红外光谱(FT-IR)、X射线衍射(XRD)和电子扫描电镜(SEM)表征.考察了单体配比、十六烷基三甲基溴化铵的加量以及膨润土加量对该复合材料降滤失量的影响.实验结果表明,在丙烯酰胺和2-丙烯酰胺基-2-甲基丙磺酸的比为6∶1,十六烷基三甲基溴化铵的加量为5%,膨润土加量为15%时该复合材料的性能最好;检测结果显示,膨润土表面的羟基参与了反应,P(AMPS-AM)/CTAB进入到膨润土夹层,其层间距增大了0.711nm,而改性前后膨润土的形貌并没有发生大的变化.     

无N2下合成钠基膨润土/P(AA-AM)复合吸水树脂的研制

以N,N'-亚甲基双丙烯酰胺为交联剂,过硫酸钾为引发剂,丙烯酸(AA)和丙烯酰胺(AM)为单体,采用水溶液聚合法合成出钠基膨润土复合聚丙烯酸钠-丙烯酰胺复合吸水树脂.研究了钠基膨润土的添加量、交联剂用量、引发剂用量、中和度及AM的用量对吸水倍率的影响.结果表明,钠基膨润土用量为40%,交联剂用量为0.025%,引发剂用量为0.3%,AM用量为12%及AA的中和度为80%时,吸蒸馏水倍率与吸收0.7%NaCl溶液倍率分别为422.28 g/g和65.80 g/g.     

钠基膨润土-AM-AA共聚复合型净水剂的制备及表征

为了改善膨润土的吸附性能和使用性能,文中以钠基膨润土为主体原料,进行了丙烯酰胺(AM)和丙烯酸(AA)聚合制备钠基膨润土-聚丙烯酰胺-聚丙烯酸复合物的研究,并通过对产品和原料进行X射线衍射(XRD)、红外光谱(FT-IR)、扫描电镜(SEM)和热重表征等表征分析,探讨了聚合机理。结果表明,丙烯酰胺和丙烯酸插层进入膨润土层间,在层间发生了聚合反应,所制备的复合物呈现类似吸水树脂的物理形态,在水中不发生解离。复合新型净水剂对Pb2+离子的吸附性能随着膨润土含量的提高而增加,且明显优于钠基膨润土。     

复合调湿材料的研究进展

在简要介绍调湿材料的概念、工作原理、分类和调湿机理,及分析单一调湿材料优缺点的基础上,阐述了发展复合调湿材料的必要性,并归纳总结了复合调湿材料的种类、制备方法、调湿特性和机理.最后指出了复合调湿材料的发展前景、应用领域和研究方向.     

高性能木质素基重金属离子吸附凝胶的制备

以木质素磺酸钠(LS-Na)、丙烯酰胺(AM)、马来酸酐(MAH)为原料,膨润土(Bentonite)为无机添加剂,过硫酸钾(KPS)为引发剂,N,N-亚甲基双丙烯酰胺(NMBA)为交联剂,采用溶液接枝共聚合法制备了两种木质素基重金属离子吸附凝胶:膨润土/木质素磺酸钠接枝丙烯酰胺(BLPAM)、膨润土/木质素磺酸钠接枝丙烯酰胺马来酸酐(BLPAMA),研究了不同后处理方式对于两种凝胶吸附性能的影响。结果表明,BLPAM皂化产物具有很好的重金属离子吸附容量和去除率;BLPAMA皂化产物具有很高的Pb2+选择性。     

淀粉/膨润土复合高吸水树脂的制备工艺研究

以淀粉、膨润土、丙烯酸、丙烯酰胺等为原料,采用微波辐射法制备复合高吸水树脂。研究了膨润土用量、丙烯酰胺用量、引发剂用量、交联剂用量等对高吸水树脂吸液率性能的影响。实验结果表明,不同比例下的原材料制得的树脂吸水倍率差异很大。在交联剂为0.045%,引发剂0.32%,中和度70%,膨润土10%,磷酸酯淀粉3%,丙烯酸与丙烯酰胺质量比为2∶1,微波功率为800W辐射15min时吸蒸馏水倍率为796g/g,当丙烯酸与丙烯酰胺质量比为1∶1时,吸0.9%NaCl溶液倍率达95g/g。     

Adsorption characteristics of UO(2)(2+) and Th(4+) ions from simulated radioactive solutions onto chitosan/clinoptilolite sorbents

Adsorption features of UO(2)(2+) and Th(4+) ions from simulated radioactive solutions onto a novel chitosan/clinoptilolite (CS/CPL) composite as beads have been investigated compared with chitosan cross-linked with epichlorohydrin. The effects of contact time, the initial metal ion concentration, sorbent mass and temperature on the adsorption capacity of the CS-based sorbents were investigated. The adsorption kinetics was well described by the pseudo-second order equation, and the adsorption isotherms were better fitted by the Sips model. The maximum experimental adsorption capacities were 328.32 mg Th(4+)/g composite, and 408.62 mg UO(2)(2+)/g composite. The overall adsorption tendency of CS/CPL composite toward UO(2)(2+) and Th(4+) radiocations in the presence of Cu(2+), Fe(2+) and Al(3+), under competitive conditions, followed the order: Cu(2+)>UO(2)(2+)>Fe(2+)>Al(3+), and Cu(2+)>Th(4+)>Fe(2+)>Al(3+), respectively. The negative values of Gibbs free energy of adsorption indicated the spontaneity of the adsorption of radioactive ions on both the CS/CPL composite and the cross-linked CS. The desorption level of UO(2)(2+) from the composite CS/CPL, by using 0.1M Na(2)CO(3), was around 92%, and that of Th(4+) ions, performed by 0.1M HCl, was around 85%, both values being higher than the desorption level of radiocations from the cross-linked CS, which were 89% and 83%, respectively.     

Factors influencing the removal of divalent cations by hydroxyapatite

The effect of pH, contact time, initial metal concentration and presence of common competing cations, on hydroxyapatite (HAP) sorption properties towards Pb(2+), Cd(2+), Zn(2+), and Sr(2+) ions was studied and compared using a batch technique. The results strongly indicated the difference between the sorption mechanism of Pb(2+) and other investigated cations: the removal of Pb(2+) was pH-independent and almost complete in the entire pH range (3-12), while the sorption of Cd(2+), Zn(2+) and Sr(2+) generally increased with an increase of pH; the contact time required for attaining equilibrium was 30 min for Pb(2+) versus 24h needed for other cations; maximum sorption capacity of HAP sample was found to be an order of magnitude higher for Pb(2+) (3.263 mmol/g), than for Cd(2+) (0.601 mmol/g), Zn(2+) (0.574 mmol/g) and Sr(2+) (0.257 mmol/g); the selectivity of HAP was found to decrease in the order Pb(2+)>Cd(2+)>Zn(2+)>Sr(2+) while a decrease of pH(PZC), in respect to the value obtained in inert electrolyte, followed the order Cd(2+)>Zn(2+)>Pb(2+)>Sr(2+); neither of investigated competing cations (Ca(2+), Mg(2+), Na(+) and K(+)) influenced Pb(2+) immobilization whereas the sorption of other cations was reduced in the presence of Ca(2+), in the order Sr(2+)>Cd(2+)>or=Zn(2+). The pseudo-second order kinetic model and Langmuir isotherm have been proposed for modeling kinetic and equilibrium data, respectively. The sorption of all examined metals was followed by Ca(2+) release from the HAP crystal lattice and pH decrease. The ion exchange and specific cation sorption mechanisms were anticipated for Cd(2+), Zn(2+) and Sr(2+), while dissolution of HAP followed by precipitation of hydroxypyromorphite (Pb(10)(PO(4))(6)(OH)(2)) was found to be the main operating mechanism for Pb(2+) immobilization by HAP, with the contribution of specific cation sorption.     

红外上转换纳米发光材料的水热合成

利用稀土离子Y~(3+)、Yb~(3+)、Er~(3+)与乙二胺四乙酸形成的配合物,加入可溶性氟化物.控制溶液的pH值,利用配位-沉淀平衡体系制备了复合氟化物纳米粒子前驱物,在240℃下水热晶化前驱物,合成了红外上转换纳米发光材料.     

Removal of mixed heavy metal ions in wastewater by zeolite 4A and residual products from recycled coal fly ash

The removal performance and the selectivity sequence of mixed metal ions (Co(2+), Cr(3+), Cu(2+), Zn(2+) and Ni(2+)) in aqueous solution were investigated by adsorption process on pure and chamfered-edge zeolite 4A prepared from coal fly ash (CFA), commercial grade zeolite 4A and the residual products recycled from CFA. The pure zeolite 4A (prepared from CFA) was synthesized under a novel temperature step-change method with reduced synthesis time. Batch method was employed to study the influential parameters such as initial metal ions concentration, adsorbent dose, contact time and initial pH of the solution on the adsorption process. The experimental data were well fitted by the pseudo-second-order kinetics model (for Co(2+), Cr(3+), Cu(2+) and Zn(2+) ions) and the pseudo-first-order kinetics model (for Ni(2+) ions). The equilibrium data were well fitted by the Langmuir model and showed the affinity order: Cu(2+) > Cr(3+) > Zn(2+) > Co(2+) > Ni(2+) (CFA prepared and commercial grade zeolite 4A). The adsorption process was found to be pH and concentration dependent. The sorption rate and sorption capacity of metal ions could be significantly improved by increasing pH value. The removal mechanism of metal ions was by adsorption and ion exchange processes. Compared to commercial grade zeolite 4A, the CFA prepared adsorbents could be alternative materials for the treatment of wastewater.     

Biosorption of heavy metal ions on immobilized white-rot fungus Trametes versicolor

Trametes versicolor mycelia were immobilized in carboxymethylcellulose, CMC, beads via entrapment, and the bead containing immobilized fungus spores were incubated at 30 degrees C for 3 days to attain uniform growth on the bead surface. After incubation, the live and heat inactivated immobilized fungus on the CMC beads were used for the biosorption of Cu(2+), Pb(2+) and Zn(2+) ions.Plain CMC beads were used as a control system. The biosorption of Cu(2+), Pb(2+) and Zn(2+) ions by the CMC and both live and inactivated immobilized preparations increased as the initial concentration of Cu(2+), Pb(2+) and Zn(2+) ions in the medium increased. The maximum biosorption capacities for both immobilized live and heat inactivated Trametes versicolor were 1.51 and 1.84mmol Cu(2+), 0.85 and 1.11mmol Pb(2+) and 1.33 and 1.67mmol Zn(2+) per g of dry biosorbents, respectively. Biosorption equilibrium was established in about 1.0h and the equilibrium was well described by Langmuir and Freundlich isotherms. A temperature change in the range of 15-45 degrees C did not affect the biosorption capacity. The affect of pH was also investigated and the maximum adsorption of Cu(2+), Pb(2+) and Zn(2+) ions on the CMC and both live and inactivated immobilized fungal biomass was observed between pH 4.0 and 6.0. The CMC beads with the immobilized fungus can be regenerated using 10mM HCl, with up to 97% recovery of the metal ions; the biosorbents reused up to five biosorption-desorption cycles without any major loss in the biosorption capacity.     

燃烧法合成SrZnO_2:Eu~(3+),Li~+及荧光性能

采用燃烧法合成了SrZnO2:Eu3+,Li+发光材料,用X射线衍射谱、荧光光谱对样品进行了表征。结果表明,Eu3+和Li+成功掺入SrZnO2基质中,Eu3+离子在基质中主要占据Sr2+离子不对称性格位,发射来源于5D0→7F2615nm为主的红光。加入电荷补偿剂Li+离子的掺入能显著提高发光强度,其影响程度与Eu3+、离子和Li+离子的掺杂比例密切相关。     

高分子网络凝胶法制备YAG:Er~(3+)纳米晶粉体及其光谱性质

采用高分子网络凝胶法,在较低温度下制备了YAG:Er~(3+)纳米晶粉体.分别用热重-差热分析(TG-DSC)、X射线衍射(XRD)、扫描电子显微镜(SEM)以及激发和发射光谱对样品进行了表征.结果表明:石榴石晶相的形成温度为880℃,与YAG纳米晶粉体相比,用Er~(3+)代替Y~(3+)后,YAG:Er~(3+)纳米晶粉体还是以石榴石晶相为主,未发生明显变化;YAG:Er3~(3+)纳米晶粉体有丰富的吸收谱线,并且在260nm激发光激发下YAG:Er~(3+)纳米晶粉体可以发射出377nm紫光,可以作为紫光光源的考虑对象.     

SiN_x:Tb~(3+)薄膜中Tb~(3+)与银表面等离激元耦合

本文采用PECVD方法在石英衬底上生长不同剂量比的氮化硅薄膜SiNx,并利用离子注入方法在SiNx中注入Tb3+离子。然后通过在SiNx薄膜表面沉积银岛膜,研究了银表面等离激元和SiNx:Tb3+发光的相互作用。研究发现,银岛膜的存在降低了SiNx:Tb3+发光荧光寿命,而且SiNx:Tb3+发光荧光寿命随着银岛膜厚度的增加而减小。而氮化硅薄膜中的硅纳米晶也会影响Tb3+的光模密度,并对SiNx:Tb3+发光荧光寿命产生影响。     

真空紫外光激发下Tb~(3+)激活的稀土正硼酸盐的发光

报导了Tb3+、Ce3+激活的稀土正硼酸盐的真空紫外光谱。分析了Ce3+的4f75d能级随基质结构、基质阳离子的变化,讨论了温度、Tb3＋离子的浓度对发光的影响以及Ce3＋－Tb3＋间的能量传递.     

掺杂锗酸铋晶体(Bi_4Ge_3O_(12))的电子顺磁共振

用电子顺磁共振方法对 Fe、Cr 和 Mn 杂质在 Bi_4Ge_3O_(12)晶体中的位置和价态进行了研究。测试并分析了和 Fe~(3+)和 Cr~(3+)离子的 EPR 谱线位置随磁场方向的变化,确定了 Fe~(3+)和 Cr~(3+)主要进入氧四面体占据 Ge位。测试并分析了 Mn~(4+)和Mn~(2+)掺杂样品各向异性的 EPR 谱线,也测试了处于晶体粉末态及玻璃态的 Mn 掺杂样品的谱线,认为 Mn~(2+)离子进入氧八面体占据 Bi 位。紫外线辐照后 Mn 离子 EPR 信号降低表明辐照导致 Mn 离子价态改变。