氢氯噻嗪／MCM-41载药体系的制备与缓释作用研究

用微波辐射法合成介孔分子筛MCM-41，采用浸渍法将利尿药物氢氯噻嗪组装到介孔分子筛MCM-41孔道中，用XRD、低温N2吸附、IR对MCM-41及药物组装体进行了表征；研究了组装体的载药量、载药时间、在体外人工胃液中的释放等。结果显示合成的分子筛MCM-41具有规则的孔径结构，比表面积为1211m^2/g；分子筛MCM-41作为药物的载体具有较短的载药时间（t=26h），较大的载药量48％（m（药物）/优（载体）），较低的释放速率，表明制得了氢氯噻嗪／MCM-41缓释释放体系。     

氨丙基修饰MCM-41的制备及载药释药性能研究

用微波辅助水热法和共缩聚法分别制备了介孔分子筛MCM-41和氨丙基修饰的介孔分子筛MCM-41-(CH2)3NH2,将利尿药物氢氯噻嗪组装到两种材料中,用XRD、FT-IR、低温N2吸附、TG对分子筛及药物组装体进行表征,测定了组装体的载药量以及在人工胃液中的释放行为。结果显示MCM-41经氨丙基修饰后仍保持六方孔道结构,虽然孔径略有减小,但活性点位增加,仍有较大的载药量(38.23%),MCM-41和MCM-41-(CH2)3NH2载药体系均能实现缓释。修饰后释药速率进一步减慢,且随着氨丙基接枝量的增加递减,表明可通过氨丙基修饰量来调节释放速率。     

Eu-SSA-phen/MCM-41杂化发光材料的合成与表征

采用水热法合成改性MCM-41介孔分子筛;采用液相沉淀法合成了以磺基水杨酸及邻菲罗啉作为双配体的铕的配合物,找到其发光效果最好的配比,即n(Eu)∶n(SSA)∶n(phen)=1∶2∶1,并将发光效果最好的稀土配合物组装到改性后的MCM-41中,合成了稀土配合物(Eu)/改性MCM-41杂化发光材料,采用紫外光谱分析、元素分析、小角XRD、红外光谱、荧光光谱和TGA对其结构和荧光性质进行了研究。结果表明,组装体具有MCM-41典型结构并且在组装之后仍保留了MCM-41的孔道结构;其荧光光谱具有Eu3+的特征荧光发射,发光强度大于纯配合物。改性MCM-41后组装稀土配合物的发光效果更佳,热稳定性更好,更有利于实际应用。     

稀土配合物/改性MCM-41杂化发光材料的合成研究

采用水热法合成了改性MCM-41中孔分子筛;采用液相沉淀法合成了Eu(Phen)2(Pht)2Cl.H2O和Eu(Phen)2(Sal)(Pht)Cl.H2O两种稀土有机配合物。并将所制备的稀土有机配合物组装到改性MCM-41中,合成了稀土配合物(铕)/改性MCM-41杂化发光材料,采用小角XRD、红外光谱、荧光光谱和TEM、N2吸附-脱附对其结构和荧光性质进行了研究。结果表明,组装体具有MCM-41典型结构并且在组装之后仍保留了MCM-41的孔道结构;其荧光光谱具有Eu3+的特征荧光发射,发光强度大于纯配合物,更有利于实际应用。     

Tb（aspirin）3phen和MCM-41组装体的光谱研究

将MCM-41和客体Tb（aspirin）3phen进行组装，采用XRD、IR和PL进行了表征，探讨了主体McM-41和客体Tb（aspirin）1phen间的相互影响。MCM-41焙烧后再进行组装，Tb（aspirin）3phen可增加MCM-41的骨架有序性，充当“二次模板剂”的作用。IR谱图中，Tb（aspirin）3phen-MCM-41组装体在波数1384cm^-1处明显保留了Tb-N键的振动吸收。405nm发射峰强度，L和544nm发射峰强度，ILn的比值I，与McM-41不同的表面环境有关，且McM-41的不同表面环境对配体phen三重态和单重态能级的影响顺序为：MCM-41B外表面〉MCM-41A外表面〉McM-41A内表面。     

稀土配合物/MCM-41分子筛杂化发光材料的制备

以十六烷基三甲基溴化铵(CTAB)为模板剂,正硅酸乙酯(TEOS)为硅源,采用水热法制备了晶粒平均尺寸8nm纳米MCM-41;以稀土铕为中心,水杨酸为第一配体,邻菲罗啉为第二配体,合成了稀土配合物Eu(Sal)_3Phen。用浸渍法将Eu(Sal)_3Phen组装到MCM-41分子筛中成为Eu(Sal)_3Phen/MCM-41杂化发光材料。红外分析表明稀土配合物成功组装到MCM-41分子筛的孔道中,X射线衍射表明MCM-41的结晶性好,组装后MCM-41的晶面衍射峰强度稍减弱,扫描电镜表明产品为六方均匀有序结构。在365nm激发波长,发射波长为621nm,为典型红光,是(5D0-7F2)发射的结果,Eu3+掺量9%时发光强度达最大,稀土配合物组装后性能更加稳定,在浓度12%未发生浓度猝灭。     

MCM-41介孔分子筛和纳米TiO2/MCM-41的合成与结构表征

以工业水玻璃为硅源,表面活性剂十六烷基三甲基溴化铵为结构模板剂,利用室温晶化法合成出MCM-41介孔分子筛,并以钛酸丁酯为前驱体,通过溶胶凝胶法及液相沉积法对介孔分子筛MCM-41进行纳米TiO2的组装。运用XRD、FT-IR、N2吸附-脱附等表征手段对其结构特征和氧化钛分散状态进行了研究,结果表明：TiO2与MCM-41端基硅氧键反应形成Ti-O-Si键;纳米TiO2不仅进入孔道,较均匀地修饰了介孔分子筛MCM-41的孔壁,而且使介孔分子筛MCM-41仍保持有序的孔道结构。     

有序双组分氧化物CoO-NiO/MCM-41催化剂的合成与表征

在碱性条件下用组装的方法得到了高负载量,均匀分布的CoO-NiO负载型MCM-41介孔材料,并采用XRD、BET、HREM等测试手段对样品进行了分析,结果表明,CoO,NiO双组分氧化物已成功地组装进入了MCM-41的有序孔道,在CoO,NiO组装过程中,CoO,NiO含量分别为7.53wt％和5.94wt％时,介孔材料的有序结构没有遭到破坏。     

聚焦超声刺激交联聚乙烯醇-介孔二氧化硅复合材料形状记忆和药物释放

以介孔二氧化硅MCM-41作为药物载体吸附布洛芬,通过与聚乙烯醇水溶液混合、交联制备了交联聚乙烯醇形状记忆复合材料。采用高强度聚焦超声作为刺激手段,研究了交联聚乙烯醇复合材料的形状记忆性能和药物释放性能。结果表明,在高强度聚焦超声作用下,交联聚乙烯醇形状记忆复合材料具有良好的形状记忆性能,形状回复率随着超声时间的延长逐渐增大直至达到平衡状态,形状回复率可达~90%,且最终回复率随着SiO2/ibuprofen载入量的增大明显下降;同时,聚焦超声实现了布洛芬的可控周期性释放过程,调节聚焦超声时间和功率可以调节布洛芬的释放量;另外,SiO2/ibuprofen的加入提高了聚乙烯醇复合材料的热稳定性。     

MCM-41与8-羟基喹啉铝复合发光材料的制备与性能研究

以十六烷基三甲基溴化铵（CTAB）为模板剂，正硅酸乙酯（TEOS）为硅源，在有机弱碱和室温条件下制备出高度有序的介孔材料MCM-41。以氯仿、乙醇为混合溶剂，将有机发光小分子8-羟基喹啉铝（Alq3）组装进介孔MCM-41中，得到有机-无机复合发光材料。采用XRD、IR、紫外-可见漫反射、N2吸附-脱附、激发发射等测试方法对产物的结构和性能进行了分析，结果表明，组装体保持了有序的介孔结构，并且主客体之间存在较强的相互作用。     

杂多酸固载催化剂的合成及窄分子量纤维素制备的研究

通过水热合成法制备MCM-41型介孔分子筛,采用浸渍法负载磷钨酸于MCM-41介孔分子筛中,煅烧得到新型HPW/MCM-41固载催化剂。利用傅里叶红外光谱(FT-IR)、X射线衍射(XRD)、热重分析(TG)和扫描电镜(SEM)对固载催化剂进行表征;考察催化剂对棉纤维催化降解反应的性能。结果表明,新型HPW/MCM-41固载催化剂即持有了磷钨酸的Keggin结构,同时又保持了分子筛的完整介孔结构,具有催化、筛分双重性能。棉纤维催化降解反应数据显示,磷钨酸负载量、反应温度、催化剂用量、液固比及停留时间均影响HPW/MCM-41降解纤维素的性能。在单因素实验最佳反应条件下,棉纤维素降解产物的分子量分布较为均匀,降解产物的产率较优。     

The investigation of MCM-48-type and MCM-41-type mesoporous silica as oral solid dispersion carriers for water insoluble cilostazol

Objective: To explore the suitable application of MCM-41 (Mobil Composition of Matter number forty-one)-type and MCM-48-type mesoporous silica in the oral water insoluble drug delivery system.

Methods: Cilostazol (CLT) as a model drug was loaded into synthesized MCM-48 (Mobil Composition of Matter number forty-eight) and commercial MCM-41 by three common methods. The obtained MCM-41, MCM-48 and CLT-loaded samples were characterized by means of nitrogen adsorption, thermogravimetric analysis, ultraviolet-visible spectrophotometry, scanning electron microscopy, transmission electron microscopy, differential scanning calorimetry and powder X-ray diffractometer.

Results: It was found that solvent evaporation method was preferred according to the drug loading efficiency and the maximum percent cumulative drug dissolution. MCM-48 with 3D cubic pore structure and MCM-41 with 2D long tubular structure are nearly spherical particles in 300–500?nm. Nevertheless, the silica carriers with similar large specific surface areas and concentrating pore size distributions (978.66?m²/g, 3.8?nm for MCM-41 and 1108.04?m²/g, 3.6?nm for MCM-48) exhibited different adsorption behaviors for CLT. The maximum percent cumulative drug release of the two CLT/silica solid dispersion (CLT-MCM-48 and CLT-MCM-41) was 63.41% and 85.78% within 60?min, respectively; while in the subsequent 12?h release experiment, almost 100% cumulative drug release were both obtained. In the pharmacokinetics aspect, the maximum plasma concentrations of CLT-MCM-48 reached 3.63?mg/L by 0.92?h. The AUC_0–∞ values of the CLT-MCM-41 and CLT-MCM-48 were 1.14-fold and 1.73-fold, respectively, compared with the commercial preparation.

Conclusion: Our findings suggest that MCM-41-type and MCM-48-type mesoporous silica have great promise as solid dispersion carriers for sustained and immediate release separately.     

Preparation and luminescence properties of the mesoporous MCM-41s intercalated with rare earth complex

Rare earth complex Eu(DBM)₃phen (DBM: dibenzoylmethane, phen: 1,10-phenanthroline) has been incorporated into unmodified MCM-41 and modified MCM-41s by aminopropyltriethoxysilane (APTES) or N-[(3-triethoxysilyl)propyl]ethylenediamine (TEPED). Thus, the assemblies of unmodified or modified MCM-41s with rare earth (RE) complex have been obtained. XRD spectra, NMR spectra, diffuse reflectance spectra, and the luminescence spectra were used to characterize the pure RE complex and the corresponding assemblies. The assemblies have better luminescence properties under UV irradiation, and their fluorescence lifetimes on the excited state are longer than that of the corresponding pure complex. The possible mechanisms are also discussed in the context.     

金属Pt团簇在氧化钛修饰MCM-41中的组装

采用光沉积的合成方法将纳米金属Ｐｔ组装于氧化钛修饰ＭＣＭ－４１孔道中,并对合成的样品进行了ＸＲＤ、ＸＰＳ、ＵＶ－vis、Ｎ₂吸附－脱附等结构表征．光电子能谱表明组装的Ｐｔ呈金属状态;Ｎ_２吸附－脱附数据表明组装于孔道中的Ｐｔ虽然使ＭＣＭ－４１的ＢＥＴ比表面和孔容下降,但是由于Ｐｔ的组装量较小,使其对孔径分布的影响较小．由于Ｐｔ的引入,使其紫外－可见光漫反射吸收光谱与氧化钛修饰的ＭＣＭ－４１不同．     

Functionalization of mesoporous MCM-41 for the delivery of curcumin as an anti-inflammatory therapy

In this study, mesoporous silica nanoparticles (MSNs) composed of MCM-41 were synthesized and modified with amine groups (i.e., NH₂) to form NH_2/MCM-41, which was loaded with curcumin (CUR) to form CUR@NH₂/MCM-41 to create an efficient carriers in drug delivery systems (DDSs). The three samples (i.e., pure MCM-41, NH₂/MCM-41, and CUR@NH₂/MCM-41) were characterized using X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) surface area, Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), transition electron microscopy (TEM), and a thermogravimetric analyzer (TGA). The study investigated the effect of the carrier dose, CUR concentration, pH, and contact time on the drug loading efficiency (DLE%) by adsorption. The best DLE% for MCM-41 and NH₂/MCM-41 was found to be 15.78 and 80%, respectively. This data demonstrated that the Langmuir isotherm had a greater correlation coefficient (R²) of 0.9840 for MCM-41 and 0.9666 for NH₂/MCM-41 than the Freundlich and Temkin isotherm models. A pseudo-second-order kinetic model seems to fit well with R² = 0.9741 for MCM-41 and R² = 0.9977 for NH₂/MCM-41. A phosphate buffer solution (PBS) with a pH of 7.4 was utilized to study CUR release behavior. As a result, the full release after 72 h was found to have a maximum of 74.1% and 29.95% for pure MCM-41 and NH₂/MCM-41, respectively. The first-order, Weibull, Hixson-Crowell, Korsmeyer-Peppas, and Higuchi kinetic release models were applied to releasing CUR from CUR@MCM-41 and CUR@NH₂/MCM-41. The Weibull kinetic model fit well, with R² = 0.944 and 0.96912 for pure MCM-41 and NH₂/MCM-41, respectively.     

Synthesis of MCM-41 from coal fly ash by a green approach: influence of synthesis pH

The present study reports a green synthesis method for preparing pure (free of fly ash) and ordered MCM-41 materials from coal fly ash at room temperature (25 degrees C) during 24 h of reaction. It was shown that the impurities in the coal fly ash were not detrimental to the formation of MCM-41 at the tested conditions. The influence of initial synthesis pH on material properties of calcined MCM-41 samples was investigated by various techniques such as XRF, XPS, XRD, FTIR, DR-UV-vis, solid state NMR, N2 physisorption, TG-DTA, SEM and TEM. The experimental results showed that the amount of trace elements such as Al, Na, Ti and Fe incorporated into the sample increased with synthesis pH value. More aluminum species were incorporated with tetrahedral coordination in the framework under a high pH value. The particle size of the sample decreased with the synthesis pH value. Samples synthesized at high pH values had a larger pore size and were more hydrothermally stable than those at low pH values. From thermal analysis, it was observed that the synthesized MCM-41 samples showed a high thermal stability. These properties made the synthesized MCM-41 suitable for further processing into more useful materials in a wide range of applications.     

Synthesis and characterization of mesoporous Si-MCM-41 materials and their application as solid acid catalysts in some esterification reactions

Mesoporous MCM-41 has been synthesized by sol–gel method at room temperature possessing good thermal stability, high surface area as well as retention of surface area at high temperature. The MCM-41 neutral framework has been modified and put to practical use by incorporating Al³⁺ in the siliceous MCM-41 framework and supporting 12-TPA (12-tungstophosphoric acid) onto MCM-41 by process of anchoring and calcination to induce Brønsted acidity in MCM-41 to yield Al-MCM-41 and 12TPA-MCM-41, respectively. The synthesized materials have been characterized for elemental analysis by ICP-AES, XRD, SEM, TEM, EDX, FT–IR and TGA. Surface area has been determined by BET method and pore size and pore size distribution determined by BJH method. Surface acidity has been evaluated by NH₃-TPD method. The potential use of Al-MCM-41 and 12TPA-MCM-41 as solid acid catalysts has been explored and compared by studying esterification as a model reaction wherein monoesters such as ethyl acetate (EA), propyl acetate (PA), butyl acetate (BA) and benzyl acetate (BzA) have been synthesized, optimizing several parameters such as catalyst amount, reaction time, reaction temperature and mole ratio of reagents.     

Preparation of highly dispersed tungsten oxide on MCM-41 via atomic layer deposition and its application to butanol dehydration

Highly dispersed tungsten oxide on MCM-41 was synthesized using a novel atomic layer deposition (ALD) method. BET, XRD, XPS, NH3-TPD, and pyridine-IR were used to study the physicochemical properties of the supported tungsten oxides. In this study, the maximum loading of tungsten oxide on MCM-41 that could be prepared using the modified ALD method was 27.0 wt%. It was confirmed that the textural properties of the mesoporous silica were maintained after tungsten oxide loading. The NH3-TPD and Py-IR results indicated that weak acid sites, mainly Lewis acid sites, were produced over the WO3/MCM-41 samples. Moreover, 2-butanol dehydration was performed to demonstrate the potential advantages of the WO3/MCM-41 catalysts. The WO3/MCM-41 catalyst with 27.0 wt% tungsten oxide loading showed the highest activity in the dehydration of 2-butanol, which was attributed to the highest overall number of acid sites among the WO3/MCM-41 catalysts. The highly dispersed tungsten oxide on MCM-41 prepared via ALD can be an effective catalyst for producing butenes through 2-butanol dehydration.     

Glass–ceramic scaffolds containing silica mesophases for bone grafting and drug delivery

Glass–ceramic macroporous scaffolds were prepared using glass powders and polyethylene (PE) particles of two different sizes. The starting glass, named as Fa-GC, belongs to the system SiO₂–P₂O₅–CaO–MgO–Na₂O–K₂O–CaF₂ and was synthesized by a traditional melting-quenching route. The glass was ground and sieved to obtain powders of specific size which were mixed with PE particles and then uniaxially pressed in order to obtain crack-free green samples. The compact of powders underwent a thermal treatment to remove the organic phase and to sinter the Fa-GC powders. Fa-GC scaffolds were characterized by means of X-Ray Diffraction, morphological observations, density measurements, image analysis, mechanical tests and in vitro tests. Composite systems were then prepared combining the drug uptake-delivery properties of MCM-41 silica micro/nanospheres with the Fa-GC scaffold. The system was prepared by soaking the scaffold into the MCM-41 synthesis batch. The composite scaffolds were characterized by means of X-Ray Diffraction, morphological observations, mechanical tests and in vitro tests. Ibuprofen was used as model drug for the uptake and delivery analysis of the composite system. In comparison with the MCM-41-free scaffold, both the adsorption capacity and the drug delivery behaviour were deeply affected by the presence of MCM-41 spheres inside the scaffold.