羊毛/铁配合物非均相芬顿反应光催化剂的制备及其应用性能

为提升废旧羊毛的回收再利用价值,将具有不同直径和鳞片结构的3种羊毛分别与水溶液中Fe³⁺进行配位反应,得到3种羊毛/铁配合物,然后将其作为非均相芬顿反应光催化剂应用于活性红195的氧化降解反应中,研究了反应条件以及羊毛直径和鳞片层等对配合物的铁离子配合量和光催化性能的影响。结果表明:Fe³⁺浓度和配位反应温度的升高均能促进Fe³⁺和羊毛之间配位反应的进行,较薄鳞片层的羊毛更易与Fe³⁺反应,制备更高铁离子配合量的羊毛/铁配合物;可使用Lagergren准二级动力学模型方程对羊毛与Fe³⁺之间的配位反应进行描述,但较薄鳞片层羊毛的反应速度更慢;3种羊毛/铁配合物都可显著催化染料发生氧化降解反应,提高铁离子配合量和辐射光强度,均能增加其光催化性能,较细羊毛制备的配合物具有更强的催化作用和pH值适应性。     

聚苯乙烯/铁-单宁酸配合物微球在棉织物上的结构生色

针对目前基于多巴胺制备结构色织物的过程耗时及成本高的问题,采取单宁酸替代多巴胺快速实现结构色效果,制备了聚苯乙烯/铁-单宁酸配合物(PS/TA-Fe³⁺)微球,并通过重力沉积法在棉织物表面构建无规密堆积的非晶胶体阵列。采用马尔文纳米粒度分析仪、场发射电子显微镜、透射电子显微镜和显微角分辨光谱仪对聚苯乙烯(PS)微球、PS/TA-Fe³⁺微球和结构色织物进行了表征,探究了适宜的单宁酸和Fe³⁺用量,表征了结构色织物表面PS/TA-Fe³⁺微球的排列、结构生色效果及PS/TA-Fe³⁺涂层的结构稳定性。结果表明:当单宁酸用量为10%、单宁酸与Fe³⁺的量比为10:1时,制备的PS/TA-Fe³⁺微球粒径均匀、单分散性较好,结构色织物颜色柔和明亮,不具备角度依赖性,且具有良好的耐洗涤和耐摩擦性能。     

脉冲放电等离子体制备壳聚糖铁(Ⅲ)配合物及结构表征

以壳聚糖浓度、Fe3+浓度、极板间距和处理时间为影响因素,采用脉冲放电等离子体法制备壳聚糖(CTS)铁(Ⅲ)配合物。并利用红外光谱法(FT-IR)和紫外光谱(UV)进行结构表征。实验结果表明,脉冲放电等离子体可以用来制备CTS-Fe3+配合物,Fe3+浓度、处理时间与吸附量成正相关关系,随影响因素值增大,吸附量增大;壳聚糖浓度、极板间距成负相关关系,随影响因素值降低,吸附量减少。壳聚糖与铁(Ⅲ)发生配位作用的基团可能是-NH2和-COOH。     

造纸污泥基纳米复合材料的制备及其对废水中重金属的吸附

利用造纸污泥与壳聚糖制备造纸污泥-壳聚糖(SL-CSA)纳米复合吸附材料,研究了SL-CSA纳米复合材料对废水中铬离子(Cd²⁺)和铅离子(Pb2+)的吸附性能。通过傅里叶变换红外光谱仪(FT-IR)和扫描电子显微镜(SEM)表征证明了复合材料的成功制备。吸附实验表明,SL-CSA纳米复合材料对Cd²⁺和Pb²⁺的吸附均遵循准二级动力学方程,属于化学吸附。根据Langmuir模型,SL-CSA纳米复合材料对Cd²⁺和Pb2+的最大吸附量分别为314.05 mg/g和320.06 mg/g。     

金属-多酚网络/纤维素微纤丝复合物的制备及其抗氧化性和稳定性研究

利用Fe³⁺和单宁酸(TA)制备金属-多酚网络(MPN),并用于纤维素微纤丝(CMF)的功能化改性,以制备CMF-MPN复合物,探讨CMF与MPN制备条件对CMF-MPN复合物抗氧化性和稳定性等的影响。结果表明,MPN可赋予CMF抗氧化性,当TA与Fe³⁺质量比为4∶1、pH值为3制备的MPN添加量为2%(相对于绝干CMF质量)时,所得CMF-MPN复合物的DPPH清除率达97.0%;热重分析结果表明,CMF-MPN复合物残余质量相对于CMF提高了8.13%,但最大热降解温度略有下降;傅里叶变换红外光谱分析结果表明,CMF与MPN间的吸附为物理吸附;以CMF为载体可以提高MPN结构的稳定性,放置60天后仍能保持初始抗氧化性的80%左右,具有缓慢持续释放抗氧化因子的性能,这为开发绿色食品保鲜包装材料提供了新思路。     

木质素磺酸盐-壳聚糖吸附剂的制备及其对Cu2+和Co2+的吸附性能

针对现有吸附剂合成成本高、制备工艺复杂以及吸附性能差,以丙烯酸、木质素磺酸盐和壳聚糖为原料,利用自由基聚合法制备了一种新型的木质素磺酸盐/壳聚糖多孔吸附剂(即CSL吸附剂)。通过SEM、FT-IR以及TGA等手段对CSL吸附剂的形貌、结构及热性能进行观察与表征分析,并研究了CSL吸附剂对Cu²⁺和Co²⁺的吸附效果。结果表明：CSL吸附剂能有效吸附水溶液中的重金属离子,对Cu²⁺和Co²⁺的去除效果良好。利用CSL吸附剂处理Cu²⁺、Co²⁺是一种绿色环保的方法。     

零价铁/氧化石墨烯复合吸附剂对染料和重金属的吸附性能

针对目前酸性染料染色废水中染料和重金属Cr(Ⅵ)引起的严重环境污染问题,以零价铁(Fe⁰)/氧化石墨烯(GO)复合物作为吸附剂,以分别含有弱酸性蓝AS和Cr(Ⅵ)的水溶液模拟染色废水,探究Fe⁰与GO的质量比、溶液pH值及染料与Cr(Ⅵ)的初始质量浓度对吸附性能的影响,考察Fe⁰/GO吸附剂对酸性染料与Cr(Ⅵ)的吸附机制,研究其吸附热力学与动力学。结果表明：Fe⁰与GO吸附剂在质量比为4∶1时具有最佳吸附效果,弱酸性蓝AS染液初始质量浓度为75 mg/L,温度为30℃,pH值为4.0时,12 h后去除率为85.6%,最大吸附量达到85.6 mg/g; Cr(Ⅵ)溶液初始质量浓度为75 mg/L,温度为30℃,pH值为3.0时,12 h后去除率为95.8%,最大吸附量达到95.8 mg/g; Fe⁰/GO对2种污染物的吸附过程均符合Langmuir模型和准二级动力学模型。     

酪蛋白胶束对原花青素稳定性的影响

以酪蛋白胶束(micellar casein, MC)为基质，原花青素(proanthocyanidin, PCs)为配体，制备PCs-MC复合物，采用紫外-可见光谱、荧光光谱、傅里叶变换红外光谱等手段表征复合物结构，研究不同温度(4、37、50、65℃)、不同金属离子(Fe³⁺、Zn²⁺)、不同H₂O₂含量(0.006%、0.024%,体积分数)和超声处理下MC对PCs稳定性的影响。结果显示，PCs对MC有荧光猝灭作用，二者以疏水作用形成复合物。MC提高了PCs在37、50、65℃处理下的保留率，改善了其在H₂O₂存在下的稳定性。然而，在4℃贮藏时，MC促进了PCs的降解，且当Fe³⁺和Zn²⁺存在时，MC降低了PCs的稳定性。超声处理下，PCs-MC复合物中PCs保留率低于游离PCs。可见，MC有利于提升PCs热稳定性和氧化稳定性，但不利于改善其金属离子稳定性。     

普洱茶-硒掺杂碳量子点和单质硒的同时制备及其在Fe3+检测中的应用

目的:为探讨普洱茶-纳米硒制备掺杂型碳量子点的可行性及其相关特性,实现水体系中Fe³⁺的快速检测。方法:以普洱茶水提取物稳定分散的普洱茶-硒原子为掺杂原子,采用水浴法,通过优化反应温度和时间,同时制备出普洱茶-硒掺杂碳量子点(Pu-erh tea nano-selenium doped carbon quantum dots,PT-Se-CQDs)和单质硒两种物质;采用紫外-可见吸收光谱和荧光光谱等技术表征PT-Se-CQDs的紫外-可见吸收特性和荧光强度,采用透射电子显微镜、X射线光电子能谱及X射线衍射等技术表征其形态形貌、元素组成及结构特性;并以PT-Se-CQDs为荧光探针构建荧光传感器,用于水体系中Fe³⁺检测。结果:当反应温度100℃、反应时间10 h时,可同时制备得量子产率为3.41%、平均直径约为3.1 nm的类球形PT-Se-CQDs和单质硒。Fe³⁺对PT-Se-CQDs具有强荧光静态猝灭效应,当Fe³⁺浓度为0～300μmol/L时,比率荧光强度(F/F₀)...     

氧化石墨烯/罗丹明6G改性滤纸的制备及性能

利用氧化石墨烯(GO)和罗丹明6G-聚乙烯亚胺(R6G-PEI)对滤纸(FP)进行物理改性,制备了纸基传感器FP/GO/R6G-PEI。利用扫描电子显微镜、X-射线衍射仪、伺服材料多功能高低温控制试验机、紫外光谱仪和荧光光谱仪等,对FP/GO/R6G-PEI的形貌、力学性能和传感性能进行表征。结果表明,与FP、FP/GO相比,FP/GO/R6G-PEI的表面平滑度提高,透气度降低,力学性能增大。将FP/GO/R6G-PEI浸泡于Fe³⁺溶液中时,观察到FP/GO/R6G-PEI变为淡粉红色,且荧光强度显著增强,可实现FP/GO/R6G-PEI对水中的Fe³⁺肉眼可见和荧光检测。理想识别单元Structure 3与Fe³⁺的能级差(0.53 eV)小于Structure 3的能极差(3.12 eV),说明Structure 3与Fe³⁺的螯合体系更稳定。     

聚苯胺/壳聚糖/羊毛复合织物导电性能及苯胺吸附分子模拟

为提高聚苯胺/ 羊毛复合织物的导电性能,采用原位聚合法利用醋酸和盐酸共掺杂一步合成聚苯胺/ 壳聚糖(PANI/ CTS) / 羊毛复合导电织物。借助场发射扫描电镜、X 射线光电子能谱仪和四探针测试仪对复合织物的结构和导电性能进行分析,研究了CTS 用量对复合织物导电性能的影响。采用分子模拟方法模拟苯胺吸附的微观运动,进一步研究了CTS 增强PANI/ 羊毛复合织物导电性能的微观机制。结果表明：当CTS 用量为2. 05% (o. w. f)时,PANI/ CTS/ 羊毛复合导电织物的电导率达到11. 32 S/ cm;羊毛角蛋白分子表面非均匀电场分布导致苯胺非均匀吸附,而CTS 氨基质子化有助于弱电场区域的苯胺吸附,使得苯胺整体吸附量更多,均匀度更好,聚合形成更加均匀、致密的PANI 层,提高了复合织物的导电性能。     

壳聚糖基复合膜的制备及其对蛋白质的吸附

此次试验利用戊二醛将壳聚糖(CTS)与β-环糊精(β-CD)进行交联,采用流延法制备(CTS/β-CD)复合膜,并对黄浆水中蛋白质进行吸附。利用傅里叶变换红外光谱仪(FT-IR)、扫描电镜(SEM)对CTS/β-CD复合膜进行表征,结果证明合成了CTS/β-CD复合膜;对CTS/β-CD复合膜进行溶胀度测定,结果证明复合膜的溶胀度低于CTS膜本身,在废水处理中更加稳定,透射率的测定证明复合膜表面有β-CD微粒。进一步以蛋白质吸附量为考察指标,优化CTS/β-CD复合膜制备和吸附条件,结果表明,制备条件为CTS与β-CD质量比1︰1,反应温度45℃,氢氧化钠(NaOH)质量分数4%;吸附条件为pH 5、稀释倍数1倍。此时黄浆水中蛋白质吸附量最佳,为4.406 mg/g。     

层析填料中顽固色素去除的新方法研究

对纯化工艺中因铁离子污染形成黄褐色的阴离子填料进行了研究.该色素在碱性条件下产生并加重,利用常规方法高盐、表面活性剂均无法清除.作者使用磷酸、醋酸、柠檬酸、盐酸进行测试,发现浓磷酸去除填料色素的能力高于柠檬酸,而浓醋酸和浓盐酸不能明显去除填料色素.基于上述结论,进一步研究磷酸在不同浓度和不同处理时间下对填料中色素的影响...     

壳聚糖对银离子的吸附性能研究

壳聚糖（Chitosan,CTS）是自然界中储量仅次于纤维素的最丰富的天然高分子材料,其大分子链上含有较多的羟基、氨基等活性基团,已广泛用作各种载体材料.本文研究了壳聚糖对Ag＋的吸附性能,考察了不同条件下壳聚糖对Ag＋的吸附关系.pH值的提高和作用时间的延长均使吸附率增加,而较低温度下更有利于Ag＋的吸附,初始Ag＋浓度的高低对吸附量影响较大.     

Photocatalytic oxidation of arsenite in TiO2 suspension: kinetics and mechanisms

Arsenite [As(III)] and arsenate [As(V)] are highly toxic aquatic contaminants. Since arsenite is more mobile in natural waters and less efficiently removed in adsorption/coagulation processes than arsenate, the oxidation of arsenite to arsenate is desirable in water treatment. We performed the photocatalytic oxidation of arsenite in aqueous TiO2 suspension and investigated the effects of pH, dissolved oxygen, humic acid (HA), and ferric ions on the kinetics and mechanisms of arsenite oxidation. Arsenite oxidation in UV-illuminated TiO2 suspension was highly efficient in the presence of dissolved oxygen. Homogeneous photooxidation of arsenite in the absence of TiO2 was negligibly slow. Since the addition of excess tert-butyl alcohol (OH radical scavenger) did not reduce the rate of arsenite oxidation, the OH radicals should not be responsible for As(III) oxidation. The addition of HA increased both arsenite oxidation and H2O2 production at pH 3 under illumination, which could be ascribed to the enhanced superoxide generation through sensitization. We propose that the superoxide is the main oxidant of arsenite in the TiO2/UV process. The addition of ferric ions also significantly enhanced the arsenite photooxidation. In this case, the addition of tert-butyl alcohol reduced the arsenite oxidation rate, which implied thatthe OH radical-mediated oxidation path was operative in the presence of ferric ions. Since both Fe3+ and HA that were often found with the arsenic in groundwater were beneficial to the photocatalytic oxidation of arsenite, the TiO2/UV process could be a viable pretreatment method. This can be as simple as exposing the arsenic-polluted water in a TiO2-coated trough to sunlight.     

壳聚糖吸附亚硒酸的动力学研究

研究了壳聚糖对亚硒酸的吸附性能,测定了吸附等温线和吸附动力学曲线。实验结果表明壳聚糖对亚硒酸有较强的吸附能力,吸附容量受pH值影响较大,其吸附行为符合Langmuir单分子层吸附模型。紫外和红外光谱分析结果也表明壳聚糖与亚硒酸之间发生的是简单的物理吸附作用,而非配合反应。     

棉织物的壳聚糖金属配合物/H2O2室温漂白

通过壳聚糖在极稀的溶液中与金属离子Cu2+、Zn2+进行配位,形成2种壳聚糖金属配合物,研究这2种配合物催化H2O2氧化分解的动力学和对棉织物的室温漂白效果。结果表明：壳聚糖金属配合物在室温下能够较好地催化H2O2分解,分解率符合表观一级反应动力学;pH值、配合物初始浓度是影响壳聚糖金属配合物催化性能的重要因素。CTS′- Zn(II)配合物初始质量浓度为3g/L,pH值为11时催化效果最好;CTS′- Cu (II)配合物初始质量浓度为3g/L,pH值为8时催化效果最好。对棉织物的室温漂白效果与传统工艺相近,且强力保留率能达到90%以上。     

Inhibitory effect of high concentrations of ferric ions on the activity of Acidithiobacillus ferrooxidans

The influence of high concentrations of ferric ions on the biochemical activity of Acidithiobacillus ferrooxidans was studied using intact cells. The specific oxidation rate of ferrous ions decreased with increasing ferric ion concentration. Lineweaver-Burk plots revealed typical competitive inhibition kinetics, because the slopes varied with the ferric ion concentration. A linear relationship between the slope and the square of the ferric ion concentration revealed that the iron-oxidizing enzyme system of A. ferrooxidans was competitively inhibited by about two molecules of ferric ion. The kinetic equation based on this inhibition model agreed with the experimental observation at a high ferric ion concentration where the bacterium is usually exposed in bioleaching and biooxidation plants.     

Influence of dietary phenolic acids on redox status of iron: Ferrous iron autoxidation and ferric iron reduction

We investigated the effect of dietary phenolic acids on the oxidation of Fe²⁺ caused by molecular oxygen. All phenolic acids bearing 3,4-dihydroxy (catechol) or 3,4,5-trihydroxy (galloyl) moiety formed chelates with ferric iron and significantly increased the rate of Fe²⁺ autoxidation. The carboxylate group and catechol substitution instead of galloyl moiety facilitated the ferrous ion oxidation more effectively. Caffeic acid and protocatechuic acid, the strongest accelerators of Fe²⁺ autoxidation, were able to facilitate autoxidation at concentrations lower than 1% of the initial amount of Fe²⁺. Therefore chelates of these catecholic acids with iron displayed ferroxidase-like activity. Conversely, when we started from ferric ions, catechols partially formed ferrous ions in the presence of ferrozine. Thus, catecholic acids formed stable chelates with iron, in which ferric ion is the dominant species, but the redox cycling of iron between Fe²⁺ and Fe³⁺ in chelates probably plays a crucial role in the catalysis of ferrous iron autoxidation. Interestingly, 3-hydroxybenzoic acid, 4-hydroxybenzoic acid and vanillic (4-hydroxy-3-methoxybenzoic) acid protected ferrous ions from autoxidation as effectively as ascorbic acid and cysteine. These monophenolic acids, differently from ascorbic acid and cysteine, were not able to reduce ferric ions. Syringic (3,5-dimethoxy-4-hydroxybenzoic) acid did not alter the redox state of iron, only in a large excess over metal, syringic acid slightly inhibited ferrous ions autoxidation and partially reduced ferric ions. Therefore, the effects of syringic acid at high concentration were similar but much lower to those of ascorbic acid and cysteine. The biological importance of ferroxidase-like activity of polyphenols, especially the influence on iron absorption, is also discussed.     

Using a surface complexation model to predict the nature and stability of nanoparticles

Nanoparticles are discrete nanometer-scale assemblies of atoms and have dimensions between those characteristic of ions and those of macroscopic materials. These minerals commonly possess extremely large specific surface areas and surface adsorption capacities for foreign ions. Due to the large specific surface area and large fraction of surface atoms, the natures of nanoparticles are expected to be modified by the adsorption (surface complexation) process. In this paper,we discuss theoretically the stability of nanoparticles that make the surface complex with foreign ions. The principal theoretical assumption is that the surface complexation occurs at the bulk of the nanoparticles, as in a solid solution. The surface complexation affects two aspects of the intrinsic stability of the nanoparticles simultaneously: one is the composition of the nanoparticles; the other is the free energy of formation of nanoparticles. The solubility of hydrous ferric oxide (HFO) was estimated by using surface complexation modeling coupled with published data of the free energy of formation of the relevant components. The solubility modeling of surface-charged (H+ or OH- sorbed) HFO mechanistically and quantitatively explained the observed nonintegral behavior of the solubility of HFO. Moreover, solubility modeling of anion (SO4(2-), PO4(3-), and As(V)) sorption by HFO showed that the sorption process strongly influences the stability of the nanoparticles. This result implies that geochemical modeling leads to the erroneous prediction of a natural system if the effect of the sorption process is not taken into account.