Controlled chemical modification of the internal surface of photonic crystal fibers for application as biosensitive elements

Photonic crystal fibers (PCF) are one of the most promising materials for creation of constructive elements for bio-, drug and contaminant sensing based on unique optical properties of the PCF as effective nanosized optical signal collectors. In order to provide efficient and controllable binding of biomolecules, the internal surface of glass hollow core photonic crystal fibers (HC-PCF) has been chemically modified with silanol groups and functionalized with (3-aminopropyl) triethoxysilane (APTES). The shift of local maxima in the HC-PCF transmission spectrum has been selected as a signal for estimating the amount of silanol groups on the HC-PCF inner surface. The relationship between amount of silanol groups on the HC-PCF inner surface and efficiency of following APTES functionalization has been evaluated. Covalent binding of horseradish peroxidase (chosen as a model protein) on functionalized PCF inner surface has been performed successively, thus verifying the possibility of creating a biosensitive element.     

Incorporation of a tungsten Fischer-type metal carbene covalently bound to functionalized SBA-15

A metal Fischer carbene [(CO)₅WC(φ)OCH₂CH₃] was covalently linked for the first time to the silanol groups of the mesoporous channels of SBA15 by following two different synthetic anchoring routes. The first one goes through the reaction of the SBA15 mesoporous silica walls functionalized by aminopropyltriethoxysilane (APTES) with a tungsten carbene Wφ, while in the second approach a precursor synthesized by reacting APTES with the carbene Wφ is then anchored via a direct bond to the silanol groups in the interior pore channels of SBA-15.

This tethering is helpful to prevent the decomposition of the metallic complex. XRD, N₂ adsorption–desorption, and TEM analysis provide strong evidence that the mesoporous support structure retains its long-range ordering after the grafting process, despite a significant reduction of its specific surface area, pore-volume and pore-size. The chemical bonding of the tungsten carbene to the silanol groups of SBA-15 materials was studied with solid-state NMR spectroscopy. Both ¹³C MAS NMR and ²⁹Si CP MAS NMR spectra confirm the covalent linking of the carbene to the silica-pore system.     

低温溶胶型APTES改性聚氨酯在羊毛织物上的应用

 为减少羊毛防毡缩整理时溶胶-凝胶法高温焙烘造成的织物损伤和泛黄倾向,合成出一种溶胶型APTES改性的聚氨酯低温防毡缩整理剂。通过异佛尔酮二异氰酸酯（IPDI）与嵌段聚醚二元醇（PPD）反应,合成出端基含有NCO基团的预聚体,再经3-氨丙基三乙氧基硅烷（APTES）封端后得到的PPD-[Si(OEt)3]2前驱体水解,即得新型整理剂产品。采用FTIR和TGA对样品凝胶化后形成的杂化结构和热性能进行表征, 比较不同焙烘温度条件下（120、140、160℃）样品的防毡缩性能。结果表明：低温条件下（120 ℃,3 min）处理的羊毛样品可获得良好的防毡缩效果,面积毡缩率在3%之内。     

Enhanced methanol oxidation on PtNi nanoparticles supported on silane-modified reduced graphene oxide

Developing low cost, highly efficient, and long-term stability electrocatalysts are critical for direct oxidation methanol fuel cell. Despite huge efforts, designing low-cost electrocatalysts with high activity and long-term durability remains a significant technical challenge. Here, we prepared a new kind of platinum-nickel catalyst supported on silane-modified graphene oxide (NH₂-rGO) by a two-step method at room temperature. Powder X-ray diffraction, UV–vis spectroscopy, Raman, FTIR spectroscopy and X-ray photoelectron spectroscopy results confirm that GO was successfully modified with 3-aminopropyltriethoxysilane (APTES), which helps to uniformly disperse PtNi nanoparticles. Cyclic voltammetry, chronoamperometry, CO-stripping and rotating disk electrode (RDE) results imply that PtNi/NH₂-rGO catalyst has significantly higher catalytic activity, enhance the CO toxicity resistance, higher stability and much faster kinetics of methanol oxidation than commercial Pt/C under alkaline conditions.     

多壁碳纳米管在不同表面功能基团自组装膜上的沉积

制备了表面功能基团为氨基和甲基的自组装膜,将不同表面功能基团自组装膜浸入多壁碳纳米管分散液中沉积,实验观察到,表面为氨基的APTES自组装膜对分散液中的碳纳米管有静电吸附作用而均匀吸附一层碳纳米管,表面为甲基的OTS自组装膜对分散液碳纳米管有排斥作用力而没有吸附碳纳米管,这一实验对利用单根碳纳米管构造纳米电子器件与纳米机械具有重要意义。     

Silicate-based polymer-nanocomposite membranes for polymer electrolyte membrane fuel cells

Proton-exchange membrane fuel cells have emerged as a promising emission free technology to fulfill the existing power requirements of the 21st century. Nafion^® is the most widely accepted and commercialized membrane to date and possesses excellent electrochemical properties below 80 °C, under highly humidified conditions. However, a decrease in the proton conductivity of Nafion^® above 80 °C and lower humidity along with high membrane cost has prompted the development of new membranes and techniques. Addition of inorganic fillers, especially silicate-based nanomaterials, to the polymer membrane was utilized to partially overcome the aforementioned limitations. This is because of the lower cost, easy availability, high hydrophilicity and higher thermal stability of the inorganic silicates. Addition of silicates to the polymer membrane has also improved the mechanical, thermal and barrier properties, along with water uptake of the composite membranes, resulting in superior performance at higher temperature compared to that of the virgin membrane. However, the degrees of dispersion and interaction between the organic polymer and inorganic silicates play vital roles in improving the key properties of the membranes. Hence, different techniques and solvent media were used to improve the degrees of nanofiller dispersion and the physico-chemical properties of the membranes. This review focuses mainly on the techniques of silicate-based nanocomposite fabrication and the resulting impact on the membrane properties.     

Preparation and Characterization of Aminopropylsilatrane Endcapped Polyimide Films

γ-Aminopropylsilatrane (APS)/γ-aminopropyltriethoxysilane (APTES) end capped polyimide films were prepared by thermal imidization method. Polyamic acid (PAA) was prepared by the reaction of 4,4′-oxydianiline (ODA) with 4,4′-oxydipthalicdianhydride (ODPA) using dimethylacetamide (DMAc) as solvent. The end group of prepared PAA was capped by different percentage of APS/APTES. The polyimide films were characterized by different advanced instrumental techniques for chemical/physical properties. APS end capped PI films show better thermal and mechanical properties and air permeability than APTES end capped polyimide films.     

APTES改性微晶纤维素对淀粉复合薄膜性能影响

目的 探究3-氨丙基三乙氧基硅烷（3-AminopropylTriethoxysilane,APTES）改性微晶纤维素（MicrocrystallineCellulose,MCC）对淀粉基复合薄膜的影响,以期改性得到的硅烷化微晶纤维素（Silanized Microcrystalline Cellulose, MMCC）能够提高淀粉基薄膜的性能。方法 在90℃下糊化淀粉后加入MCC或MMCC,以溶液浇铸法制备淀粉基复合薄膜,采用扫描电子显微镜（SEM）、热重分析（TGA）等测试手段对复合薄膜进行表观形貌和热性能分析,借助万能材料试验机、接触角测量仪等仪器对薄膜进行力学性能、耐水性能、吸湿性能等分析。结果 以APTES改性MCC后的MMCC(MCC与APTES质量比5∶1)掺入淀粉所制备的薄膜MMCC-2/ST,复合薄膜拉伸强度较原淀粉膜（Native Starch Film, ST）提高了230%,水接触角为106.4°,相较于原淀粉膜（Starch Film, ST）提高了60.8°。结论 通过实验表明,MMCC对淀粉基薄膜的力学性能、耐水性能等有较好提升,从而拓宽了淀粉基薄膜在包装...     

Amine-modified silica surface applied as adsorbent in the phenol adsorption assisted by ultrasound

Abstract

Phenolic compounds are toxic pollutants that are harmful to the human body and aquatic environments, with carcinogenic potential and frequently found in industrial effluents at high levels. Adsorption processes are often employed for the removal of these compounds. Mesoporous materials based on modified silica with amine have been used as adsorbents and can be considered promising for this job due to its high selectivity and better adsorption capacity when compared to materials without any modifications. In addition, adsorption studies can be performed using ultrasound as a mixing mechanism, improving mass transfer through cavitation and acoustic current. In this context, the goal of this study is to modify the surface of mesoporous silica with 3-aminopropyltriethoxysilane (APTES) and to evaluate its efficiency in the adsorption of phenol in an ultrasonic bath. In the phenol adsorption experiments, the Si-APTES showed higher adsorption capacity (12?mg g^?1) than the SiO₂ (2?mg g^?1). The kinetic models of pseudo second-order have shown to be good fits to the experimental data. The adsorption equilibrium data of the phenol on the materials studied were best described in the Langmuir isotherm.