二甲酸钾的绿色合成

以甲酸和氢氧化钾为原料,不外加任何溶剂一步合成二甲酸钾。通过单因素实验,考察了原料配比、反应温度和反应时间对产品质量与收率的影响。采用正交实验进一步优化了合成工艺,确定了最佳工艺条件:n(HCOOH)/n(KOH)=2.2、反应温度70℃、反应时间30 m in,在该条件下,二甲酸钾产品收率达98%以上。所得产品经红外光谱分析及熔点测定,其结果与文献报道一致。反应过程绿色化,有很好的原子经济性。     

Laminated Polymer-Encapsulated Halide Perovskite Photoconductors

Herein, a simple, solvent-free method to fabricate polymer-encapsulated halide perovskite photoconductors is described. Dry mechanochemical synthesis is used to prepare CsPbBr₃ in the presence of poly(butyl methacrylate) (PBMA). The resulting composite powder is then heated and pressed into a free-standing disk with a thickness controlled by a metallic spacer ring. The disk can be laminated on a glass substrate patterned with interdigitated electrodes, resulting in a planar photoconductor device. The best photoconductive performance is obtained for disks that consist of 75 wt.% CsPbBr₃ in PBMA, reaching a detectivity of ≈2 × 10¹¹ Jones. Moreover, by adjusting the thickness of the disk, narrowband detectors can be obtained due to charge collection narrowing. Depending on the thickness of the pressed disk, the position and width of the detectivity peak can be tuned. At last, the disks are tested as possible absorber materials for X-ray detectors, where ow detection limit, and fast and linear response are measured for perovskite-polymer disks with 50 wt.% perovskite content. This work shows a simple and versatile approach toward the fabrication of halide perovskite photodetectors, which can be carried out in air and without the use of solvents.     

无溶剂合成含二茂铁基查尔酮

在无溶剂条件下,以乙酰基二茂铁、芳醛为原料,以NaOH/无水K₂CO₃为催化剂,室温研磨反应合成含二茂铁基查尔酮,产物的结构经IR,¹H NMR及¹³C NMR得以确证。同时优化了反应条件,确定了最佳反应条件:n(乙酰基二茂铁)∶n(芳醛)为1∶1.2,催化剂NaOH/K₂CO₃用量10%mol,室温研磨5～10 min,二茂铁基查尔酮的产率达到89%以上。     

新型耐高温无溶剂环氧胶粘剂的研制

采用DTGM53、DDRS3521这2种多官能环氧树脂,以低黏度的甲基四氢苯酐为固化剂,在促进剂E-24作用下,制备了综合性能优异的新型耐高温无溶剂环氧胶粘剂。同时,对该环氧胶粘剂的黏度、凝胶化时间、粘接性能、活化能等作了系统的研究。结果表明,该胶粘剂具有优异的高温拉伸剪切强度,200℃时高达16.1 MPa。     

单分散无溶剂纳米SiO2流体对环氧树脂的改性

以纳米粒子SiO₂为核、表面活性剂N,N-十二基-N-甲基-N-(3-三甲氧基甲硅烷基丙基)氯化铵(SID3392)为颈状层、聚(乙二醇)4-壬基苯基醚3-磺丙基钾盐(PEGS)为冠状层,制备出了无溶剂纳米SiO₂流体。无溶剂纳米SiO₂流体为牛顿流体,在室温下具有较低的黏度,在26.5 ℃时其黏度为4.3 Pa·s,无溶剂纳米SiO₂流体中SiO₂的含量为13.65wt%。将该无溶剂纳米SiO₂流体加入环氧树脂中,制备了无溶剂纳米SiO₂流体/环氧树脂复合材料。TEM结果表明: 无溶剂纳米SiO₂流体在环氧树脂基体中具有良好的分散性。DSC测试表明: 无溶剂纳米SiO₂流体的加入会略微降低环氧树脂的固化温度。当纳米SiO₂流体加入量为2.5wt%时,复合材料的冲击性能提高了164.7%,玻璃化温度提高了15.4 ℃。断面SEM结果显示无溶剂纳米SiO₂流体能够提高环氧树脂的韧性。     

无溶剂环氧煤焦沥青涂层在土壤中的电化学行为

目的研究无溶剂环氧煤焦沥青涂层在饱和水含量土壤中的电化学行为。方法将无溶剂环氧煤焦沥青涂层涂覆在Q235碳钢上,测试不同厚度和不同埋设时间涂层的开路电位和交流阻抗谱图,探索涂层厚度和埋设时间对涂层电化学行为的影响。利用SEM分析基体表面腐蚀产物的元素组成,探索侵蚀性物质是否到达基体表面参与腐蚀历程。结果涂覆200μm厚涂层的Q235碳钢的稳定开路电位约为-0.37 V,与裸Q235钢相比,自腐蚀电位正移了0.28 V。随着涂层厚度的增加,开路电位呈上升趋势,容抗弧半径增大,涂层对侵蚀性溶液的屏蔽阻挡能力提高。随着在土壤中埋设时间的延长,容抗弧半径减小,吸水率增大,涂层的防护性能有所下降,但低频阻抗模值仍高达8.8×107Ω·cm2。能谱分析显示,Q235碳钢表面未出现Cl-等侵蚀性物质。结论无溶剂环氧煤焦沥青涂层在土壤环境中是有效的屏蔽层,可对Q235碳钢基体起到有效的防护作用。     

一种无溶剂饮水舱防腐涂料的毒性研究

目的 探讨一种无溶剂饮水舱防腐涂料的毒性作用.方法 急性经口毒性实验采用啮齿类动物急性固定剂量经口毒性实验一次限量法,剂量设为20000 mg/(kg BW).微核实验设5000、2500、1250 mg/(kg BW)3个剂量组、阴性对照组及阳性对照组,采用30 h给受试物法,检测骨髓嗜多染红细胞微核率.Ames实验...     

Solvent-Free One-Pot Synthesis of 1,8-Dioxo-Decahydroacridines by a [Et3NH][HSO4] Catalyzed Multicomponent Reaction

ABSTRACT

[Et₃NH][HSO₄] has been used as an effective catalyst for one-pot, three-component condensation of an aromatic aldehyde, 5,5-dimethyl-1,3-cyclohexanedione and ammonium acetate for the synthesis of 1,8-dioxo-decahydroacridines under solvent-free conditions. The present methodology offers several advantages, such as high yields, short reaction times, mild condition, and a recyclable catalyst with a very easy work-up.     

Physicochemical properties and film formation of the chitin hydrocolloid fabricated by a novel green process

Chitin is a valuable natural material, but its applications are limited because of its insolubility in water. Size reduction of natural materials has been found to offer certain benefits, including enhancing dispersibility. We employed media milling to produce a chitin micro-suspension with water as the sole solvent, and to fabricate the chitin film. The particle size and molecular weight were decreased from 96.86 to 21.95 μm and 173 to 75 kDa (M_n), respectively, post milling; however, the degree of deacetylation slightly increased (from 21.26 to 24.31) with milling time. Moreover, limited water-soluble fractions were generated, the quantity (1.5–2.0% d.b.) and molecular weight (M_n 15–34 kDa) of which were characterized. These fractions enabled the formation of a chitin film through the induction of hydrogen bonds. The particle size affected the morphology and mechanical properties of the film. The fabricated chitin film had tunable thickness (61.3–80.7 μm), tensile strength (38.95–64.61 MPa), elongation (0.93%–2.16%), Young's modulus (2994–4246 MPa), WVP (12.04–17.79 g mm/m² day kPa), swelling ratio and surface smoothness. This novel method for fabricating chitin films through aqueous suspension can improve applications of chitin in packaging and particularly fulfill environmentally friendly requirements.     

无溶剂环氧防腐涂料的制备和性能研究

开发了一种以腰果酚改性胺为固化剂的无溶剂环氧防腐涂料,介绍了环氧树脂、固化剂、稀释剂以及填料等原料的选择,探讨了环氧树脂与腰果酚改性胺的固化机理,并考察了硅烷偶联剂对涂层防腐性能的影响。检测结果表明,环氧树脂与腰果酚改性胺的固化主要以环氧基与胺基之间的反应为主;硅烷偶联剂可以提高涂层的附着力,有效地增强涂膜的耐水性。