碳羟基磷灰石对电镀废水中Zn~(2+)的吸附性能

在静态条件下,对碳羟基磷灰石吸附Zn2+的电镀废水进行了研究,探讨了碳羟基磷灰石用量、废水pH值、吸附时间、吸附温度对去除Zn2+的影响.结果表明,在废水pH值6.0～7.0,Zn2+浓度0～100mg/L,吸附时间为70 min,吸附温度为35℃条件下,按Zn2+与碳羟基磷灰石质量比为1:35投加碳羟基磷灰石进行处理,Zn2+去除率可达98%以上.合Zn2+的电镀废水经碳羟基磷灰石吸附后,废水中Zn2+的含量低于国家一级排放标准.     

水热法调控羟基磷灰石/壳聚糖的制备及其对蛋白质吸附性能的研究

在碱性环境下,以壳聚糖乙酸溶液与羟基磷灰石前驱体为基质,通过水热法成功制备出羟基磷灰石/壳聚糖(HAp/CS)复合材料,采用X射线衍射、傅里叶变换红外光谱和场发射扫描电镜等检测方法对复合材料进行表征。考察了壳聚糖掺杂量、吸附时间、PO_4~(3-)浓度、pH对牛血清蛋白(BSA)和溶菌酶(LYS)吸附性能的影响。结果表明:在吸附时间为24h时吸附基本保持平衡,pH=4时对BSA吸附效果最好,pH=11时对LYS吸附效果最好,溶液中PO_4~(3-)对吸附有抑制作用,复合材料对LYS的吸附效果明显优于BSA,吸附过程符合Langmuir模型。     

介孔纳米羟基磷灰石对刚果红染料吸附性能的研究

以氯化钙、磷酸氢二铵、十六烷基三甲基溴化铵为原料，采用水热合成工艺制备了介孔纳米羟基磷灰石，并用X射线衍射仪、扫描电子显微镜和比表面积分析仪对其进行物相、形貌和结构进行表征，然后着重研究了介孔纳米羟基磷灰石在各种不同条件下对刚果红染料的吸附性能。结果表明：介孔纳米羟基磷灰石的微观形貌为针棒状，比表面积为29.7376m²/g,平均孔径为41.558nm,孔体积为0.325196cm³/g。介孔纳米羟基磷灰石材料对刚果红染料具有较好的吸附性能，当溶液pH为7时，介孔纳米羟基磷灰石对刚果红吸附效果最好，最大吸附量可达183.77mg/g。通过模型拟合可知介孔纳米羟基磷灰石对刚果红的吸附过程符合准二级动力学模型和朗格缪尔等温吸附模型，属于自发的吸热过程。因此，介孔纳米羟基磷灰石可以作为绿色生物吸附剂用于染料的吸附。     

纳米羟基磷灰石粉体的生物活性的研究

采用溶胶-凝胶法制备羟基磷灰石陶瓷材料.通过控制工艺参数:pH>9,Ca/P=1.67,烧结温度为1100℃及烧结时间2h,合成出纯度较高纳米粒径的羟基磷灰石粉体.通过羟基磷灰石对不同氨基酸的吸附强度,选取显著吸附的氨基酸进行紫外分光光度法、X射线衍射(XRD)物相分析和X射线衍射谱(XDS)分析,研究羟基磷灰石粉体的结构和吸附氨基酸的生物活性.结果表明:羟基磷灰石能吸附氨基酸,吸附位点是PO43-基,而不是Ca2+.提出羟基磷灰石吸附具有不同电位的氨基酸的作用机理.     

硅烷偶联剂KH-570表面修饰羟基磷灰石的结构与吸附性能研究

采用硅烷偶联剂KH-570对羟基磷灰石粉体进行表面修饰,使羟基磷灰石在聚合物介质中有较好的相容性和分散稳定性。采用红外光谱、热重、差热、激光粒度、Zeta电位和X射线衍射等方法对表面修饰前后的羟基磷灰石进行表征分析。结果表明,KH-570硅烷偶联剂结合在羟基磷灰石表面,并未对其晶体产生明显影响;羟基磷灰石经修饰后在水溶液中的Zeta电位绝对值增加,分散稳定性提高,粒子团聚程度降低,纳米级颗粒尺寸从272.8nm减小到166nm,Cd2+吸附性能随增重率的增加而降低。     

非均相悬浮法制备多孔羟基磷灰石微球

为了获得具有吸附和生物学功能的多孔羟基磷灰石(HA)微球,以自制的纳米羟基磷灰石(HA)粉体为原料,用非均相悬浮法制备了HA/明胶微球,将微球在1 250℃下焙烧,成功制备了直径100~500μm的多孔HA微球.采用光学显微镜、SEM分析、XRD分析和BET氮吸附法研究了微球形貌、尺寸、物相组成、比表面积和孔径,测定了微球对水中F-离子的吸附性能.结果表明:微球具有良好球形形貌和相互贯通的纳米微孔;尺寸比较均匀,分散性良好;微球的主要结晶相为羟基磷灰石;BET表面积为1.867 0~2.089 5 m~2/g,孔径6.53~6.85 nm;对氟离子的平衡吸附容量为1.909~1.940 mg/g.通过控制m(HA)/m(明胶)比例、油温、搅拌速度和搅拌时间,可以在一定范围内控制微球直径和比表面积.     

羟基磷灰石表面吸附性能的研究综述

羟基磷灰石(HA)吸附能力受酸碱度、其它离子浓度等外界因素的影响,对HA表面改性处理能在一定程度上改变HA表面电性结构,从而改善吸附性能.动力学上多因素作用影响HA吸附速度或改变具体的吸附行为.通过总结HA对无机物、金属及有机物的作用条件、反应过程及吸附机理发现:人们还没有找到一个普遍的理论模型来解释HA与其它材料发生吸附作用的过程,目前对HA表面吸附性能的研究还停留在具体零碎材料的相互作用上.在HA表面嫁接有用的作用基团或物质,通过改变HA表面部分结构以改善吸附性能成为目前和今后一段时间内HA吸附性能研究的重点之一.     

碳羟基磷灰石/钾长石复合材料的制备与表征

以钾长石为原料,用液相合成法制备碳羟基磷灰石/钾长石复合材料(CK)。以200mg/L Ni ~(2+)的吸附率为指标,通过单因素实验和响应面分析法得出其最优制备条件:CO_3~(2-)与PO_4~(3-)的摩尔比0.23,钾长石与羟基磷灰石的质量比0.4,搅拌时间2h,搅拌温度43.1℃,陈化时间24h。此时,CK对Ni ~(2+)的吸附率可达到92.9%。并利用扫描电镜(SEM)、X-射线衍射(XRD)、傅里叶红外光谱(FT-IR)以及BET比表面积等测试手段对CK进行表征,结果表明,碳羟基磷灰石均匀地负载在钾长石上,使其表面变得蓬松粗糙,与原料相比总孔体积、比表面积分别增大了近55、60倍。因此,CK有望成为一种新颖的去除重金属污染的环境矿物吸附材料。     

羟基磷灰石吸附性能与制备工艺研究新进展

羟基磷灰石(Hydroxyapatite,HA)独特的化学组成和晶体结构,使其具有良好而广泛的吸附性能,作为一种新型的环境友好材料和高效的吸附剂,其应用领域日益扩展.HA针对不同种类的目标物质其吸附机理不尽相同,因此对其制备方法也有不同要求.然而,相关的研究却鲜有报道.通过分析HA吸附重金属离子和蛋白质的差异,讨论了其吸附机理的异同和对制备方法的不同要求,并进一步分析不同吸附机理与制备方法之间的关系,展望了今后的研究方向.     

模拟体液法快速合成羟基磷灰石纳米针及其吸附性能研究

采用模拟体液法快速制备羟基磷灰石(HA)纳米针,并研究了HA对牛血清蛋白质(BSA)的吸附性能。采用XRD、TEM、SEAD和FT-IR等分析方法表征样品。结果表明:1min即可快速制备宽约5nm,长为50～80nm且分散良好的HA纳米针,形貌和尺寸与人体中的HA极为相似;反应时间影响合成产物的形貌及物相,短时间内延长反应时间有利于HA纳米针的生长,但反应时间过长会导致HA再次反应生成Ca3(PO4)2;同时,快速制备的HA纳米针具有很强的吸附性能。     

硅掺杂羟基磷灰石生物活性微粉对人血清白蛋白的吸附特性

对含硅羟基磷灰石(Si-HA)与人血清白蛋白(HSA)的吸附特性及动力学特征进行了研究,计算了表观活化能,用等温吸附曲线进行拟合。结果表明,该吸附属于Langmuir型。Si-HA和HA吸附HSA的表观活化能分别为21.28和35.57 kJ.mol-1,20℃下吸附反应的速率常数分别为1.48和1.34 min-1,饱和吸附量分别为25.34和21.34 mg.g-1,Si-HA具有比纯HA更好的吸附优势。通过XRD、FTIR及荧光光谱分析,探讨了HSA在Si-HA和HA表面的吸附作用机制,表明Si-HA与蛋白表面吸附反应是以化学吸附为主、包含物理吸附的混合吸附过程。从分子结构的角度揭示了Si-HA和HA吸附蛋白质性能的差异,为进一步探讨Si-HA和HA生物相容性提供了新途径。     

Adsorption of Cd(II) and Cu(II) from aqueous solution by carbonate hydroxylapatite derived from eggshell waste

Carbonate hydroxylapatite (CHAP) synthesized by using eggshell waste as raw material has been investigated as metal adsorption for Cd(II) and Cu(II) from aqueous solutions. The effect of various parameters on adsorption process such as contact time, solution pH, amount of CHAP and initial concentration of metal ions was studied at room temperature to optimize the conditions for maximum adsorption. The results showed that the removal efficiency of Cd(II) and Cu(II) by CHAP could reach 94 and 93.17%, respectively, when the initial Cd(II) concentration 80 mg/L and Cu(II) 60 mg/L and the liquid/solid ratio was 2.5 g/L. The equilibrium sorption data for single metal systems at room temperature could be described by the Langmuir and Freundlich isotherm models. The highest value of Langmuir maximum uptake, (b), was found for cadmium (111.1mg/g) and copper (142.86 mg/g). Similar Freundlich empirical constants, K, were obtained for cadmium (2.224) and copper (7.925). Ion exchange and surface adsorption might be involved in the adsorption process of cadmium and copper. Desorption experiments showed that CaCl2, NaCl, acetic acid and ultrasonic were not efficient enough to desorb substantial amount of metal ions from the CHAP. The results obtained show that CHAP has a high affinity to cadmium and copper.     

Synthesis of fluoride-releasing carbonate apatites for bone substitutes

Fluoride (F⁻)-substituted B-type carbonate hydroxyapatite (CHAP) powders were prepared for application as bone substitute materials having the ability to enhance bone formation and to suppress bone resorption due to the therapeutic effect of F⁻. F⁻ was adsorbed on CHAP in a sodium fluoride solution followed by heating at 700°C in carbon dioxide flow to substitute F⁻ for the hydroxyl ion in the CHAP structure. The F⁻ contents in the F-substituted CHAP powders were 16–22 times greater than that in normal adult human bones. The carbonate ion contents in the F-substituted CHAP powders corresponded to or were higher than that in normal adult human bones. F-substituted CHAP powder with CO₃²⁻ and F⁻ contents of 11.03 and 0.66 wt%, respectively, slowly released F⁻ in a physiological salt solution to a sufficiently high F⁻ level. The F⁻ concentration slowly increased and reached 67.20 ± 4.81 μg l⁻¹, which was 1.5–9.3 times higher than that in the body fluid of normal adult humans, near the therapeutic window of F⁻, and far lower than the estimated toxic level. Therefore, the F-substituted CHAP can promote bone formation. The present F-substituted CHAP has the advantage of slow F⁻ release over sodium fluoride and sodium monofluorophosphate which are highly soluble salts and cannot be sintered into a ceramic body.     

The adsorption characteristics of osteopontin on hydroxyapatite and gold

The adsorption of osteopontin on hydroxyapatite (HA) and reference gold (Au) surfaces was studied at different protein bulk concentrations over the temperature range 295-317 K, using quartz crystal microbalance with dissipation (QCM-D) and X-ray photoelectron spectroscopy (XPS). The QCM-D protein adsorption studies were complemented with polyclonal antibodies to examine the availability of protein sequences on the resulting protein layer. The QCM-D and XPS results show that the osteopontin surface mass uptake is larger on Au as compared to HA surfaces within the range of experimental conditions examined (protein bulk concentrations and temperature range), in accordance with the formation of a more compact protein film on Au. The specific antibody binding to the resulting adsorbed osteopontin layer as measured by QCM-D further confirms that the protein packing and conformational/orientational changes occurring during OPN adsorption on Au and HA are different, since fewer antibodies are observed to bind per OPN molecule on Au as compared to HA. The adsorption process on the respective surfaces was modeled using both the Langmuir and Hill adsorption isotherms, and from these isotherm curves, the Gibbs free energy, ?G, of the osteopontin adsorption was determined. The estimated ?G values indicate that the osteopontin molecules have a high affinity towards Au, while a lower affinity is observed between osteopontin and HA. By examining the changes in ?G as a function of temperature, we additionally find that the osteopontin adsorption on HA and Au is endothermic and driven by an increase in entropy.     

Porous spherical hydroxyapatite and fluorhydroxyapatite granules: processing and characterization

This study is aimed at the development of a method to fabricate porous spherical hydroxyapatite (HA)—fluorapatite (FA) granules. The method to produce porous granules is based on liquid immiscibility effect. A suspension of HA–FA powder mixtures in aqueous solution of gelatin and oil as a dispersion media were used. By stirring the mixtures of these immiscible liquids, granules of 50—200 mm diameter can easily be produced. The granules were characterized with respect to their microstructure, phase composition and specific area. In vitro testing of human plasma protein adsorption onto the granules of HA and fluorhydroxyapatite were performed. No kind of difference in the dynamic protein adsorption between pure HA and the HA up to 10 wt% FA materials has been revealed.     

Competitive adsorption of fibronectin and albumin on hydroxyapatite nanocrystals

Abstract

Competitive adsorption of two-component solutions containing fibronectin (Fn) and albumin (Ab) on hydroxyapatite (HAp) nanocrystals was analyzed in situ using the quartz crystal microbalance with dissipation (QCM-D) technique. Adsorption of the one-component protein (Fn or Ab) and the two-component proteins adjusted to different molar ratios of Fn to Ab at a fixed Fn concentration was investigated. The frequency shift (Δf; Hz) and the dissipation energy shift (ΔD) were measured with the QCM-D technique, and the viscoelastic changes of adlayers were evaluated by the saturated ΔD/Δf value and the Voigt-based viscoelastic model. For the adsorption of the one-component protein, the Fn adlayer showed a larger mass and higher viscoelasticity than the Ab adlayer, indicating the higher affinity of Fn on HAp. For the adsorption of the two-component proteins, the viscoelastic properties of the adlayers became elastic with increase in Ab concentration, whereas the adsorption mass was similar to that of Fn in the one-component solution regardless of the Ab concentration. The specific binding mass of the Ab antibody to the adlayers increased with increase in Ab concentration, whereas that of the Fn antibody decreased. Therefore, Fn preferentially adsorbs on HAp and Ab subsequently interacts with the adlayers, indicating that the interfacial viscoelasticity of the adlayers was dominated by the interaction between Fn and Ab.     

Competitive adsorption of fibronectin and albumin on hydroxyapatite nanocrystals

Competitive adsorption of two-component solutions containing fibronectin (Fn) and albumin (Ab) on hydroxyapatite (HAp) nanocrystals was analyzed in situ using the quartz crystal microbalance with dissipation (QCM-D) technique. Adsorption of the one-component protein (Fn or Ab) and the two-component proteins adjusted to different molar ratios of Fn to Ab at a fixed Fn concentration was investigated. The frequency shift (Δf; Hz) and the dissipation energy shift (ΔD) were measured with the QCM-D technique, and the viscoelastic changes of adlayers were evaluated by the saturated ΔD/Δf value and the Voigt-based viscoelastic model. For the adsorption of the one-component protein, the Fn adlayer showed a larger mass and higher viscoelasticity than the Ab adlayer, indicating the higher affinity of Fn on HAp. For the adsorption of the two-component proteins, the viscoelastic properties of the adlayers became elastic with increase in Ab concentration, whereas the adsorption mass was similar to that of Fn in the one-component solution regardless of the Ab concentration. The specific binding mass of the Ab antibody to the adlayers increased with increase in Ab concentration, whereas that of the Fn antibody decreased. Therefore, Fn preferentially adsorbs on HAp and Ab subsequently interacts with the adlayers, indicating that the interfacial viscoelasticity of the adlayers was dominated by the interaction between Fn and Ab.     

利用染料吸附评价活性炭纤维结构的初步研究

研究了一系列不同结构的活性炭纤维对水溶液中碘、酚及亚甲基蓝、结晶紫、二甲酚橙的吸附特征。揭示了染料在活性炭纤维上吸附量的大小,明显受活性炭纤维孔宽的屏蔽作用（分子筛效应）的影响。初步提出可利用染料吸附特征与活性炭纤维的孔宽和染料分子的几何尺寸的相关性,简便地评价活性炭纤维的孔结构和液相吸附性能。     

Study the adsorption of phenol from aqueous solution on hydroxyapatite nanopowders

In this study, the hydroxyapatite (HAp) nanopowders prepared by chemical precipitation method were used as the adsorbent, and the potential of HAp nanopowders for phenol adsorption from aqueous solution was studied. The effect of contact time, initial phenol concentration, pH, adsorbent dosage, solution temperature and adsorbent calcining temperature on the phenol adsorption, and the adsorption kinetic, equilibrium and thermodynamic parameters were investigated. The results showed that the HAp nanopowders possessed good adsorption ability to phenol. The adsorption process was fast, and it reached equilibrium in 2h of contact. The initial phenol concentration, pH and the adsorbent calcining temperature played obvious effects on the phenol adsorption capacity onto HAp nanopowders. Increase in the initial phenol concentration could effectively increase the phenol adsorption capacity. At the same time, increase in the pH to high-acidity or to high-alkalinity also resulted in the increase in the phenol adsorption capacity. Increase in the HAp dosage could effectively increase the phenol adsorption percent. However, the higher calcining temperature of HAp nanopowders could obviously decrease the adsorption capacity. The maximum phenol adsorption capacity was obtained as 10.33mg/g for 400mg/L initial phenol concentrations at pH 6.4 and 60 degrees C. The adsorption kinetic and the isotherm studies showed that the pseudo-second-order model and the Freundlich isotherm were the best choices to describe the adsorption behaviors. The thermodynamic parameters suggested that the adsorption of phenol onto HAp was physisorption, spontaneous and endothermic in nature.