亲水性聚氨酯复合材料的制备与表征

选用湿态纳米羟基磷灰石（HA）与脂肪族聚氨酯（PU）为原料,采用溶液共混法和溶剂挥发法制备了亲水性羟基磷灰石/聚氨酯（HA/PU）纳米复合材料,并采用SEM、吸水实验和力学实验等方法对该复合材料的形貌和性能进行了研究。结果表明磷灰石晶体以纳米状态均匀地分布在PU基质中,过高含量的纳米HA易使纳米粒子团聚,不利于其在PU基体中的均匀分散;在制备PU的多元醇原料中引入亲水性较强的聚乙二醇,可提高PU表面和整体的亲水性;随着硬段含量的增加,复合材料的拉伸强度和弹性模量呈上升趋势,断裂伸长率下降;随着软段中聚乙二醇含量的升高,弹性模量大幅下降,拉伸强度和断裂伸长率先升高后下降;纳米HA的添加可同时提高复合材料的拉伸强度和断裂伸长率,当纳米HA的质量分数为30%时,复合材料的综合力学性能达到最佳。     

表面接枝处理的n-HA充填PLGA等温结晶行为的研究

应用示差扫描量热计（DSC）研究了用低分子量聚乳酸（PDLLA）接枝与未接枝两种处理的纳米羟基磷灰石（n-HA）对聚乙丙交酯（PLGA）等温结晶行为及熔融行为的影响,采用Avrami方程处理其等温结晶过程,计算结晶动力学参数;同时用配带热台的偏光显微镜（POM）研究了其结晶的晶核形态。结果表明该体系等温结晶行为可以用Avrami方程来描述;加入n-HA的两种复合材料及PLGA其结晶最快的温度都是110℃,且都是随着结晶温度的提高结晶速率变慢,但接枝的n-HA对提高PLGA基体的结晶速率、熔点及结晶活化能都比未接枝处理的要小。偏光显微镜研究得出加入n-HA的两种复合材料及PL-GA其球径形态相似,且都随温度升高而使结晶速度降低,但加入未接枝的n-HA比接枝后的结晶更快。以上结果说明接枝处理后的n-HA提高了两相界面结合,因而n-HA的异相成核能力比未接枝处理的要差。     

Chemical,thermal, and mechanical properties and ultraviolet transmittance of novel nano-hydroxyapatite/polyethylene terephthalate milk bottles

Polyethylene terephthalate (PET)/nano-hydroxyapatite (nHAp) composite granules were obtained using twin-screw extruder. Preforms were prepared by injection molding and then PET/nHAp bottles were produced by blow molding. For PET bottles with nHAp, the migration amounts of carboxylic acid (COOH), acetaldehyde (AA), diethylene glycol (DEG), and isophthalic acid (IPA); glass transition temperature (T_g); melting temperature (T_m); and the maximum crystallization temperature (T_cry) were measured. The load-carrying capacity, burst strength, stress cracking, and regional material distribution tests were carried out on the bottles. X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, differential scanning calorimetry, and ultraviolet transmittance analyses were conducted to explain the changes in mechanical, chemical, physical properties, and light transmission of bottles. It was found out that the COOH amount increased and the AA content decreased with increasing nHAp amount. On the other hand, no change was observed in the amounts of DEG and IPA. Although the mechanical properties such as load-carrying capacity and burst strength of the bottles have improved, it has been determined that the standard environmental stress crack resistance test procedure cannot be applied to such a composite. Experimental findings indicate that nHAp disrupts the chemical structure of PET and it isolates harmful chemicals such as AA by forming intermolecular bonds. Moreover, with the addition of up to 0.8% nHAp, PET bottles block the light transmission approximately 80% within 400–700 nm wave length zone. The study demonstrates that the PET/nHAp composite bottles can be used in the food industry, particularly in the packaging of milk and milk products which are vulnerable to light exposure.     

纳米羟基磷灰石及其复合材料技术进展

介绍了纳米羟基磷灰石制备和掺杂技术,以及纳米羟基磷灰石复合材料,包括它们在组织工程支架材料、缓控释药物载体、靶向药物传递及环境功能材料等方面的制备技术和应用,显示纳米羟基磷灰石及其复合材料在生物医学领域将会有良好发展前景。     

Zein/polyvinyl alcohol-based electrospun nanofibrous films reinforced with nano-hydroxyapatite for efficient Cu(II) adsorption

To solve the problem of the presence of heavy metals in water causing water pollution, the biodegradable film based on zein/polyvinyl alcohol (PVA) with the incorporation of nano-hydroxyapatite (nHAP) was fabricated through an electrospinning technique. The copper ion was taken as the representative of heavy metal ions in this study. The result showed that the incorporated nHAP nanoparticles were dispersed within the zein/PVA matrix, and strong hydrogen bonding interactions were formed between the filler and matrix, improving the hydrophobicity of the nanofibrous films and maintaining thermal stability. The adsorption mechanism was analyzed by fitting the adsorption process with pseudo-first-order model and pseudo-second-order model. Based on the ion exchange effect, electrostatic interaction, and complexation, the adsorption capacities of nanofibrous films for Cu(II) were significantly increased after adding nHAP. When the nHAP content was 20 wt.%, the Cu(II) adsorption capacity reached up to 23.86 mg/g, and the adsorption efficiency was 13.94% higher than that of neat zein/PVA nanofibers. This work suggests the potential of the electrospun zein/PVA/nHAP nanofibrous films as desirable eco-friendly materials in metal removal applications.     

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。     

溶胶-凝胶法制备纳米羟基磷灰石的研究进展

本文综述了溶胶-凝胶法的基本原理,以及国内溶胶-凝胶法制备纳米羟基磷灰石的研究进展,提出了有待解决的问题。     

纳米掺锶羟基磷灰石的制备及其吸附性能研究

采用溶胶-凝胶-超临界流体干燥法制备了粒径在100 nm以下的纳米掺锶羟基磷灰石(SrHAP),以牛血清白蛋白(BSA)为吸附目标,研究了纳米SrHAP的吸附性能.结果发现在偏酸性条件下,纳米SrHAP比纳米HAP对BSA的吸附量大,表明掺锶后吸附性能提高;但在碱性条件下,纳米SrHAP对BSA的吸附量减小.纳米SrHAP对BSA的吸附是个快速吸附过程,增加Sr/[Ca Sr]原子比XSr和BSA的起始浓度有利于吸附,升高温度不利于吸附.     

磷酸钙在纳米羟基磷灰石／硅橡胶复合材料表面的仿生合成

将纳米羟基磷灰石，硅橡胶复合材料浸泡于模拟体液（SBF）中仿生合成了磷酸钙，利用IR、XRD、ICP和SEM等测试手段对表面沉积物进行表征．结果表明：在模拟体液中浸泡后，复合材料表面形成了分布均匀的以羟基磷灰石为主要成分的晶粒，表面羟基磷灰石的比例得到提高，生物学性能得以进一步改善；表明纳米羟基磷灰石，硅橡胶复合材料是一种生物活性材料．     

Composites of Nano-hydroxyapatite and Poly（ε-caprolactone） Composite Fibers by Electrospinning

用水热法合成的棒状纳米羟基磷灰石（nHA）,引发ε-己内酯（ε-CL）开环聚合得到nHA-PCL复合材料。用静电纺丝法分别制备了聚己内酯（PCL）、nHA/PCL共混材料和nHA-PCL复合材料的3种电纺纤维膜。通过FT-IR、DSC、SEM、TGA和拉伸试验机表征了样品的结构、热性能和力学性能。结果表明：nHA-PCL电纺膜的结晶性能优于nHA/PCL材料,且热稳定性和力学性能都优于其他两种膜,nHA-PCL电纺膜的完全分解温度为420°C,拉伸强度和断裂伸长率分别达到28.2MPa和55.6%。3种膜的纤维直径均小于500 nm,nHA-PCL电纺膜的纤维表面比较粗糙。在人体仿生液中诱导矿化4 d后,nHA-PCL电纺膜纤维表面出现磷灰石沉积,而纯PCL和共混nHA/PCL电纺膜的纤维表面沉积的磷灰石很少,nHA-PCL复合电纺膜具有较好的诱导成骨性能。