改性SBA-15介孔孔道内甲基丙烯酸甲酯的反向原子转移自由基聚合的溶液聚合

分别使用硅烷偶联剂KH-151、KH-560、KH-570对介孔材料SBA-15进行改性,以改性前后的介孔材料作为"微反应器",在其内部进行了甲基丙烯酸甲酯(MMA)的反向原子转移自由基聚合(RATRP)。通过X射线衍射、氮气吸附-脱附测试、热重分析、差示扫描量热、凝胶渗透色谱、傅里叶变换红外光谱等手段对所得产物进行了测试表征。结果表明,MMA在改性前后的SBA-15内部聚合成功;聚合后的复合材料仍然保持其SBA-15的母体结构,但比表面积、孔径、孔体积均有所下降;孔道内所得的PMMA较常规RATRP聚合所得的PMMA相对分子质量有所增加,相对分子质量分布变宽,初始热分解温度升高,玻璃化转变温度升高;改性后介孔材料对反应液有更好的吸附能力且对孔道内的MMA的RATRP溶液聚合有更强的孔道限制作用。     

不同孔径SBA-15内甲基丙烯酸甲酯的反向原子转移自由基溶液聚合

用不同孔径的介孔材料SBA-15作为"微反应器",在其孔道内进行甲基丙烯酸甲酯(MMA)的反向原子转移自由基聚合反应(RATRP)。分别通过氮气吸附/脱附、X射线粉末衍射和透射电镜表征了介孔材料和产物的孔参数、晶体结构和形态;采用热重分析、差示扫描量热、凝胶渗透色谱、核磁共振等手段对所得产物在介孔材料中的含量、玻璃化转变温度(T_g)、相对分子质量和立体规整度进行了测试表征。结果表明,MMA在不同孔径介孔材料SBA-15孔道内成功进行了RATRP;聚合后的复合材料保持了介孔材料SBA-15的结构,比表面积、孔体积均有所下降。随着SBA-15的孔径增加,内部所得聚合物的数均相对分子质量最大增加1.25倍,T_g最大升高了18.4℃,间规立构比例逐渐上升。     

引发剂用量对SBA-15孔道内甲基丙烯酸甲酯溶液聚合的影响

利用介孔分子筛SBA-15的介孔孔道结构,通过调节引发剂过氧化苯甲酰的用量,在其内部进行了甲基丙烯酸甲酯(MMA)的原位溶液聚合反应,利用X射线衍射、N2吸附-脱附、傅里叶变换红外光谱、凝胶渗透色谱、热重、差示扫描量热等测试手段对所得复合材料及孔道内的聚合物进行研究。结果表明,聚合后,复合材料的比表面积、孔径、孔容降低,但仍保持介孔结构;孔道内聚合物相对分子质量是常规溶液聚合的几十倍,随着引发剂用量的增加,孔道内部聚合的PMMA含量增加,相对分子质量下降,相对分子质量分布变宽,热稳定性提高,玻璃化转变温度降低。     

SBA-15/PDCPD复合材料的阻燃性能

分别采用介孔分子筛SBA-15原位聚合及SBA-15负载催化剂六氯化钨原位聚合的方法制备了SBA-15/聚双环戊二烯(PDCPD)复合材料,研究了SBA-15/PDCPD复合材料的阻燃性能.研究结果表明:采用原位聚合方法制备的复合材料,SBA-15孔道中的双环戊二烯(DCPD)单体难以发生聚合反应生成PDCPD分子链,...     

镧(Ⅲ)对SBA-15分子筛改性研究

借助水热法,利用三嵌段共聚物聚(1,2-亚乙基二醇)-嵌段-聚(丙二醇)-嵌段-聚(1,2-亚乙基二醇)为模板剂,正硅酸四乙酯为硅源,强酸性条件下制备了分子筛SBA-15.分别以水及水+乙醇为介质采用LaCl3溶液与煅烧的主体材料SBA-15分子筛固-液相交换法,制备了La-(SBA-15)复合材料.利用化学分析、粉末XRD、N2吸附技术、IR评价了制备方法的有效性及对SBA-15分子筛孔结构的影响.结果表明,镧已并入SBA-15分子筛中,SBA-15内表面上的硅羟基团是镧进入的主要位置,部分客体在分子筛孔道内.制得的材料La-(SBA-15)保持高度有序的介孔二维六角结构,不改变载体SBA-15的介孔孔道结构.此外,考察了La-(SBA-15)产物的发光现象.     

介孔SBA-15对不饱和聚酯树脂及其复合材料性能的影响EI北大核心CSCD

采用自制介孔SBA-15,利用原位聚合法制备SBA-15/不饱和聚酯(UP)原位树脂。通过模压制得SBA-15/UP复合材料。利用冲击、氮气吸附-脱附、蠕变和应力松弛测试、摩擦测试、扫面电镜等测试手段对SBA-15/UP原位树脂及其复合材料的性能进行表征,研究不同SBA-15含量对SBA-15/UP复合材料性能的影响。结果表明,聚合后,SBA-15的孔径减小。SBA-15的加入能有效改善SBA-15/UP复合材料的摩擦性能和尺寸稳定性,蠕变和应力松弛性能明显得到改善。当SBA-15加入量为2%时,体积磨损率降低了19.58%,冲击强度提高了29.83%。     

聚苯胺/MCM-41介孔分子筛导电复合材料的制备及其表征

利用MCM-41介孔分子筛单分散孔道特性作为"纳米反应器",在其孔道内合成聚苯胺.讨论了HCl浓度、(NH4)2SO8浓度和聚合温度对复合材料导电性的影响,得到最佳的聚合条件:HCl:1.5mol/L,(NH4)2SO8:1.0mol/L,聚合温度:15℃,此时的电导率为0.61s/cm.在最佳合成条件下,对聚苯胺/MCM-41介孔分子筛导电复合材料进行SEM、红外光谱分析.     

粉煤灰合成介孔分子筛SBA-15对稀土元素的吸附

以粉煤灰为原料、EO_(20)PO_(70)EO_(20)(P123)为模板剂,采用碱溶-水热法制备出高度有序的介孔分子筛SBA-15;以3-氨丙基三乙氧基硅烷(APTES)为修饰剂对SBA-15进行表面氨基化。再用膦酰基乙酸(PAA)、二乙烯三胺五乙酸二酐(DTPADA)对其进一步功能化,合成材料PAA-SBA-15和DTPADA-SBA-15。通过小角XRD衍射、全反射红外、和氮气吸附对材料进行了分析和表征,并研究了材料对稀土元素Yb、Ho的吸附性能。结果表明,经过不同官能团修饰的材料依然具有良好的介孔结构;此外吸附结果表明,在pH值为6时,PAA-SBA-15对Ho、Yb的吸附效率分别为89.8%,94.4%;在pH值为2时,DTPADA-SBA-15对Ho、Yb的吸附效率为92.6%,89.0%。     

介孔分子筛/线性酚醛树脂杂化材料的制备及表征

利用水热法合成介孔分子筛(SBA-15),选择KH560对其表面进行修饰后采用原位聚合的方法制备了介孔分子筛/线性酚醛树脂(SBA-15/PF)有机无机杂化材料。通过傅立叶红外光谱(FT-IR)、X射线衍射(XRD)、N2吸附和热失重分析(TGA)等表征手段对杂化材料的制备过程进行跟踪研究。结果表明,KH-560已嫁接到SBA-15的内外表面,线性酚醛树脂分布于介孔分子筛孔道内外,并与SBA-15存在键接作用,形成有机无机互穿网络结构;表面修饰过程对SBA-15有序结构影响较小,而原位聚合会破坏介孔分子筛部分有序结构。     

纳米浇注法制备有序介孔WC/C复合材料及电催化性能

以介孔SiO2为硬模板,通过纳米浇注法在模板孔道中引入不同质量配比的碳源和钨源前驱物,经过高温碳化还原反应,刻蚀除去模板后得到了介观结构有序的SBA-15和KIT-6介孔碳化钨/炭(WC/C)复合材料。采用XRD、TEM、EDX、TGA、CV和N2吸附-脱附等测试手段,对所得复合材料进行了物化性质分析和结构表征。结果表明,该介孔WC/C复合材料具有有序的介观结构(p6mm,Ia3d)、高的比表面积(约500m2/g)和较大的孔径(约4nm)。CV测试表明,三维贯通的有序TC/C-KIT-6为载体负载Pt催化剂,对甲醇的催化氧化具有更优异的作用。     

Novel magnetite-silica nanocomposite (Fe3O4-SBA-15) particles for DNA binding and gene delivery aided by a magnet array

Novel magnetite-silica nanocomposite particles were prepared using SBA-15 nanoporous silica as template. Magnetite nanoparticles were impregnated into the nanopore array of the silica template through thermal decomposition of iron(III) acetylacetonate, Fe(AcAc)3 at 200 degrees C. These composite particles were characterized using TEM, XRD and SQUID magnetometry. The TEM images showed that the size of composite particles was around 500 nm and the particles retained the nanoporous array of SBA-15. The formation of magnetite nanoparticles was confirmed by the powder XRD study. These composite particles also exhibited ferrimagnetic properties. By coating with short chain polyethyleneimine (PEI), these particles are capable of binding DNA molecules for gene delivery and transfection. With an external magnetic field, the transfection efficiency was shown to have an increase of around 15%. The results indicated that these composite nanoparticles may be further developed as a new tool for nanomagnetic gene transfection.     

SBA-15介孔分子筛吸附电镀废水中Cu2＋的最佳条件和效果

为了开发新型高效廉价的吸咐材料,利用常压微波辐射法在酸性条件下以三嵌段共聚物（P123）为模板剂,制备了高度有序的SBA．15型介孔分子筛。研究了静态条件下SBA-15对电镀废水中Cu2＋的吸附,探讨了SBA-15用量、废水pH值、吸附时间、吸附温度对去除Cun效果的影响。结果表明：废水pH值为5．0,Cu2＋在0—1...     

Removal of patulin from aqueous solutions by propylthiol functionalized SBA-15

Propylthiol functionalized SBA-15 silica was investigated to detoxify aqueous solutions contaminated with the regulated mycotoxin patulin. Micelle templated silicas with a specific pore size were synthetically modified to possess propylthiol groups, a functional group known to form Michael reaction products with the conjugated double bond system of patulin. BET surface area analysis indicated the propylthiol functionalized SBA-15 possesses channels with the pore size of 5.4 nm and a surface area of 345 m(2)g(-1). Elemental analysis indicates the silicon/sulfur ratio to be 10:1, inferring one propylthiol substituent for every ten silica residues. The propylthiol modified SBA-15 was effective at significantly reducing high levels of patulin from aqueous solutions (pH 7.0) in batch sorption assays at room temperature. The material was less effective at lower pH; however heating low pH solutions and apple juice to 60 °C in the presence of propylthiol functionalized SBA-15 significantly reduced the levels of patulin in contaminated samples. Composite molecular models developed by semi-empirical PM3 and empirical force field methods support patulin permeation through the mesoporous channels of propylthiol functionalized SBA-15. Density functional study at the B3LYP/6-31G(d,p) level predicts the proposed patulin adducts formed by reaction with the thiol residues exhibit less electrophilic properties than patulin. It is demonstrated the use of propylthiol functionalized SBA-15 is a viable approach to reduce patulin levels in aqueous solutions, including contaminated apple juice.     

Magnetic properties of SBA-15 mesoporous nanocomposites with CoFe2O4 nanoparticles

A novel mesoporous nanocomposite based on SBA-15 with CoFe₂O₄ and Fe₂O₃ magnetic nanoparticles was prepared via the hydrothermal treatment and impregnation method. We showed that Fe₂O₃ nanoparticles were anchored in the frame and CoFe₂O₄ nanoparticles were confined in the mesopores of SBA-15 in the prepared nanocomposite. Our results indicated that the magnetic properties could be adjusted by the addition of CoFe₂O₄ and Fe₂O₃ magnetic nanoparticles. The presence of couple exchange interaction was confirmed with Kelly-Hankel (δM) curves, which enhanced the magnetic properties of the CoFe₂O₄/Fe₂O₃-SBA-15 mesoporous nanocomposite.     

介孔分子筛/聚双环戊二烯复合材料的制备

将负载催化剂的SBA-15型介孔分子筛(方法1)、偶联剂表面改性的SBA-15 (方法2)、偶联剂表面改性后负载催化剂的SBA-15 (方法3), 采用原位聚合法分别制备了SBA-15/聚双环戊二烯(PDCPD)复合材料。研究了不同制备方法对SBA-15/PDCPD力学性能的影响。结果表明, 对于方法2, 虽然偶联剂改性SBA-15可提高与PDCPD界面作用力, 但由于分子筛孔道中的双环戊二烯(DCPD)单体难以发生聚合反应, 导致复合材料的力学性能较PDCPD没有明显改善。采用方法1及方法3可使PDCPD分子链在SBA-15孔道中生成, 改善了PDCPD基体与SBA-15的界面作用力, 使复合材料的力学性能明显改善。采用方法1, SBA-15/PDCPD质量比为2∶100时, 复合材料拉伸强度较PDCPD提高了24.5%, 弯曲强度提高了24%。采用方法3制备的复合材料中偶联剂分子占据了SBA-15孔道空间, 导致孔道中生成聚合物分子链数量较方法1少, 使其力学性能提高幅度低于方法1, 但优于方法2。     

Amine and thiol functionalization of SBA-15 nanoparticles for highly efficient adsorption of sulforaphane

This study presents a novel material for highly efficient adsorption of sulforaphane based on SBA-15. The SBA-15 nanoparticles were synthesized using natural silica by hydrothermal method and functionalized with thiol and amine groups by the post-synthesis grafting procedure. All adsorbents were characterized by various techniques including BET, LAXRD, FT-IR, FE-SEM, and CHNS. The batch adsorption experiments revealed that the adsorption efficiency of SBA-15 for sulforaphane can be mainly influenced by the introduction of functional groups and the best adsorption performance was observed for amine-functionalized SBA-15 (SBA-15-NH₂) compared to pure SBA-15 and thiol-functionalized SBA-15 (SBA-15-SH) with the highest adsorption efficiency of about 97%. Preliminary adsorption studies of sulforaphane onto SBA-15-NH₂ were performed in aqueous solutions with different pH values and various organic solvents. Also, the effects of adsorbent dosage, contact time, and initial sulforaphane concentration on sulforaphane adsorption using SBA-15-NH₂ were studied. Langmuir and Redlich-Peterson isotherm models were the best-fitting models for the experimental data, followed by Temkin, Freundlich, and Dubinin-Radushkevich models. The adsorption process could be well described by the pseudo-first-order kinetic model based on kinetic parameters, correlation coefficient, and error functions. Meanwhile, the intra-particle diffusion model showed a multi-linear plot with three steps demonstrating slow diffusion into mesopores as a rate-limiting step.     

巯基改性SBA-15的制备及其对Cr6+的吸附

环境中存在的重金属铬对人体健康有严重的危害, 本研究采用水热共缩聚法制备了一种对Cr ⁶⁺有较高吸附能力的介孔材料SBA-15-SH。经红外光谱证实, 通过使用改性硅源3-巯丙基三甲氧基硅烷, 对SBA-15成功实现了巯基改性。经扫描电子显微镜(SEM)和透射电子显微镜(TEM)观察, 所制备的材料呈棒状, 具有均匀的孔道结构, 孔径约为7 nm。将制备材料用于重金属Cr ⁶⁺的吸附, 研究了吸附时间、环境温度、Cr ⁶⁺溶液pH和初始浓度以及吸附剂用量对吸附剂吸附性能的影响。研究表明: 该材料吸附Cr ⁶⁺的平衡吸附时间约10 min, 吸附过程符合Langmuir方程与伪二级动力学模型。当Cr ⁶⁺溶液pH为4.0、吸附温度在25~45 ℃时, 介孔材料SBA-15-SH对Cr ⁶⁺吸附量最大, 达到6.85 mg/g。将本方法用于自来水和工业废水中Cr ⁶⁺的吸附, 回收率介于95%~105%之间。     

Functionalization of SBA-15 by dithiooxamide towards removal of Co (II) ions from real samples: Isotherm,thermodynamic and kinetic studies

In this study, mesoporous SBA-15 was functionalized by dithiooxamide ligand through sodium dodecyl sulfate as intermediate. The obtained nanocomposite was considered as a strong adsorbent towards selective removal of the cobalt (II) ions from the industrial wastewater samples. Transmission Electron Microscopy (TEM) analysis, Brunauer-Emmett-Teller (BET) analysis, elemental CHNS (carbon, hydrogen, nitrogen, and sulfur) analysis, and thermo-gravimetric analysis (TGA) were used for characterization, particle size determination, confirming the presence of the used ligand, and measuring the nanocomposite stability, respectively. Effective parameters on the removal of the cobalt (II) ions such as pH, adsorbent dosage, concentration, and contact time have been evaluated. Results showed that the Freundlich isotherm has a bit better correlation coefficient compared to Langmuir isotherm (0.96 versus 0.94, respectively). The maximum amount of Co (II) ions adsorption on 1 g of nanocomposite (q_m) is calculated to be 2500 mg/g that points to the excellent adsorption. Kinetic analyses were conducted using pseudo-first and second-order models and the regression results showed that the pseudo-second-order model is more accurate for the study of the cobalt adsorption due to the higher correlation coefficient (0.99 versus 0.83) compared to the pseudo-first-order model. The result of the present study points that the suggested nanocomposite can be positively used in treating industrial effluents containing cobalt ions.