Structure, dynamics and interactions of complex sol-gel hybrid materials through SSNMR and DSC: Part II, ternary systems based on PE-PEG block copolymer, PHS and silica

This work is the second part of a study aimed at understanding in more depth structure, dynamics, interactions and correlations between morphology and barrier properties against oxygen diffusion of complex PE-PEG/PHS/SiO₂ hybrids prepared through a sol-gel process. Using a combined DSC and solid-state NMR approach, including ¹³C and ²⁹Si experiments and ¹H ultra-fast MAS spectra, the structural, phase and interaction properties of three PE-PEG/PHS/SiO₂ samples with different compositions, exhibiting different barrier performances, have been investigated, also taking into account the results obtained for the simpler one- and two-component systems (Part I). While the structure of the silica domains has been found to be not affected by composition, many differences have been observed concerning the phase and dynamic properties of the organic components (PE and PEG crystallinity and mobility of their amorphous domains) and the inter-component interactions (strength of the hydrogen bonds between PHS and both silica and PEG and PHS/PEG miscibility). In particular peculiar phase and interaction properties of the sample exhibiting the best barrier properties have been identified and characterized.     

自生CO2泡沫驱油可行性研究

针对低矿化度,中低温的稠油油藏,开展自生CO<,2>泡沫驱油的可行性研究.通过大量的实验,筛选出了稳定高效、经济可行的生气体系以及性能优越的起泡剂和稳泡剂,得到了优良的自生泡沫体系配方.考察了温度对自生泡沫体系起泡性和稳泡性的影响,并对自生CO<,2>泡沫体系的粘度的长期稳定性和油水界面张力性质进行了测定.实验结果表明...     

强碱三元体系界面张力影响因素研究

界面张力是评价三元复合体系的重要指标。从三元复合体系表面活性剂浓度、碱浓度、聚合物浓度、水质矿化度以及体系稳定性等方面进行研究,得出不同表面活性剂、碱浓度下,三元复合体系界面张力先降低后升高,矿化度对界面张力的影响很大。0.30%S（表面活性剂）＋1.2%A（碱）＋1650 mg/LP（聚合物）三元复合体系的界面张力在...     

石油磺酸盐及其与脂肪醇醚磺酸盐复配体系的耐盐性能和界面性能

通过对胜利馏分油的磺化制得一种石油磺酸盐(PS),并对其与不同碳链脂肪醇醚磺酸盐(AnESO,EO=3,n=1214,16,18)复配体系的耐盐(NaCl、CaCl2)性能和界面性能进行了研究。结果表明:(1)PS耐盐性能较差,当NaCl质量浓度达到30 g/L或CaCl2质量浓度达到0.15 g/L时,即有沉淀生成,且与胜利原油间的界面张力值较高(≥10-1 mN/m)。(2)将PS和AnESO以m(PS)∶m(AnESO)=9∶1复配,复配体系的耐盐性能均明显提高。其中PS/A18ESO复配性能最好,复配体系NaCl质量浓度能达到80 g/L,CaCl2质量浓度则达到2.4 g/L;而且界面张力在一定NaCl和CaCl2含量下可以降至10-2 mN/m数量级。     

树脂基复合材料耐海水性能研究进展

树脂基复合材料以其轻质、高强、高模等特性广泛应用于航空航天、海洋工业等领域。本文介绍了近年来国内外关于树脂基复合材料耐海水性能的研究进展。从纤维、基体和界面三个方面分析了复合材料耐海水腐蚀原理,综述了温度、浸泡时间和孔隙率等因素对复合材料耐海水性能的影响,最后提出了改善复合材料耐海水性能的途径。     

硫酸盐型孪连表面活性剂的界面性能研究

考察了自制的三种高纯度双直链烷基硫酸盐型孪连表面活性剂的界面性能和驱油性能。结果表明,双直链烷基硫酸盐型孪连表面活性剂的CMC在10-5~10-6mol/L之间;随着表面活性剂浓度的增加,界面张力达到平衡时所需要的时间明显延长;随着联接基团碳链长度的增加,油水界面张力先增大再减小;此类孪连表面活性剂具有非常好的抗一价盐二价盐的能力;用2C13-C2-2C2SO4Na作为驱油剂进行驱油实验时,可以使采收率在水驱基础上提高5%以上,具有比较好的驱油效果。     

N-[(4-溴-3,5-二氟)苯基]马来酰亚胺合成

以马来酸酐和4-溴-3,5-二氟苯胺为原料,对甲苯磺酸为催化剂,甲苯/DMF为混合溶剂,采用溶剂共沸法,制备了N-[(4-溴-3,5-二氟)苯基]马来酰亚胺,用FTIR、1HNMR和13CNMR对产物进行了结构表征,并对合成工艺进行优化,所得适宜工艺条件(以4-溴-3,5-二氟苯胺38.6 mmol计):催化剂对甲苯磺酸用量0.877 8 g,n(马来酸酐)/n(4-溴-3,5-二氟苯胺)=1.2,胺化反应时间为1.5 h,环化反应时间为2 h,产率可达92.6%。     

新型核-壳改性剂N-AIM对PMMA性能的影响

通过乳液聚合方法制备了不同橡胶粒径和橡胶相组成比的新型核-壳丙烯酸酯类抗冲改性剂（N-AIM）,将其与聚甲基丙烯酸甲酯（PMMA）进行熔融共混,得到了PMMA/N-AIM共混物。对PMMA/N-AIM共混物的形态结构、冲击性能和光学性能分别进行了考察。通过透射电镜（TEM）分析表明,橡胶粒径为100 nm时改性剂在基体中发生聚集,大于100 nm时均可均匀分散在基体中;冲击测试结果表明,随着N-AIM橡胶粒径的增加,共混物的冲击强度先增大后减小;光学测试表明橡胶组成比影响共混物的光学性能。     

First Phase Selection in Solid Ti/Al Diffusion Couple

用热压法制备Ti/Al扩散偶,并在525,550,575,600℃进行热处理。结果表明:当Al未完全消耗时,TiAl3是Ti/Al界面处唯一的产物,TiAl3向Al箔一侧长大,Ti箔中没有检测到Al原子的存在。从固溶体的溶解度极限,Al、Ti和TiAl3的晶格失配度,以及新相形成所增加的界面能3个方面解释TiAl3的首先生成。Ti在Al中的溶解度极限很小,Al(Ti)固溶体很容易生成,以及Al、Ti和TiAl3的密排面错配度很小,促使TiAl3优先形核。在所有Ti-Al化合物中,形成TiAl3所增加的界面能最少,有利于TiAl3优先形核长大。由于动力学的不稳定性,其他Ti-Al化合物的生成与长大受到抑制。     

A surface analytical study of the formation and adhesion of chromium films on alumina

Chromium-alumina bonding was characterized by using surface analysis techniques. The metal-ceramic interface was produced by vapour deposition of the metal at room temperature in an ultra-high vacuum chamber equipped with AES (Auger electron spectroscopy), EELS (electron energy loss spectroscopy), and XPS (X-ray photoelectron spectroscopy) facilities. Two kinds of alumina surface were used as the support for Cr condensation: a stoichiometric (1×1) α-Al₂O₃ surface (called the perfect surface or class a) and an oxygen-deficient surface giving rise to LEED patterns (called the reduced surface or class b). It is shown that on perfect surfaces the Cr film grows layer by layer but on reduced surfaces a three-dimensional (3D) growth process is observed. These results are explained by a strong chemical interaction between Cr and the class a surface, and by 3D nucleation on defect sites on the class b surface. After ageing for a few days under vacuum, the thick Cr film deposited on the reduced surface delaminates. This behaviour can be interpreted as competition between Cr atoms and Al ions to form an interfacial oxide layer.