氨基双四唑型金属螯合磁性纳米粒子的制备及其对蛋白质的吸附性能

通过4步化学反应对磁性Fe3O4@Si02纳米粒子进行化学修饰,设计和制备了一种N,N’-二(5-四唑亚甲基)胺修饰的金属螯合磁性纳米粒子.用X射线光电子能谱(XPS)、Zeta电位对该新型吸附剂进行了表征.用静态吸附法研究了螯合Cu(Ⅱ)吸附剂对溶菌酶、细胞色素C和α-糜蛋白酶的吸附性能以及溶液pH值、盐浓度、蛋白初始浓度对吸附量的影响.结果表明,吸附剂对蛋白质的吸附主要通过金属配位机理进行,且符合Langmuir吸附模型,对溶菌酶、细胞色素C和α-糜蛋白酶的最大吸附量分别20.0、13.5和17.9 mg/g.此外,将螯合Cu(Ⅱ)吸附剂用于混合蛋白质样品的吸附,发现此吸附剂对混合蛋白质样品中的溶菌酶具有选择性吸附作用,说明此金属螯合吸附剂在蛋白质选择性分离富集中具有一定应用价值.     

功能化介孔硅材料的合成及其对富含裸露组氨酸蛋白质的选择性吸附

通过自由基聚合反应合成了具有高比表面积的介孔硅(PPOSS),并对其表面进行修饰和铜离子(Cu~(2+))的固定,最终得到功能化介孔硅材料(PPOSS-IDA-Cu~(2+)),然后利用PPOSS-IDA-Cu~(2+)中的Cu~(2+)与蛋白质裸露组氨酸的螯合作用,选择性吸附富含裸露组氨酸的蛋白质。对牛血红蛋白、牛血清白蛋白、肌红蛋白和溶菌酶的吸附结果表明,所合成的PPOSS-IDA-Cu~(2+)材料对富含组氨酸的牛血红蛋白有较好的吸附选择性和较大的吸附容量(3 150mg/g),并且有望与其他材料联合使用,以检测到更多相对丰度较低的蛋白质,丰富人类蛋白质组学信息,为疾病的临床诊断及病理研究提供帮助。     

尿毒症中分子毒物吸附剂的研究——Ⅱ. 交联剂链长对壳聚糖树脂吸附性能的影响

用甲醛、乙二醛和戊二醛作为交联剂,以反向悬浮的方法制备了3种不同的交联壳聚糖树脂吸附剂,并对其中的后两种用NaBH₄进行了还原处理.经红外光谱表征和扫描电子显微镜观察,氢化还原处理有效地提高了吸附剂的化学稳定性;而交联剂的不同则对吸附剂的表面形态有着明显的影响.通过对尿毒症中分子毒物的模拟物和牛血清白蛋白的吸附研究发现,3种壳聚糖树脂吸附剂都在符合临床血液灌流要求的时间里达到了吸附平衡,在对牛血清白蛋白几乎不发生吸附作用的同时,其对模拟的中分子毒物则都产生了一定的吸附作用,但吸附量有所不同;随着交联剂脂肪链的增长,吸附剂对模拟的中分子毒物的吸附能力逐渐增强;以戊二醛为交联剂时,吸附剂的吸附效果最好.     

树脂填充EVAL中空纤维膜吸附剂的吸附及脱附性能研究

以亲水性乙烯-乙烯醇共聚物(EVAL)为膜吸附剂基质材料,阳离子交换树脂D061为功能树脂,采用干-湿法纺丝技术,制备了树脂填充EVAL中空纤维膜吸附剂。实验采用连续循环膜过滤工艺,研究了这种吸附剂对目标蛋白(牛血清白蛋白-BSA)的吸附和脱附性能。考察了树脂填充量、缓冲溶液pH值等对蛋白质吸附和脱附性能的影响。实验结果表明,树脂填充EVAL中空纤维膜吸附剂对目标蛋白BSA具有较高的吸附容量和脱附率,随着树脂填充量的增加,膜吸附剂对BSA吸附容量增加,并且最大吸附容量在牛血清蛋白等电点(4.8～5.2)附近出现。当树脂填充量65%,缓冲溶液pH4.5时树脂填充EVAL中空纤维膜吸附剂对BSA的吸附容量可达到71.47mgBSA/g膜吸附剂。     

Ag-Y/MIL-101吸附剂的制备及其吸附脱硫性能

通过银、钇双金属改性制备了Ag-Y/MIL-101吸附剂,并对Ag-Y/MIL-101进行了X射线衍射(XRD)、电镜(SEMEDS)、比表面积(BET)和热重(TG-DTG)表征。考察了Ag-Y/M IL-101金属负载顺序、金属负载浓度、金属溶液用量、负载时间对脱硫性能的影响,优化了吸附脱硫条件。结果表明,金属改性得到的Ag-Y/MIL-101保持了MIL-101的晶格结构。与M IL-101相比,Ag-Y/MIL-101的比表面积和孔容均有所下降。适宜Ag-Y/MIL-101的制备条件为:先负载银后负载钇,银离子和钇离子的负载浓度均为30 mmol/L,金属溶液用量均为1 mL,负载时间为8 h。适宜Ag-Y/MIL-101的吸附脱硫条件为:吸附剂用量0.05 g,模拟油为10 mL,吸附温度为60℃,吸附时间为8 h。在此条件下,Ag-Y/MIL-101对噻吩的吸附量达到21.7 mg/g。Ag能显著提高MIL-101的吸附硫容,Y能显著提高MIL-101的吸附选择性,因此,Ag-Y/MIL-101吸附剂中Ag和Y的协同作用使其拥有比MIL-101更高的硫容和噻吩脱硫选择性。     

普施安蓝掺杂二氧化硅纳米棒制备及其对蛋白识别性能研究

能够有效富集、分离蛋白质的人工合成材料在蛋白质组学研究中具有重要应用价值。本文利用氨丙基三乙氧基硅烷的氨基与普施安蓝分子中三嗪环上氯原子之间的取代反应生成普施安蓝修饰的烷氧基硅烷,在四乙氧基硅烷存在下,通过自组装溶胶-凝胶法制备了普施安蓝掺杂的二氧化硅纳米棒。扫描电镜表征显示纳米棒的长度在2~16 μm之间,直径在200~500 nm之间。红外光谱、热重-差示扫描量热法表征结果表明: 普施安蓝被成功掺入二氧化硅纳米棒。所制备纳米棒对牛血清白蛋白的吸附容量达到57.6 mg/g, 30 min内达到饱和容量的80%。通过对不同蛋白质的吸附研究表明: 其对胰蛋白酶和溶菌酶表现了较好的吸附,吸附量分别为87.5 mg/g和59.8 mg/g;而其几乎不吸附牛血红蛋白和胃蛋白酶,尤其是对牛血红蛋白的吸附量只有3 mg/g。以上研究结果表明: 所制备纳米棒材料不仅对蛋白质有较高的吸附容量,而且也表现出良好的选择性,该材料有望进一步应用于蛋白质组学中对相关蛋白质的富集与分离。     

π络合脱硫吸附剂Cu(Ⅰ)-Y的生物再生

吸附与生物技术的耦合是实现燃料油品清洁生产的新发展方向, 提出了一种吸附剂生物再生循环使用的新耦合方法, 首先用吸附剂吸附脱除油品中的含硫化合物, 然后用微生物脱附吸附剂表面吸附的硫化物, 实现吸附剂再生. 利用Y型分子筛通过离子交换再用He保护自动还原的方法制备了(络合吸附剂吸附Cu(Ⅰ)-Y, 以DBT为模型化合物考察了吸附剂的吸附性能. 以选择性脱硫菌德氏假单胞菌(Pseudomonas delafieldii)R-8为生物催化剂, 考察了细胞浓度、油相体积、水相/吸附剂比对吸附剂脱附率的影响. 加入油相可以大大提高DBT脱附量和生成2-HBP的量. 增加水相中脱硫菌R-8的浓度、增大水相/吸附剂比, 可以实现DBT脱附, 促进DBT转化为2-HBP. 在水相脱硫菌株R-8浓度为75 g·L-1、水相/吸附剂比为300 mL/g、油相/水相比1/3(V/V)的条件下, 脱附的DBT在6 h内转化率达到89%, 24 h内转化率为100%. 生成2-HBP的量主要由吸附剂吸附硫化物的量、水相中微生物细胞的浓度、油相/水相体积比、水相/吸附剂比决定. 吸附剂经过正辛烷洗涤、100℃下干燥24 h、He保护450℃还原活化3 h, 再生吸附剂的吸附能力为新鲜吸附剂的95%.     

表面活性剂和染料探针共振光散射法测定蛋白质

在pH为2.1的Britton-Robinson缓冲溶液中,蛋白质与十二烷基磺酸钠和吖啶红作用形成聚集体,导致体系产生较大的共振散射光(RLS)强度,并且RLS的增强程度与蛋白质的浓度呈线性关系,据此建立了测定蛋白质含量的方法.人血清白蛋白(HSA)和牛血清白蛋白(BSA)分别在0.03～3.0μg/mL和0.2～7.0μg/mL的浓度范围内与增强的共振光散射强度有良好的线性关系,相应的检测限分别为0.0119μg/mL和0.026μg/mL.对体系的反应机理进行了讨论.将方法用于人血清中蛋白质含量的测定,并将分析结果与考马斯亮蓝法进行了对照.t-检验证明,两种方法无显著性差异.     

树脂填充聚醚砜纤维吸附剂对牛血清蛋白吸附性能的研究

重点研究树脂填充聚醚砜(PES)纤维吸附剂与模型蛋白质牛血清蛋白(BSA)之间的吸附与脱附行为.结果表明,蛋白质BSA在树脂填充PES纤维吸附剂中的平衡吸附过程较好地符合朗格缪尔吸附模型,树脂Lewatit CNP80ws填充PES吸附剂的最大吸附容量约为139mg BSA/g吸附剂.表面具有开孔结构的树脂填充PES纤维吸附剂的吸附速率较快,在不同结构纤维吸附剂中BSA的扩散系数在1·82×10-14~8·7×10-14m2/s范围内变化.另外,考察了BSA溶液的pH与洗脱剂等因素对吸附剂吸附与脱附性能的影响,研究结果对蛋白质的实际分离纯化具有重要的参考价值.     

π络合脱硫吸附剂Cu(I)-Y的生物再生

吸附与生物技术的耦合是实现燃料油品清洁生产的新发展方向,提出了一种吸附剂生物再生循环使用的新耦合方法,首先用吸附剂吸附脱除油品中的含硫化合物,然后用微生物脱附吸附剂表面吸附的硫化物,实现吸附剂再生.利用Y型分子筛通过离子交换再用He保护自动还原的方法制备了π络合吸附剂吸附Cu(I)-Y,以DBT为模型化合物考察了吸附剂的吸附性能.以选择性脱硫菌德氏假单胞菌(Pseudomonasdelafieldii)R-8为生物催化剂,考察了细胞浓度、油相体积、水相/吸附剂比对吸附剂脱附率的影响.加入油相可以大大提高DBT脱附量和生成2-HBP的量.增加水相中脱硫菌R-8的浓度、增大水相/吸附剂比,可以实现DBT脱附,促进DBT转化为2-HBP.在水相脱硫菌株R-8浓度为75g·L?1、水相/吸附剂比为300mL/g、油相/水相比1/3(V/V)的条件下,脱附的DBT在6h内转化率达到89%,24h内转化率为100%.生成2-HBP的量主要由吸附剂吸附硫化物的量、水相中微生物细胞的浓度、油相/水相体积比、水相/吸附剂比决定.吸附剂经过正辛烷洗涤、100℃下干燥24h、He保护450℃还原活化3h,再生吸附剂的吸附能力为新鲜吸附剂的95%.     

A NOVEL METAL CHELATE AFFINITY ADSORBENT FOR PROTEIN UPTAKE

In this article,a spherical chitosan gel crosslinked by epichlorohydrin was prepared.It was then loaded with copper ions to produce a metal chelate affinity adsorbent for protein.The uptake of bovine serum albumin(BSA)by the affinity adsorbent was investigated.and the adsorption capacity for BSA as high as 40mg/g-wet beads was observed.The adsorption equilibrium data was well correlated by the Langmuir equation.The adsorption was considerably affected by pH.In additio.The amount of BSA adsorbed onto the beads decreased with the increasing of aqueous phase ionic strength,so adsorbed BAS can be desorbed by adjusting pH orionic strength of the solution.     

A NOVEL METAL CHELATE AFFINITY ADSORBENT FOR PROTEIN UPTAKE

1. INTRODUCTION Chitosan is a hydrolyzed derivative of chitin and belongs to a family of linear unbranched polysaccharides which contain large amounts of 1,4-linked-2-amino-2-deoxy-β-D-glucan residues. The presence of free amine groups in chitosan enhances the solubility and reactivity of this polymer. Interest in modifying chitosan by using glutaraldehyde has recently increased. The derivatized polymers have been employed for many applications [1~2], including protein immobilization…     

One-pot preparation of silica-supported hybrid immobilized metal affinity adsorbent with macroporous surface based on surface imprinting coating technique combined with polysaccharide incorporated sol--gel process

A simple and reliable one-pot approach using surface imprinting coating technique combined with polysaccharide incorporated sol-gel process was established to synthesize a new organic-inorganic hybrid matrix possessing macroporous surface and functional ligand. Using mesoporous silica gel being a support, immobilized metal affinity adsorbent with a macroporous shell/mesoporous core structure was obtained after metal ion loading. In the prepared matrix, covalently bonded coating and morphology manipulation on silica gel was achieved by using one-pot sol-gel process starting from an inorganic precursor, -glycidoxypropyltrimethoxysiloxane (GPTMS), and a functional biopolymer, chitosan (CS) at the atmosphere of imprinting polyethylene glycol (PEG). Self-hydrolysis of GPTMS, self-condensation, and co-condensation of silanol groups (Si-OH) from siloxane and silica gel surface, and in situ covalent cross-linking of CS created an orderly coating on silica gel surface. PEG extraction using hot ammonium hydroxide solution gave a chemically and mechanically stabilized pore structure and deactivated residual epoxy groups. The prepared matrix was characterized by using X-ray energy dispersion spectroscopy (EDX), scanning electron microscopy (SEM) and mercury intrusion porosimetry. The matrix possessed a high capacity for copper ion loading. Protein adsorption performance of the new immobilized metal affinity adsorbent was evaluated by batch adsorption and column chromatographic experiment using bovine serum albumin (BSA) as a simple model protein. Under the optimized coating conditions, the obtained macroporous surface resulted in a fast kinetics and high capability for protein adsorption, while the matrix non-charged with metal ions offered a low non-specific adsorption.     

水杨酸型螯合吸附材料对重金属离子的吸附性能

将5-氨基水杨酸接枝到PGMA/SiO2微粒的聚甲基丙烯酸缩水甘油酯(PGMA)大分子链上,成功制备了一种新型螯合吸附材料ASA-PGMA/SiO2。采用静态法研究了ASA-PGMA/SiO2对重金属离子Cu2+、Cd2+、Zn2+、Pb2+的吸附性能,结果表明其对Cu2+、Cd2+、Zn2+、Pb2+具有很强的螯合吸附能力,吸附容量分别可以达到0.42、0.40、0.35、0.31mmol/g。体系的pH对吸附容量影响较大,吸附行为服从Langmuir和Freundlich吸附模型。使用0.1mol/L的盐酸溶液就可实现重金属离子的解吸。通过反复吸附-解吸实验证明ASA-PGMA/SiO2具有良好的重复使用性能。     

Enhancement of Cd2+ removal on CuMgAl-layered double hydroxide/montmorillonite nanocomposite: Kinetic,isotherm, and thermodynamic studies

In recent decades, great progress has been made in the application of adsorption processes to mitigate water pollution by hazardous metals. However, developing a highly efficient adsorbent is essential if the adsorption process is to be successfully applied in practical applications. In this study, a CuMgAl-layered double hydroxides/montmorillonite nanocomposite (CuMgAl-LDH/MMt) was prepared, characterized, and then used as a novel adsorbent for adsorption of Cd²⁺ ions from wastewater. The effects of initial pH, adsorbent dosage, agitation speed, particle size, contact time, initial Cd²⁺ concentration, and temperature on the pollutant removal efficiency were analyzed. An isotherm model reading revealed that the results of the experimental work were a good fit with the Freundlich model. The maximum adsorption capacity was reached at 174.87 mg/g under optimal conditions (pH 5, dosage of 0.02 g/l, agitation speed of 150 rpm, and particle size of 87 μm) at 50 ppm after 120 min of adsorption time. Kinetic studies showed that pseudo-second-order models were best fitted to the adsorption data, indicating heterogeneous adsorption of Cd²⁺ ions onto multilayer CuMgAl-LDH/MMt sites, and that the adsorption process is primarily chemical adsorption. Thermodynamic parameters (ΔS^o, ΔH^o, and ΔG^o) demonstrated that Cd²⁺ adsorption onto adsorbent was exothermic and spontaneous. Moreover, the synthesized adsorbent can be recovered after five consecutive cycles with a minimal reduction in the adsorption ability of 29.56 %. The study showed that specific heavy metals can be removed from aqueous solution by a newly prepared adsorbent due to its excellent morphology, high stability under a wide range of conditions, recyclability, and high adsorption capacity.     

ADSORPTION OF PHENOL AND Pb^2＋ FROM AQUEOUS SOLUTIONS BY A NEW DI-FUNCTION ADSORBENT WITH SULFHYDRYL GROUPS

A new di-function adsorbent （JN-3） was prepared by sulfhydryl modified. Comparing with Amberlite XAD-4 and NDA-150, the equilibrium adsorption for phenol on the JN-3 from aqueous solutions was tested, perfect adsorption capacity was shown. Pb^2＋ can be also removed by JN-3 because of the chelate interaction between sulfhydryl groups and metal ions. This adsorbent could be used in removal of combine pollutants such as phenolic compounds and heavy metal ions from waste streams.     

载铁(Ⅲ)-配位体交换棉纤维素吸附剂对饮用水中砷(Ⅴ)和氟联合去除的研究

使用新型载铁(Ⅲ)-配位体交换棉纤维素吸附剂,通过静态和动态吸附实验,研究了饮用水中砷酸钠[砷(Ⅴ)]和氟化钠(氟)联合去除的效果和浓度因素的影响以及吸附剂经过反复吸附-洗脱再生-再吸附后性能的稳定性.结果表明,该吸附剂能够高效、高选择性地联合去除高砷(Ⅴ)和高氟.吸附柱的饱和吸附容量可高达15mg/g干重,反复使用中饱和体积的相对标准偏差小于0.5%,柱处理出水的各项有关指标均符合我国生活饮用水卫生标准,特别是砷(Ⅴ)的质量浓度低于0.010mg/L,符合世界健康组织(WHO)推荐的饮用水严格砷标准.说明该吸附剂在砷氟共存的地区具有很好的应用前景.     

ADSORPTION BEHAVIORS OF Pt（IV） AND Pd（II） ON POLYMERIC ESTER THIOUREA RESIN

Polymeric ester thiourea resin （PDTU-I） is a new kind of chelating resin with functional atoms S, N and O, so it is an excellent adsorbent for noble metal ions. In batch testes, the adsorption capacities of PDTU-I for Pt（IV） and Pd（II） increase with the increase of contact time, temperature and initial concentration of metal ions. The adsorption data fit Boyd＇s diffusion equation of liquid film, Langmuir adsorption isotherm and Freundlich adsorption isotherm. The maximum adsorption capacities calculated by Langmuir equation are 2.54mmol/g for Pt（IV） and 4.88mmol/g for Pd（II）. According to FTIR and XPS results, functional groups of PDTU-I coordinate with noble metal ions in the adsorption process.     

硫脲基纳米螯合纤维对水溶液中Cd(Ⅱ)的吸附和密度泛函理论计算

以聚丙烯腈为原料, 利用静电纺丝技术和化学接枝制备得到硫脲基纳米螯合纤维, 并用于水溶液中 Cd(Ⅱ)的去除. 结合样品的表征和密度泛函(DFT)理论计算结果, 揭示了所制备纳米纤维材料对Cd(Ⅱ)的吸附机理. 借助静态吸附和动态吸附实验, 考察了硫脲基纳米螯合纤维对Cd(Ⅱ)的吸附性能. 结果表明, 纳米纤维吸附材料对Cd(Ⅱ)的最大吸附容量可达349.46 mg/g, 吸附过程在90 min以内即可达到基本平衡. 整个吸附过程符合准二级动力学模型和Langmuir等温吸附模型. 硫脲基纳米螯合纤维吸附Cd(Ⅱ)的吸附机理为表面配位络合, 增加纳米纤维表面硫脲基团的含量是提高吸附容量的重要途径. 该吸附材料经6次循环使用后, 最大动态吸附容量并未发生明显改变.     

Removal of cadmium(II) and lead(II) ions from model aqueous solutions using sol–gel-derived inorganic oxide adsorbent

A study was conducted concerning the preparation and application of a novel synthetic oxide adsorbent of MgO-SiO₂ type. The material was prepared via a sol–gel route, utilizing magnesium ethoxide and tetraethoxysilane as precursors of magnesium oxide and silica respectively, and ammonia as a catalyst. The powder was comprehensively analyzed with regard to chemical composition (EDS method), crystalline structure, morphology, characteristic functional groups, electrokinetic stability and porous structure parameters (BET and BJH models). The synthesized oxide adsorbent is amorphous, with irregularly shaped particles, a relatively large surface area of 612 m²/g, and negative surface charge over almost the whole pH range. Comprehensive adsorption studies were performed to investigate the adsorption of Cd(II) and Pb(II) ions on the MgO–SiO₂ oxide adsorbent, including evaluation of adsorption kinetics and isotherms, the effect of pH, contact time and mass of adsorbent. It was shown that irrespective of the conditions of the adsorption process, the synthesized MgO–SiO₂ adsorbent exhibits slightly better affinity to lead(II) than to cadmium(II) ions (sorption capacity of 102.02 mg(Pb²⁺)/g and 94.05 mg(Cd²⁺)/g). The optimal time for removal of the analyzed metal ions was 60 min, although adsorption reached equilibrium within 10 min for Pb(II) and within 15 min for Cd(II) ions, which was found to fit well with a type 1 pseudo-second-order kinetic model. Additionally, adsorption efficiency was affected by the pH of the reaction system—better results were obtained for pH ≥7 irrespective of the type of metal ion.