活性炭负载Pt-Ni双金属催化剂上甘油水溶液原位加氢反应性能

采用KBH4液相还原法制备了系列活性炭(AC)负载的Pt-M(M=Fe,Ni,Co,Zn,Cu)双金属催化剂,考察了该系列催化剂对甘油水溶液原位加氢制备1,2-丙二醇反应的催化性能.结果表明,当Pt负载量(质量分数)为2.0%,Pt/Ni质量比为1∶1时,在220℃和1.0 MPa氮气压力下反应8 h,2%Pt-2%Ni/AC催化剂上甘油转化率和1,2-丙二醇选择性分别达到98.7%和60.5%;且在5次重复使用过程中,催化剂保持较高的稳定性.采用氮气物理吸附-脱附实验、X射线衍射(XRD)、透射电子显微镜(TEM)、选区电子衍射(SAED)及X射线光电子能谱(XPS)等对催化剂的结构和形貌进行了表征.结果表明,粒径约为2 nm的纳米颗粒在活性炭载体上均匀分散,纳米粒子中金属多以还原态形式存在,Ni原子进入Pt晶格中形成的Pt-Ni物种使Pt与Ni之间表现出强相互作用力.通过比较Pt/AC,Ni/AC与Pt-Ni/AC双金属催化剂的催化性能,推断Pt能够促进甘油水溶液重整而Ni有利于氢解反应,Pt-Ni金属间协同作用是Pt-Ni/AC催化剂对甘油原位加氢反应具有优良催化性能的重要原因.     

甘油催化加氢制备1,2-丙二醇液相产物的气相色谱分析

采用气相色谱-电子轰击离子源质谱(GC-MS)与比较标准品色谱保留值技术,确定了甘油催化加氢制备1,2-丙二醇液相产物的组成。优化了气相色谱-氢火焰离子法(GC-FID)的色谱条件,使主产物与副产物同时达到最佳分离。以正戊醇为内标物,建立了同时检测甘油催化加氢产物中7种醇类化合物的气相色谱分析方法。在分析方法的线性范围内,各化合物加标回收率均在94.4%～112.6%之间,相对标准偏差(RSD)在1.5%～7.2%之间。反应产物中乙醇、异丙醇、丙醇和丙酮醇的方法最小检出限(LOD)小于0.05μg/g,乙二醇、1,2-丙二醇和甘油的LOD分别为0.21μg/g,0.23μg/g和0.25μg/g,线性相关系数均大于等于0.9957。     

温和条件下Au/HY催化剂催化氧化丙三醇制丙醇二酸

研究了不同载体负载的Au催化剂催化丙三醇水相选择性氧化制丙醇二酸.与Au/CeO2,Au/AC,Au/REY和Au/NaY催化剂相比,Au/HY上获得了高收率的丙醇二酸.在60°C和0.3 MPa氧气压力下,丙三醇转化率达98%,丙醇二酸收率为80%.表征结果表明,小尺寸的Au纳米颗粒对生成丙醇二酸有明显促进作用;反应过程中丙三醇先被催化氧化生成甘油酸,再被进一步氧化生成丙醇二酸.     

反应型非离子表面活性剂的制备及其组成和结构

以丙烯酸(AA)与硬脂酸单甘油酯(GMS)、油酸单甘油酯(A300)或油酸单山梨糖醇酐酯(Span 80)为起始物, 对甲苯磺酸为催化剂, 对苯二酚为阻聚剂, 制备了三类含有1-烯键的反应型表面活性剂. 通过反应体系中AA 的加料量及其残留量, 计算得到丙烯酸的转化率为91%以上, 制备的反应型非离子表面活性剂的收率达到80%以上. 用红外光谱(FTIR)、核磁共振氢谱(1H NMR)和质谱对反应产物的组成和结构进行了表征, 确认获得了三类目标产物. 将这三类表面活性剂作为流滴剂与聚乙烯发生接枝反应后, 提高了聚乙烯的结晶温度, 降低了水在聚烯烃膜表面的接触角, 解决了聚乙烯农用棚膜的流滴期短的问题.     

甘油骨架上含芳硒基的替加氟硫代磷脂缀合物的合成及生物活性

以O-(2-邻苯二甲酰亚氨基)乙基-1,3,2-二氧磷杂环戊烷硫代磷酸酯1及2-邻苯二甲酰亚氨基乙醇环甘油硫代磷脂缀合物2为模型,研究开环反应的条件.结果表明,在室温下,甲醇对化合物1中1,3,2-二氧磷杂环戊烷中的磷原子的亲核进攻,生成O-甲基-O-羟乙基-O-(2-邻苯二甲酰亚氨基)乙基硫代磷酸酯3,但是在此条件下,甲醇与化合物2不反应.在室温下,以异丙醇作溶剂,苯硒酚与化合物2不反应.在氢氧化钾存在下,以异丙醇/水作溶剂(体积比20:1),在室温下,硒酚可以有效地进攻中化合物2中1,3,2-二氧磷杂环戊烷中的碳原子生成相应的开环产物.按照这一反应条件,顺利实现了硒酚对N¹-(2-呋喃基)-N³-羟烷基-5-氟脲嘧啶硫代环甘油磷脂缀合物的亲核开环,生成甘油骨架的端碳原子上带有芳硒基新颖的磷脂核苷缀合物.对开环反应的机理进行了探讨.体外细胞毒性试验结果表明:产物对膀胱癌细胞T-24、胃癌细胞BGC-823的恶性增殖抑制效果优于替加氟;但对正常肝上皮细胞毒性也大于替加氟.     

Electro-Motive Forces Generated in Concentration Cells of LiCl-Glycerol Solutions

Abstract

Mean ionic activity coefficients of LiCl in Glycerol have been calculated in the concentration range 0.5-500mol.m^-3, using the concentration cell technique. Up to the limit of the Debye-Huckel theory (C ≤ 1 mol·m^-3), the experimental values lie below the limiting line, showing that the measured Electro-Motive-Force might have been false by using our previous cell design. An alternative method based on Fuoss Paired Ion Model has been used to deduce the theoretical data, and consequently, the values of the EMF'S. By comparing these data to those obtained experimentally with KCI and NaCl, we find that they are consistent with the results in aqueous solutions.     

A sustainable one-pot synthesis of cinnamyl acetate in triacetin

A sustainable one-pot synthesis of cinnamyl acetate from cinnamaldehyde is demonstrated for the first time using immobilized Baker’s yeast and free or immobilized acid as catalysts and triacetin as solvent. Employing the immobilized yeast and Amberlyst-36 allowed full conversion and 91% selectivity for cinnamyl acetate after 96 h at room temperature, and both the catalysts and triacetin were successfully recycled.     

Early ultrastructural events of skeletal muscle damage following cardiotoxin-induced injury and glycerol-induced injury

In this study, we investigated the early changes of skeletal muscle damage in response to injuries induced by cardiotoxin (CTX) and glycerol by using both light microscopy and transmission electron microscopy. Normal, non-dystrophic, adult male mice were used in this study. Tibialis anterior (TA) muscles were injected either with CTX or glycerol. Samples were collected at intervals starting from 1 h up to 4 days after injury. Injured muscles were subjected to both histological and ultrastructural analyses. CTX-induced injury caused mitochondrial accumulation and swelling followed by lysis, while glycerol-induced injury caused accumulation of vesicles with focal disruption of the basal lamina, indicating that the injuries have different mechanisms of damage to myofibers. Moreover, inflammatory cells, including neutrophils and macrophages, were recruited earlier and in larger numbers after CTX-induced injury than after glycerol-induced injury. On the other hand, satellite cells (SCs) activation started at 6 h after both injuries, as indicated by an increase in both the length and cytoplasmic-to-nuclear ratio. However, there were significantly longer SCs with a higher cytoplasmic-to-nuclear ratio in the CTX-injured muscles than in the glycerol-injured muscles at day 4. In conclusion, our results demonstrated a difference between CTX and glycerol in their damage to myofibers; CTX damages myofiber mitochondria, while glycerol damages the myofiber cell membrane and alters osmosis. In addition, CTX-induced injury caused earlier and more extensive inflammatory infiltration than did glycerol-induced injury. This study is the first study to shed light on the early events following skeletal muscle injury induced by CTX and glycerol.     

All‐Atom Molecular Dynamics Simulation of Structure and Diffusion of Hydrophilic Antistatic Agents in Polypropylene

Glycerol monostearate (GMS) is an additive widely used in plastic industry for its good ability to improve the wettability and antistatic property of polymer surfaces. Based on GMS, we propose five additives of different polarity by attuning the number of oxyethyl groups. All‐atom molecular dynamics simulations of these additives in polypropylene (PP) matrix are carried out at temperatures of 300 K, 350 K and 400 K. Detailed molecular conformations are obtained and analyzed. Due to the gauche effect of the dihedral angles, the polar parts of these additives form helix structures. The diffusion coefficient of the additives depends on their molecular conformations and decreases monotonously with increasing polarity. These results are expected to be helpful in rational design of hydrophilic antistatic agents in polymeric materials.     

Effect of glycerol and its analogs on polyhydroxyalkanoate biosynthesis by recombinant Ralstonia eutropha: A quantitative structure–activity relationship study of chain transfer agents

Triglycerides such as plant and vegetable oils are desirable feedstock for the fermentative production of polyhydroxyalkanoate (PHA) because the weight yield of PHA from triglycerides is higher than that obtained from sugars. However, glycerol, a multi-hydroxy component of triglyceride, is known to function as a chain transfer (CT) agent in PHA polymerization, resulting in the formation of low-molecular-weight PHA. In this study, we evaluated how glycerol alters the molecular weight of PHA using recombinant Ralstonia eutropha as a practical host for PHA production. We demonstrated that glycerol has the ability to reduce molecular weight of PHA, even as a component of triglyceride. Furthermore, various alcohols that are structurally related to glycerol were examined for their reducing abilities to perform a quantitative structure–activity relationship (QSAR) study. It was found that alcohols with higher hydrophobicity (log P) exhibited higher reducing ability for PHA molecular weight. Glycerol, a less hydrophobic alcohol, was able to reduce PHA molecular weight; however, the efficacy was relatively weak among the examined alcohols.