Silver Chloride Loaded Mesoporous Silica Particles and Their Application in the Antibacterial Coatings on Denture Base

Thiol-functionalized MCM-41 type mesoporous silica particles（MSPs） were prepared and loaded with silver chloride to act as antibacterial agents. The antibacterial activity of the silver chloride loaded MSPs（AgCI-MSPs） was evaluated by the minimum bactericidal concentration（MBC） against Candida albieans（ATCC 10231）. The AgC1-MSPs with the highest antibacterial activity were then dispersed in hybrid coatings with different mass ratios to fabricate antibacterial coatings. The antibacterial activity of the coatings was tested against Candida albicans{ATCC 10231） and Streptococcus mutans（ATCC 25175）. The resulting antibacterial coatings exhibited high antibacterial activity, good adhesion to the substrate and high hardness.     

中空纳米二氧化硅微球的制备及表征

本文介绍了一种制备中空纳米二氧化硅微球的新方法。利用模板首先合成介孔纳米二氧化硅微球,再用水热反应法,成功制备了非功能化和巯基、氨基功能化中空纳米二氧化硅微球。利用透射电子显微镜,热重分析等手段对其形貌进行了表征。另外,对中空介孔纳米二氧化硅微球的形成机制进行了探讨。     

中空介孔硅球原位接枝聚苯胺及其pH响应性药物控制释放行为

通过原位化学氧化聚合的方法,在中空介孔二氧化硅纳米粒子表面成功接枝上了聚苯胺(HMSsPANI).借助透射电镜(TEM)、红外光谱(FTIR)、紫外可见吸收光谱(UV-Vis)、氮气脱附吸附等温测试(BET)、热失重(TGA)、小角粉末衍射(XRD)和zeta电位测试等手段表征了其结构性质.通过循环伏安曲线研究,发现HMSs-PANI分散体系在不同pH条件下具有电化学活性的转变性质,证实了HMSs-PANI在酸性条件下能够进行有效的掺杂从而具有电化学活性.最后用HMSs-PANI来负载抗癌药物盐酸阿霉素(DOX),其展现了良好的酸性pH可控释放行为,在pH=7.4时,22 h后仅有15%的药物累计释放量.在pH=5的条件下,22 h后累计释放量达到44%,而在pH=4条件且同样时间之下,释放量为60%.总之,合成的HMSs-PANI酸响应药物控制释放体系在药物传输领域具有潜在应用.     

中空介孔二氧化硅锚固聚偕胺肟吸附Cr(Ⅵ)

以硝酸铈铵为引发剂, 在自制的中空介孔二氧化硅(HMS)的空腔和通道内引发丙烯腈自由基聚合, 并将其氰基偕胺肟化, 用于制备具有吸附Cr(Ⅵ)的廉价有机无机复合吸附材料—中空介孔二氧化硅锚固聚偕胺肟. 通过傅里叶变换红外光谱(FTIR)、 扫描电子显微镜(SEM)及N₂吸附-脱附比表面分析对中空介孔二氧化硅锚固聚偕胺肟进行表征. 结果表明, 制备的中空微球直径约为400 nm, 其壁上孔径约为11.0 nm, 比表面积约为431 m²/g, 锚固聚偕胺肟后中空微球壁上孔道直径约为4.6 nm, 比表面积降低为347 m²/g. HMS锚固的聚偕胺肟对重铬酸钾溶液中铬的吸附量高达0.46 mmol/g, 吸附过程中伴随化学反应, 符合伪二级动力学模型, 可用作废水处理中重金属离子的高效廉价吸附材料.     

介孔氧化硅球负载钴基催化剂在费托合成中的应用

以介孔氧化硅空心球(HMSS)为载体, 采用双溶剂法浸渍硝酸钴溶液制备了高分散度的钴催化剂, 并表征了催化剂中Co3O4颗粒的负载情况和费托(F-T)反应性能. 结果表明: Co3O4颗粒在介孔硅球孔道内形成100～200 nm左右分散良好的簇团, 将催化剂压碎和刻蚀后的透射电子显微镜(TEM)证实, 这些簇团是由尺寸约为10～15 nm大小均匀的Co3O4单分散颗粒组成, 这些单分散颗粒锚定在介孔硅球孔道内, 彼此之间被相邻孔壁隔开; 催化剂中钴-硅作用很弱, 在600 K下即可被还原; F-T反应评价表明, 所得产物保持了良好的烃分布, 主要集中于C5～C18烃, 选择性在60%左右, C5＋选择性达到80%以上.     

介孔SiO2负载的纳米金及其催化应用

金（Au）的催化作用已成为催化领域的前沿研究课题。本文综述了近年来采用不同方法制备介孔二氧化硅(MCM-41, MCM-48, SBA-15)负载的纳米Au催化剂以及在CO低温氧化、环己烯加氢和环己烷氧化等反应中的催化作用。讨论了影响纳米Au催化剂活性的相关因素, 包括载体的种类、表面性质、Au纳米颗粒的尺寸、分散度以及稳定性等。最后对各种制备纳米Au的方法进行了总结。     

Jeffamine聚醚胺改性合成介孔及超微孔氧化硅微球

通过对Jeffamine ED2003进行硬脂酸接枝,获得了一种在水溶液中能够进行自组装的新型聚醚酰胺高分子表面活性剂,命名为ED2003-fa-18.以ED2003-fa-18聚醚酰胺高分子表面活性剂为模板,以正硅酸乙酯(TEOS)为无机硅源,在酸性条件下水热合成了介孔及超微孔氧化硅微球.利用粉末X射线衍射(XRD)、N₂物理吸附、红外光谱(IR)、核磁共振波谱(¹H NMR)、扫描电镜(SEM)和透射电镜(TEM)等方法对合成样品进行了表征.研究结果表明,通过改变合成体系中表面活性剂的浓度,可控合成出了有序的介孔及超微孔氧化硅材料.当ED2003-fa-18的浓度为1wt%时,合成的材料为介孔氧化硅,样品的最可几孔径约为2.2 nm.当ED2003-fa-18的浓度从3wt%增加到7wt%时,样品的最可几孔径从1.98 nm减小到1.94 nm,得到的样品为超微孔氧化硅材料.样品的比表面积在500 m²·g^-1左右,孔体积在0.3 cm³·g^-1左右.由SEM照片可知,所合成的介孔及超微孔氧化硅材料均为由20~30 nm的球形纳米颗粒进一步团聚形成的2~4 μm的紧密堆积的实心微球.     

Jeffamine聚醚胺改性合成介孔及超微孔氧化硅微球

通过对Jeffamine ED2003进行硬脂酸接枝,获得了一种在水溶液中能够进行自组装的新型聚醚酰胺高分子表面活性剂,命名为ED2003-fa-18。以ED2003-fa-18聚醚酰胺高分子表面活性剂为模板,以正硅酸乙酯(TEOS)为无机硅源,在酸性条件下水热合成了介孔及超微孔氧化硅微球。利用粉末X射线衍射(XRD)、N₂物理吸附、红外光谱(IR)、核磁共振波谱(¹H NMR)、扫描电镜(SEM)和透射电镜(TEM)等方法对合成样品进行了表征。研究结果表明,通过改变合成体系中表面活性剂的浓度,可控合成出了有序的介孔及超微孔氧化硅材料。当ED2003-fa-18的浓度为1wt%时,合成的材料为介孔氧化硅,样品的最可几孔径约为2.2nm。当ED2003-fa-18的浓度从3wt%增加到7wt%时,样品的最可几孔径从1.98nm减小到1.94nm,得到的样品为超微孔氧化硅材料。样品的比表面积在500m²·g^-1左右,孔体积在0.3cm³·g^-1左右。由SEM照片可知,所合成的介孔及超微孔氧化硅材料均为由20~30nm的球形纳米颗粒进一步团聚形成的2~4μm的紧密堆积的实心微球。     

Advances in the Interfacial Assembly of Mesoporous Silica on Magnetite Particles

Interfacing magnetic particles with ordered mesoporous materials is an effective direction for the development of functional porous composite materials with rationally designed core–shell structures. Owing to the combined properties of magnetic nanoparticles and mesoporous silica (high surface area, large pore volume, porosity, and biocompatibility), core–shell magnetic mesoporous silica materials have generated tremendous interest in various disciplines, including chemistry, materials, bioengineering, and biomedicine. Interfacial assembly strategies enable the rational construction of magnetic mesoporous silica materials with well‐defined core–shell structure, morphology, pore parameters, and surface wettability, which can decisively influence their physical and chemical properties and thus improve their application performance. This Minireview summarizes recent progress in the synthesis of core–shell magnetic mesoporous silica and the adjustment of key parameters, including pore size, morphology, and pore orientation.     

Au@SiO_2中空微球的制备及催化性能

以天然高分子阿拉伯树胶(AG)为还原剂和稳定剂制备了金纳米粒子;将含有金纳米粒子(Au NPs)、阿拉伯树胶和氨水的溶液滴加到乙醇中形成AG-Au NPs复合胶团;利用正硅酸乙酯水解,在AG-Au NPs表面包覆二氧化硅壳层;通过简单水洗的方法得到了金纳米粒子@二氧化硅(Au@SiO_2)中空微球.采用透射电子显微镜(TEM)、X射线衍射仪(XRD)和氮气吸附实验等对Au@SiO_2中空微球进行表征.通过设计对比实验,证实阿拉伯树胶在中空结构形成过程中起到模板剂的作用.催化性能测试结果表明,所制备的Au@SiO_2中空微球在硼氢化钠还原亚甲基蓝的反应中表现出良好的催化活性和重复使用性.     

有序介孔氧化硅薄膜制备及其组装化学

本文综述了近年来利用有机模板法合成有序介孔二氧化硅薄膜的研究进展，重点阐述了两相界面外延生长和蒸发诱导自组装两种制备方法及其合成机理。此外，讨论了有序介孔二氧化硅薄膜的组装化学，包括金属元素掺杂，纳米粒子在介孔薄膜中的组装，以及有机物/二氧化硅纳米复合薄膜的制备，并对介孔二氧化硅薄膜未来的发展趋势做了展望。     

单分散介孔氧化硅纳米颗粒的制备及其在生物材料方面的应用

单分散介孔氧化硅纳米颗粒由于其自身的优点,在当前许多领域有着广泛的应用前景。本文综述了近十几年来单分散介孔氧化硅纳米颗粒的制备方法以及在生物材料方面的应用。在制备方法方面,根据其制备机理分为稀溶液法、微乳法、模板剂法以及向反应体系中加入不同的添加剂等方法,制备出分散性好、不同形态、孔径尺寸可调的介孔氧化硅纳米颗粒。在生物材料的应用方面,主要介绍了其在药物与生物活性分子的负载与控制释放、生物大分子的固载与分离、生物标记与临床诊断等方面的应用。     

磁性核壳介孔氧化硅微球的制备与应用

磁性核壳介孔氧化硅微球作为一种新型功能复合材料,已成为众多研究领域的一个研究热点。本文综述了近年来利用模板法合成磁性核壳介孔氧化硅微球的研究进展,重点阐述了溶胶-凝胶法和微乳液法在实心微球和中空微球制备中的应用。介绍了磁性介孔二氧化硅微球在蛋白质、DNA分离,靶向药物传输等生物医学上的应用以及磁性酸催化、加氢催化、纳米贵金属催化、光催化等催化领域的应用,并对其未来的发展趋势做了展望。     

Preparation,Antibacterial, and Antioxidant Activities of Silver/Chitosan Composites

Hybrid silver/chitosan composites were prepared and transmission electron microscopy (TEM) exhibited that silver nanoparticles were embedded in chitosan. The antibacterial activities of these composites were screened against Escherichia coli, Salmonella choleraesuis, Staphylococcus aureus, and Bacillus subtilis, which were much higher than that of chitosan. The TEM images of the treated bacteria showed that silver nanoparticles adhered to the bacterial cell surface and entered the interior of the cell, assuming that silver nanoparticles released from silver/chitosan composites could efficiently destroy the cell integrity of bacteria. Moreover, the composites exhibited higher antioxidant activity than chitosan based on the assessment of 2,2-diphenyl-1-picrylhydrazyl and hydroxyl radical scavenging and reducing power.     

Evaluation of Stability of Mesoporous Silica Nanoparticles and Their Further Formulation in Tablet Form

Mesoporous silica nanoparticles have been widely investigated as drug delivery systems. The present study evaluated physical stability of indomethacin loaded mesoporous MCM-41 nanoparticles. The size, polydispersity index, zeta-potential, and drug loading degree of nanoparticles were determined immediately after their preparation and after 6 months storage at 25°C in dry state. The results showed insignificant changes in these parameters, suggesting high stability of nanoparticles and loaded indomethacin. The nanoparticles were formulated in tablets by direct compression. The low friability indicated good resistance during handling and storage. The formulation of the nanoparticles into tablets decreased the initial release of indomethacin.     

MCM-41型介孔二氧化硅纳米颗粒的制备及其在DNA生物传感器中的应用

MCM-41型介孔二氧化硅纳米颗粒具有独特的结构特征和理化性质,能够与DNA、信号探针以及多种活性纳米颗粒结合,在DNA生物传感器中得到了广泛应用.其中,球形和薄膜形的MCM-41型介孔二氧化硅具有高负载量、孔口控释和高比表面积等优点,能有效装载各种信号探针、控制粒子的扩散以及固定大量活性纳米颗粒,可大大提高DNA生物...     

温度对介孔二氧化硅形貌和介相结构有序性的影响

1992年Kresge等科学工作者首次报道了一种新颖的介孔二氧化硅材料,介孔二氧化硅的合成及其性能表征引起了广泛的研究兴趣[1,2]。这种材料由于具有高比表面积(1000~1400m2·g-1)、孔道排列有序、孔径分布窄并可以在2~10nm范围内可调等优点,所以有望用于催化与吸附、化学传感、纳     

A Facile and Universal Method to Prepare Hydrophilic Molecularly Imprinted Microspheres by Encapsulating a Polymer in Hollow Mesoporous Silica Microspheres

Hydrophilic molecularly imprinted microspheres (MIP@SiO₂) for the adsorption of water‐soluble molecules in real aqueous samples were successfully synthesized. In this strategy, a molecular imprinted polymer (MIP) was encapsulated in the hollow core of hollow mesoporous silica (HMS) particles via a ‘ship‐in‐a‐bottle’ process. As the HMS shell contains plenty of Si‐OH groups, the as‐prepared microspheres proved to be hydrophilic and could be well dispersed in water. On the other hand, the MIP encapsulated in the HMS could specifically recognize small molecules with good binding efficiency through the mesoporous silica shell. Binding experiments in real aqueous solutions showed that the MIP@SiO₂ composites have excellent recognition ability for specific molecules. Thus, MIP@SiO₂ are highly promising alternatives to biological receptors with great potential for many analytical applications, such as environmental, food, and clinical analyses and other areas.     

荧光介孔二氧化硅纳米粒子的合成及药物运输

合成了荧光介孔二氧化硅纳米粒子（MSNs-FITC）,并研究了其在持续药物释放和生物示踪成像方面的应用。首先,采用一步法合成出MSNs-FITC,结合SEM、TEM、FT-IR、XRD和氮气吸附脱附等表征技术进行表征。其次,将抗癌药物阿霉素（DOX）负载到MSNs-FITC中。载药粒子的药物释放行为具有明显的pH依赖性,酸性环境加速释放速率。同时,体外细胞毒性测试表明MSNs-FITC具有良好的生物相容性。激光共聚焦扫描显微镜（CLSM）图像表明,MSNs-FITC可以进入细胞并具有剂量依赖性,流式细胞术分析（FCM）进一步证明了这一结果。     

Disulfide-crosslinked Poly(L-glutamic acid) Grafted Mesoporous Silica Nanoparticles and Their Potential Application in Drug Delivery

Poly(L-glutamic acid)(PLGA) was grafted onto the surface of mesoporous silica nanoparticles(MSN) via the ring opening polymerization of γ-benzyl-L-glutamate N-carboxyanhydride(BLG-NCA) and its subsequent deprotection of benzyl groups. The PLGA chains were cross-linked with cystamine, and thus forming a type of redox responsive drug delivery system(MSN-cPLGA). The structures were characterized by Fourier transform infrared spectrometry(FTIR), transmission electron microscopy(TEM) and energy disperse spectrometry(EDS), demonstrating that disulfide groups existed on the surfaces of MSN-cPLGA particles. The thermal gravimetric analysis(TGA) results show that the PLGA mass fraction is about 33.4% in the MSN-cPLGA hybrid. The in vitro drug release experiments showed that the MSN-cPLGA hybrid can realize the controlled release of model drugs(5-fluorouracil) in response to redox environment. Even 0.1 mmol/L dithiothreitol(DTT) can accelerate the drug release speed, and a concentration of 10.0 mmol/L DTT is higher enough to trigger the open of cross-linked PLGA network so as to realize rapid release of drugs. All the results demonstrate that the cross-linked PLGA chains on the surface of MSN could act as efficient gatekeepers to control the on-off of the pores, showing potential application in drug delivery system.