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《纤维素科学与技术》2015,(3):49-54
以木质素为原料合成木质素基染料分散剂,其制备工艺为:木质素经羧甲基化后,再以甲醛和亚硫酸氢钠进行羟甲基化和磺化反应,制备木质素基染料分散剂,并将其应用于分散红FB染料,进行分散性能及耐热稳定的研究。结果表明,当一氯乙酸用量为2.5%、羧甲基化时间为60 min、甲醛用量3%、羟甲基化温度100℃、磺化剂10%、羟甲基化时间50 min、磺化时间150 min时,所制备的分散剂的分散等级可达到5.0级,在150℃分散等级仍可达3.2级。 相似文献
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镍基高温合金陶瓷涂层的制备及性能表征 总被引:1,自引:0,他引:1
以Cr2O3粉、玻璃料及黏土为原料制成料浆,通过喷涂将其涂覆在镍基高温合金GH44的表面,采用热化学反应法于1050°C保温10min,熔烧制备出高温陶瓷涂层。通过扫描电镜和X射线衍射分析了高温陶瓷涂层的表面和截面形貌以及相组成,对涂覆陶瓷涂层的镍基合金的抗热震性能、抗氧化性能以及高温疲劳性能进行了测试。结果表明,陶瓷涂层结构致密,与基体结合牢固,具有良好的抗热震性能。涂覆陶瓷涂层的镍基合金其高温抗氧化性相对于基体提高了6倍以上,其高温疲劳性能明显改善。 相似文献
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基于碳酸酐酶(CA)-芳香磺酰胺抑制剂相互作用的原理,本文合成了一种新的Zn2 荧光探针2-丹磺酰氨乙基-1-DPA(2-[5-[二甲基胺]1-萘磺酰氨乙基]1-N,N-二吡啶甲基胺)(1),其中Zn2 对荧光团丹磺酰胺有很好的亲和力,N,N-二(2-吡啶甲基)乙二胺作为接受体对Zn2 具有很好的选择性。在生理条件下(pH7.4),λx=334nm,λem=540nm。加入Zn2 后,λex基本不变,λem蓝移到520nm,荧光强度增大将近4倍。表观解离常数(Kd)在纳摩尔范围内,在生物应用中具有足够的敏感性。另外,多种生物体中重要的金属离子对1的荧光没有影响,如Ca2 、Mg2 等。Zn2 -1络合物的荧光强度受pH变化的影响不大,特别是在pH6-9之间影响很小。1的光物理性质表明它是一种对Zn2 有特殊选择性并有效的荧光探针。 相似文献
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《精细化工中间体》2015,(3):67-69
采用碳基固体酸为催化剂,顺丁烯二酸酐、1,3-丙二醇、异辛醇为原料进行单酯化和双酯化反应,再与亚硫酸氢钠进行磺化反应,生成1,3-丙二醇双磺基琥珀酸异辛酯钠(GSS362)。在反应优化条件下,重复实验的产物收率均在95%以上。对产物结构进行了IR光谱和质谱表征分析。测定了产物的性能,临界表面张力(γCMC)19.9 m N/m、临界胶束浓度(CMC)0.869×10-3mol/L、乳化力29.7 min(1.0%)、渗透力3.4 s、耐硬水能力35.5 min;毒性较低,为弱致敏物;不具有爆炸性,撞击敏感度实验结果为-;在实验条件下28 d生物降解结果为47%。 相似文献
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以烯丙基醇聚氧乙烯醚500(APEG-500)、羧酸单体 (丙烯酸和衣康酸)、二甲基二烯丙基氯化铵(DMDAAC)等为原料,合成了具有不同羧酸单体的两性聚羧酸盐水煤浆分散剂。采用FTIR、1HNMR对分散剂的结构进行表征,并结合水煤浆黏度、XPS、Zeta电位、接触角、稳定性等测试,讨论了不同羧酸单体对分散剂的分散性能的影响,探究了分散剂与煤粒表面的作用机理。结果表明:当DMDAAC用量为单体质量之和的6.0%时 ,两性聚羧酸盐分散剂对水煤浆的表观黏度降低效果优于阴离子型的聚羧酸盐分散剂;羧酸单体为衣康酸的分散剂性能更优,使陕西榆林煤最大固体质量分数达到66.5%,Zeta电位由-20.8 mV变化到-31.9 mV,吸附膜厚度和饱和吸附量分别为2.56 nm和3.23 mg/g,对煤粒的润湿性更好,浆体的稳定性显著提高,表明双羧基比单羧基更能提高分散剂性能。 相似文献
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Environmental concerns have stimulated interest in utilizing plant-derived materials in various industrial fields. The main objective of the present study was to synthesize a new type of high-performance lignin series dispersant of coal–water slurry (CWS) from wheat straw alkali lignin (WAL), and determine the affecting factors in the reaction and the application performance for CWS preparation. The experimental results showed that the inherent viscosity and the sulfonic group content of the modified wheat straw alkali lignin (MSL) are the key factors affecting its dispersing effect for CWS. In the reaction, the reactant mass concentration and the sulfonating agent amount were changed to obtain the MSL with different inherent viscosities and sulfonic group contents, and the MSL with intermediate inherent viscosity (6.0 ml/g) and higher sulfonic group content (1.80 mmol g− 1) was found to have excellent dispersing effect for CWS. The MSL obtained from optimized process was used as dispersant for CWS preparation, the studies of the properties of CWS showed that MSL has similar dispersing effect with naphtalenesulfonate–formaldehyde condensate, and far better dispersing effect than lignosulphonate. Recently this kind of new dispersant has been applied in several power plants in China. 相似文献
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The preparation of dispersants with carboxyl groups from acid lignin (a byproduct in the saccharification process of woody materials that are renewable resources) was investigated, and their dispersion efficiency was evaluated. In this study, sulfuric acid lignin (SAL) was selected as a representative acid lignin. To convert SAL to water‐soluble polymers, it was first subjected to phenolation with sulfuric acid to enhance its chemical reactivity. The introduction of a carboxy group was carried out with two methods. One was carboxymethylation with bromoacetic acid, and the other was the Mannich reaction with glycine, sarcosine, and iminodiacetic acid. The carboxymethylation product [carboxymethylated phenolized sulfuric acid lignin (CP‐SAL)] with 1.4 carboxymethyl groups per phenolated phenylpropane lignin base unit was soluble in water. The Mannich reaction products were also soluble in water with a lower addition of carboxyl groups than that for CP‐SAL. Surprisingly, all the prepared water‐soluble polymers possessed a higher dispersibility for gypsum paste than commercial lignosulfate. This may be due to the higher molecular weights of acid lignin derivatives. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 2508–2513, 2005 相似文献
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采用超滤方法对木质素磺酸钠进行分离得到3种不同分子量级份。采用凝胶渗透色谱、紫外光谱、电位滴定等方法研究各级份的结构特征及其对分散染料性能的影响。结果表明,随着分子量的增加,木质素磺酸钠颜色加深、纯度提高,分子结构中愈创木基含量增多,酚羟基、磺酸基和羧基的含量降低;高分子量木质素磺酸钠对分散染料具有更优的分散性和高温稳定性,染料上染率也随其分子量的增大而增加,且当木质素磺酸钠浓度较高时,分子量增大,对纤维沾污减弱。木质素磺酸钠对染料的还原破坏作用与分子量和酚羟基含量有关,采用截留分子量大于2.5×103的膜提纯的木质素磺酸钠级份对染料还原性最低,还原水解率由未提纯时的26.0%降为6.9%,且该级份木质素磺酸钠具有最优的匀染性能。 相似文献
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以碱木质素(alkali lignin,AL)、聚乙烯亚胺(polyethylenimine,PEI)为碳源,其中PEI不仅作为碳源还作为表面钝化剂,在H2O2氧化下通过一步水热法绿色、高效制备高荧光、寿命长和多氨基化功能碳点(alkali lignin/polyethylenimine carbon dots,AL/PEI-CDs)。探究了碱木质素/PEI质量比、水热温度和水热时间等因素对碳点荧光强度的影响,确定了最佳的反应条件,同时考察了AL/PEI-CDs对pH的敏感性及稳定性。采用紫外分光光度计(ultraviolet spectrophotometer,UV-vis)、荧光分光光度计、原子力显微镜(atomic force microscope,AFM)、高分辨透射显微镜(high resolution transmission electon microscopy,HRTEM)、傅里叶红外光谱仪(Fourier transform infrared spectroscopy,FTIR)和X射线衍射仪(X-ray diffractometer,XRD),对AL/PEI-CDs的光学性质、形貌结构、化学结构和晶体结构等进行了表征分析。结果表明,在碱木质素/PEI质量比为1∶12、水热温度190℃、水热时间12h的条件下,合成的AL/PEI-CDs荧光量子产率为25.53%,荧光寿命为5.06ns,表面含有丰富的氨基和羟基,且粒径均一、水溶性好,有良好的稳定性,在最佳激发波长为ex=313nm下对应的发射峰位为405nm,稀释液在紫外灯下发出明亮的蓝光。本研究制备的碳点在离子监测和细胞代谢过程监测质子传感器中可能具有良好的应用前景。 相似文献
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《Journal of the European Ceramic Society》2022,42(15):6889-6897
TRISO particles with new coating layers was designed to adapt higher temperature. In this work, NbC coating layers were prepared by a novel two-step method: The original NbC coating layer was prepared from NbCl5 and C3H6 by chemical vapor deposition method. The flow rate of the C3H6 should be relatively low to avoid the C impurity. The NbC layer was then heated with carbon powders at high temperature. Since the C atoms can diffuse into the NbC coating layer and react with Nb2C at high temperature. The Nb2C impurity comes from the deposition was removed after the thermal treatment. The crystal of NbC layer grow up and has a change of preferred orientation at high temperature. The heat treatment has slight effect on the hardness of the pure NbC layer. Our result shows the NbC coating layer has good adaptability to the high temperature environment in VHTR. 相似文献
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利用热重分析法研究了蔗渣碱木素的热解特性,并利用TG-FTIR和Py-GCMS对碱木素的热解产物种类及分布规律进行了分析。结果表明,木素热解呈现宽温度区域,可分为4个阶段,主要裂解温度范围为200~500℃,在400℃左右失重率最大,残余物得率较高。TG-FTIR分析显示了木素热解过程中气体产物的释放规律,300~500℃为主要热解挥发阶段,大部分气体产物在400℃左右产率达到最大。Py-GCMS分析表明,木素的热解产物大致可分为杂环、苯类芳香族、酚类芳香族、酯和酸等化合物,在主要热分解阶段,随着热解温度的升高,苯类和酚类芳香族化合物的含量增多,600℃时酚类物质的含量最高。 相似文献
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为了揭示羧甲基化碱木质素CML较磺化碱木质素(SAL)对农药具有更好分散性能的原因,测定了CML和SAL的亲水基含量、相对分子质量及纯水在木质素涂层的接触角,发现CML的亲水性弱于SAL。对比了两种木质素分散剂在多菌灵颗粒上的吸附等温线,发现CML的吸附量比SAL大,并采用Langmuir、Freundlich方程进行拟合,可知CML的吸附能力大于SAL,说明木质素与农药之间的吸附可能以疏水吸附为主。进一步采用Gaussian模拟计算木质素分散剂与多菌灵的π-π吸附作用力,结果表明羧甲基化碱木质素更易与农药形成稳定π-π作用,进一步促进吸附。亲水性较弱的CML由于与农药具有更强的吸附亲和力,因而吸附量大,对农药颗粒Zeta电位的提高更大,从而具有更好的分散性能。 相似文献
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以酶解木质素、三聚氰胺和甲醛为原料,通过接枝反应制备三聚氰胺改性酶解木质素(MEHL),并研究MEHL对银离子的吸附性能。接枝反应的研究结果表明,三聚氰胺和甲醛的添加量对产率有很大影响。酶解木质素、三聚氰胺、甲醛质量比为10:6:6,于90℃下反应4 h,所制得的MEHL的产率可达83.7%。红外光谱、热重和元素分析的结果表明,三聚氰胺成功接枝到酶解木质素分子上。MEHL的含氮量由酶解木质素的0.81%提高到18.55%。银离子的吸附研究表明,MEHL对银离子表现出很好的吸附性能。在银离子初始浓度为0.16 mol·L-1,在MEHL用量为50 mg,吸附温度为30℃时吸附36 h,MEHL对银离子的吸附容量为944.1 mg·g-1。 相似文献