高交联大孔吸附树脂氯甲基化研究

以无水ZnCl2为催化剂,以自制1,4-二氯甲氧基丁烷(BCMB)为氯甲基化试剂,对高交联度的非极性大孔吸附树脂D101进行氯甲基化反应研究。得到该氯甲基化的最佳工艺条件:m(D101)∶m(BCMB)∶m(CCl4)=1∶4∶18.6,溶胀时间12h,反应温度50℃,反应时间14h,以无水ZnCl2为催化剂,在该工艺条件下制得氯质量分数为4%的树脂,为以后树脂的改性、功能化和进一步研究大孔吸附树脂吸附分离规律提供了实验基础。     

Electroplating synthesis and electrochemical properties of macroporous Sn-Cu alloy electrode for lithium-ion batteries

Macroporous material of Sn-Cu alloy of different pore sizes designated as anode in lithium-ion batteries were fabricated through colloidal crystal template method. The structure and electrochemical properties of the macroporous Sn-Cu alloy electrodes were examined by using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and galvanostatic cycling. The results demonstrated that the electrodes of macroporous Sn-Cu alloy with pore size respectively of 180 and 500 nm can deliver reversible capacity of 350 and 270 mAh g⁻¹ up to 70th cycles of charge/discharge. The cycle performance of the macroporous Sn-Cu alloy of 180 nm in pore size is better than that of the macroporous Sn-Cu alloy with 500-nm-diameter pores. It has revealed that the porous structure of the macroporous Sn-Cu alloy material is of importance to strengthen mechanically the electrode and to reduce significantly the effect of volume expansion during cycling.     

以聚苯乙烯为模板制备有序大孔氧化铝

采用少皂乳液聚合法成功制备了单分散的聚苯乙烯微球,以微球自组装后的聚苯乙烯胶体晶体为大孔模板,铝溶胶为前驱体填充模板,干燥焙烧除去模板后制备了氧化铝载体。用激光粒度仪、扫描电镜、X射线衍射和氮气吸脱附对聚苯乙烯胶体晶体和氧化铝载体进行了表征。结果表明:少皂乳液聚合法制备的聚苯乙烯微球具有粒径较小(100~350 nm)、单分散性好(0.005)、收率高(约80%)等优点;自组装的胶体晶体呈规则有序排列,微球表面光滑洁净,并以此为模板成功制备了具有三维有序结构的、大孔孔径可调的氧化铝材料。     

A million-channel reformer on a fingertip: Moving down the scale in hydrogen production

The present contribution reports the design, manufacture and experimental proof of concept of an ethanol micro-reformer for portable-fuel cell feeding. Through photo-assisted electrochemical etching, a silicon micromonolithic substrate with perfectly parallel cylindrical channels of 3.3 μm diameter was achieved (density of channels of ca. 4 × 10⁴ channels mm⁻²). The channel walls were coated with a cobalt-based catalyst. The resultant functionalized micromonoliths were implemented in a stainless steel microreactor including feed evaporation facilities and electrical heating. The unit was successfully tested for ethanol steam reforming under non-diluted feed conditions at 773 K, achieving high hydrogen specific production rates, high ethanol conversions (>80%) and adequate selectivity profiles, with H₂:CO₂ molar ratios of ∼3 and low CO outlet concentrations. A performance comparison was performed with two other reforming substrates with the same catalyst formulation, namely, a conventional cordierite monolith and a conventional stainless steel microreactor. Results show for the Si-micromonolithic reactor a remarkable improvement of the specific hydrogen production rate (per unit reactor volume and feed flowrate), operating at considerably reduced residence times, due to the increase in contact area per unit volume.     

大孔吸附树脂浓缩分离紫菜薹色素的研究

本文选用了四种大孔吸附树脂对紫菜薹色素进行浓缩分离研究,其中NKA-Ⅱ树脂效果较好。试验结果表明,用0.3%柠檬酸-60%乙醇溶液作为洗脱液,经吸附-解吸循环,色素的回收率可达92.8%,同时可将提取液中的色素浓缩10倍以上。     

负载铂纳米粒子大孔炭材料的无模板制备

研究了负载铂纳米粒子大孔炭材料的可控制备。淀粉和氯铂酸分别被用作碳源和铂源,采用两种不同的方法将铂注入基于淀粉凝胶的大孔炭。方法A：将淀粉凝胶块材浸入氯铂酸水溶液中,然后用硼氢化钠还原。方法B：在形成淀粉凝胶块材之前将氯铂酸加入前驱体中。研究发现：大孔炭的孔径和壁厚可以通过改变淀粉含量进行调节,产炭率从负载前的24%分别提高到37%（方法A）和44%（方法B）,凝胶在炭化过程中的体积膨胀也得到有效抑制。方法A得到的铂纳米粒子（平均粒径为3.5nm,粒径平均偏差为0.9nm）比方法B制备的（平均粒径为5.5nm,粒径平均偏差为1.8nm）粒径更小、粒径分布更窄。     

Photonic Crystals from Emulsion Templates

Macroporous titania, which undergoes transition to the rutile phase by calcination without collapse of the pore structure, is obtained by polymerizing a titania sol suspended around “colloidal crystals” of oil droplets. The deformable template counteracts cracking of the titania phase. The Figure shows a scanning electron micrograph of a rutile sample with 200 nm pores obtained by the method described.     

Silica-supported carboxylated cellulose nanofibers for effective lysozyme adsorption: Effect of macropore size

Engineering hierarchical macro/mesoporous structures that offer an abundance of accessible binding sites are highly desirable in protein adsorption processes. However, numerous significant challenges remain. Herein, cellulose nanofiber (CNF)-loaded macroporous silica (CNF-MPS) particles were successfully synthesized with a high degree of accessible binding sites by tuning the macropore size of the silica particles and loading a highly carboxylated CNF via smart and rational design. The as-prepared CNF-MPS particles exhibited a high negative charge (~−59 mV) and excellent protein adsorption ability (>1000 mg/g) in <5 min. Furthermore, tuning the macropore size influenced the CNF deposition either to the external surface or penetrating within the pores. As a result, the optimum macropore successfully enhances the adsorption capability to >1500 mg/g as a result of improved interconnectivity between the channels. Here exposed macropores of >100 nm allows ingress of protein to the interior structure that houses an abundance of binding sites comprising the dispersed CNF. Additionally, the adsorption kinetics, thermodynamics, and isothermal parameters were studied to analyze the mechanism of lysozyme adsorption. The adsorption process is confirmed to occur spontaneously at any temperature with a pseudo-second-order model describing the kinetic model, and CNF deposition affecting the heterogeneity of the binding sites.     

Recent Progress in the Synthesis of Porous Carbon Materials

In this review, the progress made in the last ten years concerning the synthesis of porous carbon materials is summarized. Porous carbon materials with various pore sizes and pore structures have been synthesized using several different routes. Microporous activated carbons have been synthesized through the activation process. Ordered microporous carbon materials have been synthesized using zeolites as templates. Mesoporous carbons with a disordered pore structure have been synthesized using various methods, including catalytic activation using metal species, carbonization of polymer/polymer blends, carbonization of organic aerogels, and template synthesis using silica nanoparticles. Ordered mesoporous carbons with various pore structures have been synthesized using mesoporous silica materials such as MCM‐48, HMS, SBA‐15, MCF, and MSU‐X as templates. Ordered mesoporous carbons with graphitic pore walls have been synthesized using soft‐carbon sources that can be converted to highly ordered graphite at high temperature. Hierarchically ordered mesoporous carbon materials have been synthesized using various designed silica templates. Some of these mesoporous carbon materials have successfully been used as adsorbents for bulky pollutants, as electrodes for supercapacitors and fuel cells, and as hosts for enzyme immobilization. Ordered macroporous carbon materials have been synthesized using colloidal crystals as templates. One‐dimensional carbon nanostructured materials have been fabricated using anodic aluminum oxide (AAO) as a template.