Natural source compatibilizers for olive waste/recycled polypropylene matrix composites

A simple, environmentally friendly process was developed for surface hydrophobization of cellulose-rich waste to improve their compatibility with recycled polypropylene (rPP), helping reduce costs while recycling environmentally problematic waste such as solid olive waste (also called olive pomace). In this study, an improvement of the interfacial bonding strength between the hydrophilic waste particles and the hydrophobic matrix was achieved by surface hydrophobization of the waste using a ring-opening polymerization reaction of epoxidized soy-bean oil (ESBO) with SnCl₂ as a catalyst. The treatment on cellulose based filter paper led to a contact angle of 128°. The composite containing treated olive pomace has shown an increase in the elongation of 92% and an increase in the stress at yield of 15%, indicating improved compatibility.     

Multielemental evaluation of garbage bags by EDXRF

Garbage bags have been broadly used for collecting household waste in Brazil and worldwide. Many of these bags are made from recycled polymers, and the presence of harmful elements is a matter of concern. In this study, an energy dispersive X-ray fluorescence (EDXRF) approach for direct analysis of garbage bags is proposed. The concentrations of K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, Br, Rb, Sr and Pb were determined in 14 garbage bags of different brands purchased from local markets in Piracicaba, São Paulo State, Brazil. The EDXRF technique proved to be an effective technique for multielemental, environmentally friendly and direct garbage bag monitoring. For most samples, Ca and Ti presented at minor concentration ranges and K, Cr, Mn, Fe, Ni, Cu, Zn and Pb at minor and trace levels. The EDXRF limits of quantification were K: 220; Ca: 112; Ti: 42; Cr: 19; Mn: 13; Fe: 9.2; Ni: 5.7; Cu: 5.3; Zn: 5.2; Br: 12; Rb: 20; Sr: 28 and Pb:17 μg g^–1. The samples had variable thicknesses, with a superficial density variation of 1.5 to 23% among the triplicates. The trueness of the method was checked by analysing the National Institute of Standards and Technology standard reference material SRM2783.     

In‐situ thermal reduction and effective reinforcement of graphene nanosheet/poly (ethylene glycol)/poly (lactic acid) nanocomposites

This study aims to achieve a molecule‐level dispersion of graphene nanosheets (GNSs) and a maximum interfacial interaction between GNSs and a polymer matrix. GNS‐reinforced poly (ethylene glycol) (PEG)/poly (lactic acid) (PLA) nanocomposites are obtained by a facile and environment‐friendly preparation method. Graphite oxide and GNSs are characterized by atomic force microscopy, Raman spectroscopy, and X‐ray diffraction. Scanning electron microscopy shows that the state of dispersion of the GNS in the PEG/PLA matrix is distribution. The tensile strength and Young's modulus increases by 45% and 188%, respectively, with the addition of 4.0 wt% GNSs. The thermal stability of the GNS‐based nanocomposites also improves. Differential scanning calorimetry indicates that GNSs have no remarkable effect on the crystallinity of the nanocomposites. The effective reinforcement of the nanocomposites is mainly attributed to the highly strong molecular‐level dispersion of the GNSs in the polymer matrix. Copyright © 2014 John Wiley & Sons, Ltd.     

Self-assembling properties of glycolipid biosurfactants and their potential applications

Biosurfactants (BS) produced by a variety of microorganisms show unique properties (e.g. mild production conditions, multi-functionality, higher environmental compatibility) compared to their chemical counterparts. The numerous advantages of BS have prompted applications not only in the food, cosmetic, and pharmaceutical industries but in environmental protection and energy-saving technology as well. Among BS, “Glycolipid type” BS are the most promising, due to high productivity from renewable resources and versatile interfacial and biochemical properties. Mannosylerythritol lipids (MELs), which are glycolipid BS produced by yeast strains of the genus Pseudozyma, not only exhibit excellent surface activities but also self-assemble to form different lyotropic liquid crystalline phases such as sponge (L₃), bicontinuous cubic (V₂) or lammellar (L_α). They also show induction of cell-differentiation against human leukemia cells, and high binding affinity towards lectins and immunoglobulins. Recently, the cationic liposome bearing MELs has been demonstrated to increase dramatically the efficiency of gene transfection into mammalian cells. These features of BS should broaden the applications in new advanced technologies. The current status of R&D on glycolipid BS, especially their functions and potential applications, is discussed.     

水相中一锅煮、四组份反应高效合成多取代嘧啶类化合物

此文报道了一种室温下,水相中由丙二睛,二硫化碳,卤代烃和烷基异硫脲四组份、一锅煮反应合成多取代嘧啶类化合物的方法。该方法具有高效、反应条件温和、操作简单、适用范围广和环境友好等优点。     

智能水凝胶研究最新进展

综述了近几年国内外智能水凝胶研究现状,重点介绍了对pH、温度、光、电、磁和特定生物分子敏感的水凝胶的研究创新以及智能水凝胶在药物控释载体、组织工程支架、血红蛋白氧栽体、生物传感器、蛋白质检验等生物医学领域应用的最新进展.     

House bulb light-induced photochemical acetalization of carbonyl compounds catalyzed by Eosin Y

We have systematically studied the reactions of acetalization and found that high reaction efficiency can be achieved using cheap and readily available organic Eosin Y as catalyst. The reaction proceeds smoothly under house bulbs and shows excellent functional group tolerance. The substrates of the reaction system are compatible with aromatic aldehydes, aliphatic aldehydes, aromatic ketones, and cyclic ketones with high yields.     

可见光催化的交叉偶联放氢反应

光化学反应节能、洁净、节约的特点为发展原子经济、步骤经济的绿色环保合成化学注入了活力.我们借助可见光催化反应发展了一类新反应--可见光催化交叉偶联放氢反应.该反应不需要额外氧化剂的参与,直接实现两种不同碳氢键（或碳氢键和杂氢键）的直接偶联,生成新的碳碳键（或碳杂键和杂杂键）同时,氢气为唯一的副产物.相比于传统的合成方法,该策略在温和的反应条件下,避免了氧化剂的使用,减少了副反应的发生,近几年已被应用于多种化学键的构建.简要讨论可见光催化交叉偶联放氢反应的发展及其在有机合成领域的应用,期望能够更全面地理解这种新型催化模式,为开发绿色高效、步骤经济以及原子经济的合成策略和实际应用提供参考.     

非对称心理压力下的低碳环境友好技术国际转移博弈研究

在全球积极应对和适应气候变化的背景下,研究了心理压力和信息条件因素对低碳环境友好技术(LCEFT)转让企业与受让企业决策行为的影响。通过引入对谈判区间、还价策略和不同心理压力的假设,构造了非对称信息下的LEFCT转移讨价还价博弈模型,深入分析了收益贴现参数、心理压力参数和谈判区间等因素对博弈双方报价策略、还价策略以及成交价格所产生的影响。研究表明,心理压力和信息条件都会直接影响博弈双方的报价策略、还价策略和最终的成交价格,并得出了不同信息条件下受让企业“见好就收”和“对半侃价”的还价策略。本文为受让企业在应对全球气候变化中面对不同的心理压力和信息条件所应采取何种还价策略提供了一定的决策支持。     

Effective and Green One‐Pot Multicomponent Synthesis of Novel Derivatives of 4H‐Pyrans in the Presence of Hexamethylenetetramine as Catalyst in Water Medium

Hexamethylenetetramine catalyzes synthesis of new polyfunctionalized 4H‐pyrans by the reaction of aromatic aldehyde, malononitrile, and β‐keto esters via one‐pot three‐component procedure in water medium. Addition of reactants was performed by two methods led to achieve similar results. Using hexamethylenetetramine in catalytic amount not only represents the economic face of the reaction but also due to the use of water, a green and safe reaction condition is organized. Thus, the current strategy provides the benefits of high productivity, convenient operation, and environmental friendliness. The structure of all products were proved by elemental analysis, IR, ¹H NMR, and ¹³C NMR spectroscopy.