工艺条件对鱼鳞提取羟基磷灰石显微结构的影响

鱼鳞含有30％的无机质中绝大部分是羟基磷灰石,由于羟基磷灰石其良好的生物相容性,广泛应用于生物医用领域.本文讨论了不同浸泡时间和不同浓度的NaOH溶液对鱼鳞中的羟基磷灰石晶体结构的影响.通过X射线衍射和扫描电子显微镜分别对鱼鳞经过浸泡煅烧后产物的物相组成和显微结构进行了分析.结果表明,当鱼鳞经过1mol/L的NaOH溶液浸泡24h后,煅烧得到的羟基磷灰石的显微结构为较好的立方片状,而浸泡48h煅烧后的颗粒尺寸与鱼鳞浸泡12h和24h的相比偏小.     

生物医用纳米羟基磷灰石的研究进展

纳米羟基磷灰石既具有纳米材料的特性,又具有羟基磷灰石本身的特性,在生物医学领域具有非常广阔的应用前景.本文详细介绍了纳米羟基磷灰石的历史发展、制备方法、表面改性及其在生物医用材料领域的应用.     

纳米羟基磷灰石应用研究进展

羟基磷灰石是人体和动物骨骼的主要无机矿物成分,当羟基磷灰石的尺寸达到纳米级时将表现出一系列的独特性能。纳米羟基磷灰石具有良好的生物相容性和生物活性,是较好的生物材料,被广泛应用于骨组织的修复与替代技术,在生物医学领域具有非常广阔的应用前景。文章综述了纳米羟基磷灰石的应用研究,指出了目前纳米羟基磷灰石材料中存在的主要问题,并对纳米羟基磷灰石的发展前景进行了展望。     

鱼鳞中胶原蛋白的提取工艺研究

用酸提取法从鲫鱼中提取胶原蛋白,用不同浓度的盐酸作为脱钙溶液,以0.5 mol/L乙酸—乙酸钠缓冲溶液提取其胶原蛋白。单因素分析与正交试验结果表明:提取温度为6~10℃时,最佳提取条件为固液比1∶20,提取时间每次1.5 h,脱钙酸浓度为0.5 mol/L,脱钙时间3 h,胶原蛋白提取率为0.773%。     

聚乙烯醇改性纳米羟基磷灰石的制备

本文以四水硝酸钙和磷酸氢二铵为原料,通过化学沉淀法合成了纳米羟基磷灰石(HA)粉,并引入聚乙烯醇(PVA)做HA的有机改性剂,制备了有机改性的羟基磷灰石纳米粉。用X射线衍射(XRD)、红外光谱(FTIR)和透射电镜(TEM)对HA粉体进行了分析表征。结果表明,引入聚乙烯醇做有机添加剂后,羟基磷灰石粉在700℃煅烧后的粒度在80nm左右。     

生物水泥中羟基磷灰石的低温合成

通过各种不同于传统烧结方法的途径，首先在 温下合成活性磷酸钙，再通过不同的实验条件生成活性羟基磷灰石水化产物，采用ＸＲＤ和ＳＥＭ技术分析了作为生物水泥的几个矿相间的关系。研究认为：Ｃａ５（ＰＯ４）３．ＯＨ、Ｃ３Ｆ．ｘＨ２Ｏ和Ｃａ（ＯＨ）２矿相可能共生。从而进一步提出活性生物水泥相组成的初步设想。     

锶掺杂纳米羟基磷灰石的制备

骨缺损的治疗是临床研究中的一项重大挑战,在天然骨骼中发现的各种人体必需元素中,锶是一种非常特殊的元素。在人体中,锶具有很强的亲骨性。锶掺杂后的纳米羟基磷灰石,与未掺杂的羟基磷灰石相比表现出增强的促成骨细胞分化活性。     

纳米羟基磷灰石粉体的制备工艺

简要介绍了羟基磷灰石的结晶结构和其理化性质,综合论述了纳米羟基磷灰石的制备工艺及其原理。同时,对常用制备方法进行了比较,指出了目前纳米羟基磷灰石粉体制备存在的问题及今后的发展方向。     

纳米羟基磷灰石制备方法的研究进展

介绍了目前纳米羟基磷灰石的制备方法,重点阐述了化学沉淀法制备纳米羟基磷灰石的研究情况,并对纳米羟基磷灰石整个行业的发展做出了展望。     

针状缺钙羟基磷灰石涂层的烧结特征及磷酸氢钙相的影响

研究了Ｔｉ６Ａｌ４Ｖ表面针状缺钙羟基磷灰石涂层在４５０－９８０℃空气中烧结后的相组成和显微主磷酸氢钙相的影响,分析了缺钙羟基磷灰石的高温分解行为。烧结过程不仅使Ｔｉ６Ａｌ４Ｖ表面形成致密的ＴｉＯ２保护膜,而且获得了对骨组织生长 有利的 式磷灰石＋β－磷酸三钙双相涂层结构。由此使涂层／基体系统的生物特性和力学性能同时得到改善。     

沉淀法制备羟基磷灰石反应条件控制研究

为了方便快速地获得高纯度羟基磷灰石,本研究以（NH4）2HPO4和Ca（NO3）.24H2O为原料,利用沉淀法制备纳米级羟基磷灰石粉末。对温度、pH值、分散剂添加比例、钙磷比、烧结温度等反应控制条件进行了研究,对钙磷比及烧结温度做了详细的讨论。结果表明：此法可以得到分散性、均匀性好,纯度高、颗粒小、晶形完整的纳米级羟基磷灰石。     

超临界CO_2提纯鱼油中二十碳五烯酸组分

<正>鱼油中含多种多烯脂肪酸,其中二十碳五烯酸（简称EPA,速记式20巧。3）具有降低胆固醇、抑制血栓形成等药理作用,而二十二碳六烯酸（简称DHA,速记式22:6。3）具有健脑等生理作用’“.日本已于1990年开发出含EPA乙酯>92％的心血管系新药.鱼油     

短棒状纳米羟基磷灰石的湿法合成及表征

通过简单湿法合成制备了短棒状纳米羟基石颗粒，粉体在不同的温度下进行了热处理，并用红外光谱、透射电镜及X射线衍射等实验手段对组织、结构及热稳定性进行了表征。研究表明，将适当比例的（NH4）2HPO4和Ca（NO3）2晶体混合、振荡、陈化后提纯、烘干，可制备出长约30－40nm，直径约10－20nm的短棒状纳米羟基灰石颗粒，这种颗粒结构与通常的针状结构相比更接近于人体骨磷灰石（长约40－60nm，宽约20nm）；该颗粒具有较好的热稳定性，600℃以下热处理后，颗粒结构、尺寸和形貌基本不变，分散性较好；900℃热处理后，颗粒明显长大并严重团聚。     

A COMPREHENSIVE APPROACH FOR MODELING SORPTION OF LEAD AND COBALT IONS THROUGH FISH SCALES AS AN ADSORBENT

Removal of lead and cobalt cations from both industrial and municipal water is of extreme importance for waste water disposal standards. Using fish scales as an adsorbent, 95% of the lead cations and 70% of the cobalt ions can be removed. The processes related to the removal of the cations include adsorption and precipitation. The effect of precipitation of the cations in a neutral medium (pH 7) is studied and is found to be insignificant. Although the effect of precipitation is negligible in the studied experimental runs, it may assume significance in a highly nonporous medium. As sorption dictates the interactions between the bulk and adsorbed phases, it is the most important factor influencing the transport of the chemical species through the medium. Mobility of the cations has extreme importance to overall sorption characteristics because of high adsorption coefficients of the fish scales. It can be further concluded that even at cation concentration levels of 1000 ppm, sorption behavior is insensitive to change. To investigate the nature of the sorption mechanism, a series of experimental runs was conducted using fish scales of the Gadus Morhua (Atlantic cod) and Lethrinus nebulosus (spangled emperor or shouairi) species as substrates. A simulation model based on the theory of surface excess with mechanical entrapment is developed in this study. Numerical simulation results demonstrate reasonable agreements with the experimental results. This study illustrates that variations of flow rates of the cations did have a considerable effect on breakthrough time intervals. An increase in flow rate led to earlier contaminant breakthrough. However, variance of the cation concentrations did not have a dominant effect on the corresponding breakthrough values. The effect of porosity of the adsorbents is observed, and it is determined it has a profound impact on adsorption phenomena. The dispersion parameter is found to be a function of porosity, and its effect was studied in relation to the flow rate of the bulk phase. A decrease in porosity of the adsorbent results in an increase of the retardation factor of the contaminant in bulk phase and an equivalent delay in the breakthrough interval. In order to study the adsorption characteristics by surface excess model, the pH parameter was maintained at a constant pH value of 7 for all the experimental runs. The adsorption coefficient (K) was coupled into the numerical model as a parameter independent of the pH values. The numerical simulations did fit reasonably well with the experimental data.

The surface excess theory has been tested in the past only for anionic solutions. The significance of this research is that this model has been applied for the first time with respect to a bio-adsorbent in relation to heavy metal cations. It is found to be suitable for describing adsorption behavior of metallic contaminants at neutral pH. For studying adsorption with respect to the pH variable, a different adsorption model based on, the Langmuir isotherm is proposed.     

A COMPREHENSIVE APPROACH FOR MODELING SORPTION OF LEAD AND COBALT IONS THROUGH FISH SCALES AS AN ADSORBENT

Removal of lead and cobalt cations from both industrial and municipal water is of extreme importance for waste water disposal standards. Using fish scales as an adsorbent, 95% of the lead cations and 70% of the cobalt ions can be removed. The processes related to the removal of the cations include adsorption and precipitation. The effect of precipitation of the cations in a neutral medium (pH 7) is studied and is found to be insignificant. Although the effect of precipitation is negligible in the studied experimental runs, it may assume significance in a highly nonporous medium. As sorption dictates the interactions between the bulk and adsorbed phases, it is the most important factor influencing the transport of the chemical species through the medium. Mobility of the cations has extreme importance to overall sorption characteristics because of high adsorption coefficients of the fish scales. It can be further concluded that even at cation concentration levels of 1000 ppm, sorption behavior is insensitive to change. To investigate the nature of the sorption mechanism, a series of experimental runs was conducted using fish scales of the Gadus Morhua (Atlantic cod) and Lethrinus nebulosus (spangled emperor or shouairi) species as substrates. A simulation model based on the theory of surface excess with mechanical entrapment is developed in this study. Numerical simulation results demonstrate reasonable agreements with the experimental results. This study illustrates that variations of flow rates of the cations did have a considerable effect on breakthrough time intervals. An increase in flow rate led to earlier contaminant breakthrough. However, variance of the cation concentrations did not have a dominant effect on the corresponding breakthrough values. The effect of porosity of the adsorbents is observed, and it is determined it has a profound impact on adsorption phenomena. The dispersion parameter is found to be a function of porosity, and its effect was studied in relation to the flow rate of the bulk phase. A decrease in porosity of the adsorbent results in an increase of the retardation factor of the contaminant in bulk phase and an equivalent delay in the breakthrough interval. In order to study the adsorption characteristics by surface excess model, the pH parameter was maintained at a constant pH value of 7 for all the experimental runs. The adsorption coefficient (K) was coupled into the numerical model as a parameter independent of the pH values. The numerical simulations did fit reasonably well with the experimental data.

The surface excess theory has been tested in the past only for anionic solutions. The significance of this research is that this model has been applied for the first time with respect to a bio-adsorbent in relation to heavy metal cations. It is found to be suitable for describing adsorption behavior of metallic contaminants at neutral pH. For studying adsorption with respect to the pH variable, a different adsorption model based on, the Langmuir isotherm is proposed.     

湿法合成羟基磷灰石生物陶瓷材料的研究

本文主要研究了羟基磷灰石生物陶瓷材料的湿法制备工艺及其性状，通过IR、DSC／TG和XRD等测试手段分析，得出了湿法合成HAP的最佳工艺条件，热处理到700℃可以制备高纯度的羟基磷灰石生物陶瓷材料。     

TZP增韧HA复合材料的微观结构

用透射电子显微镜对四方氧化锆多晶（ZTP）增韧羟基磷灰石（HA）复合材料的微观相结构进行了观察与分析。结果表明,材料的相组成中,既有HA晶体,还有HA晶体在高温、高压成型过程中发生分解反应产生的磷酸三钙（Ca3(PO4)2晶体和磷酸二钙（Ca2P2O7)晶体;同时,样品中还观察到了三种晶形的氧化锆（ZrO2)：即立方（ZrO2)、四方ZrO2和单斜ZrO2,说明材料内部发生了t-ZrO2（高温型）→m-ZrO2（低温型）的马氏体相变。除此以外,还出现了CaZrO3相,CaZrO3相的形成是HA晶体分解出的CaO与ZrO2相互反应的结果。     

羟基磷灰石生物陶瓷的成型研究

在适宜的条件下，用化学沉淀法合成羟基磷灰石，加以不同粘合剂，并通过干压使其成型，控制不同温度将其烧结成陶瓷。简单分析烧结温度、时间及粘合剂等对HAP陶瓷成型的影响。结果表明：1100℃和3h是HAP生物陶瓷较佳的烧结温度和烧结恒温时间；比较之下，聚乙烯醇对HAP的干压成型工艺较适宜。     

水热处理对共沉淀法制备羟基磷灰石晶粒尺寸的影响

以硝酸钙和磷酸氢二氨为原料,以NH4 -NH3·H2O为缓冲体系控制pH为11.0,在40,70 ℃,采用共沉淀法合成了羟基磷灰石(hydroxyapatite,HAP).研究了120℃水热处理控制氨水快速挥发对HAP的晶粒尺寸和形貌的影响.采用X射线衍射分析HAP晶粒尺寸,透射电镜分析HAP的晶体表面形貌.结果表明:经水热处理后,40℃合成的HAP晶粒变大,而在70℃合成的HAP晶粒变小.HAP合成后,先静置再水热处理可得到更小的晶体.氨浓度对水热处理后HAP的晶粒尺寸影响不大.在上述各种制备条件下得到了分散性较好的棒状HAP纳米颗粒.