一步溶剂热法合成锶掺杂羟基磷灰石超长纳米线（英文）

羟基磷灰石超长纳米线可用于构建不同种类的生物材料,如高柔性生物医用纸和弹性多孔骨缺损修复支架,在生物医学领域具有良好的应用前景。锶元素作为一种微量元素,在骨代谢过程中起着重要作用。本研究通过一步溶剂热法合成了具有不同锶掺杂量的羟基磷灰石超长纳米线;研究了不同锶掺杂量对羟基磷灰石超长纳米线的形貌和物相的影响。所制备的锶掺杂羟基磷灰石超长纳米线具有高柔韧性和超长一维纳米结构。能量色散谱、X射线粉末衍射和傅里叶变换红外光谱分析表明,锶元素成功地掺杂到了羟基磷灰石超长纳米线中。本研究发展的制备方法可以制备锶/(锶+钙)摩尔比从0到100%任一比例的锶掺杂羟基磷灰石超长纳米线,大幅拓展了羟基磷灰石超长纳米线在骨缺损修复和牙科修复等生物医学领域中的应用。     

新型无机耐火纸

新型无机耐火纸是以羟基磷灰石超长纳米线作为原料制备而成的, 具有优良的生物相容性、环境友好、物理强度性能好、柔韧性高、耐高温、不燃烧、可用于书写和彩色打印, 有望用于档案等重要文件的长久保存。目前, 已制备出具有多种功能和用途的羟基磷灰石超长纳米线基新型纸张, 包括抗菌耐火纸、防水耐火纸、荧光耐火纸、耐高温标签纸、光(电)缆用阻燃耐火包带、快速检测试纸、生物医用纸、高效过滤纸等。新型无机耐火纸在特种纸、吸附过滤、生物医学、隔热、耐高温、环境保护、能源等领域展现出广阔的应用前景。本文综述了最近几年来新型羟基磷灰石超长纳米线基耐火纸研究取得的一些重要进展, 并且对该新型无机耐火纸未来的应用和产业化进行了展望。     

羟基磷灰石超长纳米线/植物纤维纳米复合“宣纸”及其防霉性能（英文）

宣纸是中国书画作品必不可少的载体,具有优良的耐久性和防霉性能,因此赢得了"纸中之王"的美誉。2009年,宣纸被联合国教科文组织列入《人类非物质文化遗产代表作名录》。羟基磷灰石具有优良的生物相容性,环境友好,白度高,是一种具有良好应用前景的生物材料。羟基磷灰石超长纳米线具有高柔韧性,可用于构建具有不同功能的新型耐火纸。本研究发展了一种新型纳米复合"宣纸",由羟基磷灰石超长纳米线和植物纤维复合制成。所制备的纳米复合"宣纸"的白度随着羟基磷灰石超长纳米线含量增加而得到提高,当羟基磷灰石超长纳米线重量比为25%时,其白度为76.1%,高于商品生宣纸(71.9%)或商品熟宣纸(70.3%)。采用三种霉菌(球毛壳霉菌、长枝木霉菌、黑曲霉菌)研究了新型纳米复合"宣纸"的抗霉菌性能。实验结果显示,与传统宣纸相比,所制备的纳米复合"宣纸"的防霉性能得到显著改善,与空白样品和商品宣纸相比,纳米复合"宣纸"对霉菌的生长具有更好的抑制能力,在其表面三种霉菌的生长速率明显较低,并且随着羟基磷灰石超长纳米线含量的增加而降低。在恒温恒湿箱内培养过程中,商品宣纸表面生长出霉菌,但是纳米复合"宣纸"表面上没有观察到明显...     

羟基磷灰石超长纳米线/植物纤维纳米复合“宣纸”及其防霉性能

宣纸是中国书画作品必不可少的载体, 具有优良的耐久性和防霉性能, 因此赢得了“纸中之王”的美誉。2009年, 宣纸被联合国教科文组织列入《人类非物质文化遗产代表作名录》。羟基磷灰石具有优良的生物相容性, 环境友好, 白度高, 是一种具有良好应用前景的生物材料。羟基磷灰石超长纳米线具有高柔韧性, 可用于构建具有不同功能的新型耐火纸。本研究发展了一种新型纳米复合“宣纸”, 由羟基磷灰石超长纳米线和植物纤维复合制成。所制备的纳米复合“宣纸”的白度随着羟基磷灰石超长纳米线含量增加而得到提高, 当羟基磷灰石超长纳米线重量比为25%时, 其白度为76.1%, 高于商品生宣纸(71.9%)或商品熟宣纸(70.3%)。采用三种霉菌(球毛壳霉菌、长枝木霉菌、黑曲霉菌)研究了新型纳米复合“宣纸”的抗霉菌性能。实验结果显示, 与传统宣纸相比, 所制备的纳米复合“宣纸”的防霉性能得到显著改善, 与空白样品和商品宣纸相比, 纳米复合“宣纸”对霉菌的生长具有更好的抑制能力, 在其表面三种霉菌的生长速率明显较低, 并且随着羟基磷灰石超长纳米线含量的增加而降低。在恒温恒湿箱内培养过程中, 商品宣纸表面生长出霉菌, 但是纳米复合“宣纸”表面上没有观察到明显的霉菌生长。预期所制备的纳米复合“宣纸”有助于书画艺术品的长久安全保存, 在书法和绘画艺术中具有良好的应用前景。     

水热制备锌、硅、镁、铁等元素掺杂羟基磷灰石及其表征

微量元素掺杂是赋予羟基磷灰石材料更多生物学功能的一条有效途径, 但不同元素的掺杂行为尚待进一步揭示。本研究使用并行水热合成方式, 制备分别含有锌、硅、镁、铁、锰、铜、锶、硒、钴的9种羟基磷灰石粒子, 并对其物理化学特性进行研究。结果表明, 元素掺杂显著改变了羟基磷灰石粒子的形貌和晶体生长方向, 但不改变其物相组成和官能团。晶体的(211)和(112)晶面衍射峰的强度均降低, 结晶度下降。元素实际掺杂效率分析结果显示锰>锌>镁>铁(三价)>锶>钴>铜>硒>硅, 与元素的离子半径大小相关。锰、锌、镁三种元素掺杂量较高, 因其离子半径与其替代的钙离子接近。铜元素掺杂效率较低是由于其在合成溶液中与氨产生络合作用, 硅元素和硒元素则因几何结构和电荷(SiO₃^2-、SeO₃^2-/PO₄^3-)差异导致掺杂率低。本研究揭示了掺杂行为与离子特性之间的联系, 为功能化羟基磷灰石的设计和开发提供有益的参考基础。     

羟基磷灰石超长纳米线/植物纤维纳米复合"宣纸"及其防霉性能

宣纸是中国书画作品必不可少的载体,具有优良的耐久性和防霉性能,因此赢得了"纸中之王"的美誉.2009年,宣纸被联合国教科文组织列入《人类非物质文化遗产代表作名录》.羟基磷灰石具有优良的生物相容性,环境友好,白度高,是一种具有良好应用前景的生物材料.羟基磷灰石超长纳米线具有高柔韧性,可用于构建具有不同功能的新型耐火纸.本...     

一步法合成锶离子掺杂羟基磷灰石多孔微球

羟基磷灰石(HA)多孔微球具有优异的生物学性能和流动性,被广泛用作骨填充材料、药物缓释载体等,发展前景十分广阔。掺杂锶后的HA表现出更强的促成骨细胞分化活性且可改善HA的降解性,然而如何高效地得到大尺寸的锶掺杂HA多孔微球是一大挑战。鉴于此,本工作以无水SrCl_2·6H_2O和(NH_4)_2HPO_4的水溶液为原料,尿素为pH调节剂,L-谷氨酸(Glu)为生长调控剂,采用水热均相沉淀法一步合成了锶离子掺杂的羟基磷灰石多孔微球。重点研究了锶离子掺杂量对所得产物的物相和微观形貌的影响,以期为离子掺杂型HA多孔微球的制备提供实验依据。研究表明,当锶掺入量n(Sr)/n(Sr+Ca)=0.01时,水热180℃反应10 h,可以得到形貌较规则均一的锶离子掺杂HA多孔微球。     

硅替代纳米羟基磷灰石的研究进展

硅元素掺杂羟基磷灰石可有效提高移植骨组织生物活性和生物相容性,在骨修复材料领域有着广泛的研究。概述了硅元素在骨修复材料中的作用,硅替代纳米羟基磷灰石粉体的制备、表征方法、替代机理及硅替代羟基磷灰石生物陶瓷在体内、体外实验中的最新研究成果,同时综述了硅替代羟基磷灰石目前存在的一些问题和其在骨修复材料方面的发展前景。     

羟基磷灰石微球的制备及生物医学应用

羟基磷灰石微球具有独特的球形结构,形态规则,流动性好,比表面积大,表现出良好的生物相容性和生物活性,在生物医学领域有着广泛的应用.总结了羟基磷灰石微球的不同制备方法,如模板法、水热法、喷雾干燥法、微乳液法、沉淀法等,分析了不同制备方法对羟基磷灰石微球形貌、尺寸、结晶度等的影响,讨论了不同方法下羟基磷灰石微球形成机理.最...     

钛掺杂对羟基磷灰石烧结稳定性和晶粒尺寸的影响

采用化学沉淀法通过钛掺杂合成了不同钛掺杂量(0.2%~2.4%(质量分数))的羟基磷灰石纳米粉,研究了钛掺杂量对其烧结稳定性和晶粒尺寸的影响规律。结果表明,不同钛掺杂量对羟基磷灰石的烧结稳定性和晶粒尺寸有非常显著的影响。随着钛掺杂量的增加,羟基磷灰石的晶格结构发生变化,a、c轴尺寸及其晶胞体积都在增加,并且和钛掺杂量成正比。在1 000~1 200℃烧结,不同钛掺杂量羟基磷灰石均未发生分解,表明钛掺杂抑制了羟基磷灰石的高温分解,提高了它的烧结稳定性。同时,钛掺杂有效限制了烧结过程中羟基磷灰石晶粒的长大,0.8%(质量分数)钛掺杂羟基磷灰石晶粒尺寸较纯羟基磷灰石晶粒尺寸明显细化。     

Development of an on-line flow injection Sr/matrix separation method for accurate, high-throughput determination of Sr isotope ratios by multiple collector-inductively coupled plasma-mass spectrometry

This work introduces a newly developed on-line flow injection (FI) Sr/Rb separation method as an alternative to the common, manual Sr/matrix batch separation procedure, since total analysis time is often limited by sample preparation despite the fast rate of data acquisition possible by inductively coupled plasma-mass spectrometers (ICPMS). Separation columns containing approximately 100 muL of Sr-specific resin were used for on-line FI Sr/matrix separation with subsequent determination of (87)Sr/(86)Sr isotope ratios by multiple collector ICPMS. The occurrence of memory effects exhibited by the Sr-specific resin, a major restriction to the repetitive use of this costly material, could successfully be overcome. The method was fully validated by means of certified reference materials. A set of two biological and six geological Sr- and Rb-bearing samples was successfully characterized for its (87)Sr/(86)Sr isotope ratios with precisions of 0.01-0.04% 2 RSD (n = 5-10). Based on our measurements we suggest (87)Sr/(86)Sr isotope ratios of 0.713 15 +/- 0.000 16 (2 SD) and 0.709 31 +/- 0.000 06 (2 SD) for the NIST SRM 1400 bone ash and the NIST SRM 1486 bone meal, respectively. Measured (87)Sr/(86)Sr isotope ratios for five basalt samples are in excellent agreement with published data with deviations from the published value ranging from 0 to 0.03%. A mica sample with a Rb/Sr ratio of approximately 1 was successfully characterized for its (87)Sr/(86)Sr isotope signature to be 0.718 24 +/- 0.000 29 (2 SD) by the proposed method. Synthetic samples with Rb/Sr ratios of up to 10/1 could successfully be measured without significant interferences on mass 87, which would otherwise bias the accuracy and uncertainty of the obtained data.     

Synthesis of Ca–Mg Apatite via a Mechanochemical Hydrothermal Process

Mixtures of calcium and magnesium hydroxides and calcium dihydrogenphosphate in various molar ratios were ground in water with a fine grinding machine, which features multiring grinding media. Mechanochemical amorphization of the mixtures occurs quickly by grinding. The mixtures, after grinding for 5, 20, and 60 min, were then subjected to hydrothermal treatment at 573 K for 24 h. The influence of Mg/(Mg + Ca) molar ratio on the thermal behavior of the mechanically activated powders and the structure of the final products has been investigated. The microhomogeneity of Mg, Ca, and P elements on the samples is enhanced by the mechanochemical treatment. A shift in the X-ray diffraction peaks was observed among the final products with different grinding times, presumably due to a partial substitution of calcium by magnesium.     

High-precision measurement of variations in calcium isotope ratios in urine by multiple collector inductively coupled plasma mass spectrometry

We describe a new chemical separation method to isolate Ca from other matrix elements in biological samples, developed with the long-term goal of making high-precision measurement of natural stable Ca isotope variations a clinically applicable tool to assess bone mineral balance. A new two-column procedure utilizing HBr achieves the purity required to accurately and precisely measure two Ca isotope ratios ((44)Ca/(42)Ca and (44)Ca/(43)Ca) on a Neptune multiple collector inductively coupled plasma mass spectrometer (MC-ICPMS) in urine. Purification requirements for Sr, Ti, and K (Ca/Sr > 10?000; Ca/Ti > 10?000?000; and Ca/K > 10) were determined by addition of these elements to Ca standards of known isotopic composition. Accuracy was determined by (1) comparing Ca isotope results for samples and standards to published data obtained using thermal ionization mass spectrometry (TIMS), (2) adding a Ca standard of known isotopic composition to a urine sample purified of Ca, and (3) analyzing mixtures of urine samples and standards in varying proportions. The accuracy and precision of δ(44/42)Ca measurements of purified samples containing 25 μg of Ca can be determined with typical errors less than ±0.2‰ (2σ).     

Fabrication of Cu2ZnSnS4 absorber layers with adjustable Zn/Sn and Cu/Zn+Sn ratios

In this work Cu₂ZnSnS₄ (CZTS) thin films were successfully prepared by sulfurization of spin coated CuO + ZnO precursor films under Sn and S ambience with different time. Precursor films were synthesized using air-stable inks consist of carboxylate-capped metal oxide nanoparticles. The composition, microstructure and properties of CZTS thin films prepared with different sulfurization time were investigated using inductively coupled plasma-mass spectrometry, X-ray diffraction, scanning electron microscopy, Raman spectroscopy and UV–vis–NIR spectroscopy. The inductively coupled plasma-mass spectrometry results show that mole ratios of Zn/Sn and Cu/(Zn + Sn) in the films can be adjusted by controlling sulfurization time. A composition of Cu/Zn + Sn = ~0.8, and Zn/Sn = ~1.2 can be reached after sulfurizating with proper time. The influence of element composition change was also studied in our work using X-ray diffraction and Raman scattering. Two laser sources of 325 and 514 nm were involved in the Raman scattering analyze in order to identify secondary phases such as ZnS and Cu_2?xS. The as-prepared CZTS films with a composition of Cu/Zn + Sn = ~0.8, and Zn/Sn = ~1.2 exhibit a direct optical band gap about 1.45 eV.     

Influence of strontium for calcium substitution in bioactive glasses on degradation,ion release and apatite formation

Bioactive glasses are able to bond to bone through the formation of hydroxy-carbonate apatite in body fluids while strontium (Sr)-releasing bioactive glasses are of interest for patients suffering from osteoporosis, as Sr was shown to increase bone formation both in vitro and in vivo. A melt-derived glass series (SiO₂–P₂O₅–CaO–Na₂O) with 0–100% of calcium (Ca) replaced by Sr on a molar base was prepared. pH change, ion release and apatite formation during immersion of glass powder in simulated body fluid and Tris buffer at 37°C over up to 8 h were investigated and showed that substituting Sr for Ca increased glass dissolution and ion release, an effect owing to an expansion of the glass network caused by the larger ionic radius of Sr ions compared with Ca. Sr release increased linearly with Sr substitution, and apatite formation was enhanced significantly in the fully Sr-substituted glass, which allowed for enhanced osteoblast attachment as well as proliferation and control of osteoblast and osteoclast activity as shown previously. Studying the composition–structure–property relationship in bioactive glasses enables us to successfully design next-generation biomaterials that combine the bone regenerative properties of bioactive glasses with the release of therapeutically active Sr ions.     

含镉羟基磷灰石的形成及其稳定性

采用液相共沉淀方法合成了不同镉摩尔含量X_Cd(即: Cd/(Ca+Cd))的镉羟基磷灰石. 通过XRD, FT-IR, FE-SEM, TG-DTG-DSC-MS和TCLP对产物的组成、形貌、热稳定性及化学稳定性进行了探讨. 结果表明, 随着X_Cd的增加, Cd²⁺进入到羟基磷灰石的晶格中依次形成Ca_3.9(Ca_4.7Cd_0.7)(PO₄)₆(OH)_1.8, Ca_3.8(Ca_4.1Cd_0.73)(PO₄_₆(OH)_1.8, Ca_3.6(Ca_4.5Cd_0.76)(PO₄)₆(OH)_1.6和Cd₅(PO₄)₃OH; 这些产物在500℃以下均可稳定存在, 且热稳定性随着X_Cd的增加明显提高; 毒性浸出结果显示, Cd²⁺能够进入到羟基磷灰石的晶格中, 但产物的化学稳定性不高.     

掺铜羟基磷灰石微球的制备及表征

铜作为人体含量第二的必需微量元素, 不仅在人体新陈代谢过程中起着重要作用, 同时还具有抗菌性。因此, 合成掺铜羟基磷灰石(Cu-HA)可望获得具有优良生物学性能兼具抗菌性能的生物陶瓷。本研究以硝酸钙、硝酸铜和磷酸氢二钠为原料, 采用水热合成法制备掺铜HA。采用扫描电镜、透射电镜、X射线衍射、红外和原子吸收光谱对样品进行表征。结果表明: 溶液体系中加入Cu²⁺后, Cu取代部分Ca进入HA晶格, 使其形貌由带状转变为花瓣状微球; 但Cu的掺入, 并不影响HA晶体结构; 当溶液中Cu/(Cu+Ca) 摩尔比高于0.05时, HA产物的热稳定性下降。     

Alginate hydrogels crosslinked with different strontium-calcium ratios as injectable scaffolds for bone tissue engineering

The easy loss of crosslinking ions in alginate can result in a structural collapse of the physiological environment, thereby losing its characteristics as a bone scaffold. Meanwhile, alginate lacks osteoconductive properties, which are necessary for ideal bone scaffolds. In this study, strontium (Sr) in combination with calcium (Ca) at different ratios were used as a crosslinking agent for the alginate to investigate the effect of Ca–Sr ratio on the physicochemical properties and biological preformation of alginate hydrogel. Here, Ca and Sr in different weight ratios (4:0, 3:1, 2:2, 1:3, and 0:4) were employed as crosslinking agents. The physicochemical properties of hydrogels, including pore size, elastic modulus, degradation rate and swelling ratio, could be effectively tuned by controlling the amount of Sr. The ion release experiment revealed a burst release of Sr²⁺ in the first day after crosslinking. However, after 3 days, the amount of Sr²⁺ release had significantly declined and was proportional to the total strontium initially introduced into the alginate. Meanwhile, the live/dead results exhibited higher cell viability for alginate with 2:2 Ca–Sr weight ratio. The alginate with 2:2 Ca–Sr ratio not only improved osteoblastic attachment, but also up-regulated the alkaline phosphatase activity, the expression of osteogenic marker genes, and relative growth factors. These findings indicate that alginate with 2:2 Ca–Sr ratio might be a promising scaffold for bone tissue engineering.

Graphical abstract

     

水热法合成锌空气电池氧还原二氧化锰催化剂

在180℃下通过改变K⁺与H⁺摩尔比使用水热法分别制备了δ-MnO₂, α-MnO₂和β-MnO₂ 纳米颗粒, K⁺与H⁺摩尔比分别为3.4、0.85和0.24。所合成的样品通过扫描电子显微镜(SEM), 粉末X射线衍射(XRD), 傅里叶变换红外光谱(FTIR), BET比表面分析, 热重分析(TG)和电化学方法表征。结果表明: K⁺与H⁺的浓度对产品的晶型、形貌以及比表面积有很大影响; 将这三种材料作为锌空电池的阴极材料时, δ-MnO₂与α-MnO₂的电化学性能明显优于β-MnO₂. 在–0.35 V下, δ-MnO₂、α-MnO₂和β-MnO₂的氧还原电流分别为56.28、56.01和40.88 mA/cm²。