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采用次氯酸钠漂白造纸用棉短绒黑浆 总被引:1,自引:0,他引:1
<正>次氯酸钠,分子式NaClO,俗称漂白液,为强碱弱酸盐,是一种能完全溶解于水的浅黄色液体,不易久存,有效氯不低于10%。次氯酸钠溶于水后才能真正发挥作用。它与水反应的方程式为NaClO+H_2O=NaOH+HClO。HClO具有强氧化性和漂白能力,也可 相似文献
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本文选用较高浓度的次氯酸钠溶液在煮沸状态下溶解纤维素纤维的方法,使次氯酸钠可以应用于对氨纶与纤维素纤维混纺织物以及棉腈等混纺织物的定量分析,其试验准确度和精密度均较好,且绿色环保。 相似文献
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本文探索了棉织物次氯酸钠冷轧堆前处理工艺,结果表明,只要加工液中有效氯的浓度保持在一定浓度范围内,不必另加烧碱,就可进行浸轧加工;后处理有两种不同方法供选择;影响棉织物毛效的因素中,果胶的影响比蜡状物质大。 相似文献
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Various aspects of the glycolic oxidation of the glucose units of starch with stoichiometric amounts of sodium hypochlorite applying sodium bromide as the catalyst have been investigated. The main objective of the study was to optimize the reaction conditions for the preparation of dicarboxy-starch and to establish the calcium sequestering capacity of the material. The products, polycarboxylates, are obtained in high yields (90-95%) and they have a sequestering capacity up to 1.4 mmole Ca/g, which is somewhat higher than that of the materials obtained in a non-catalyzed oxidation. This result is attributed to the facts that the reaction with sodium bromide may be carried out at higher pH (>9) than the non-catalyzed reaction and that a relatively low concentration of hypochlorite throughout the process could be maintained. In this way the decomposition of hypochlorous acid/hypochlorite, especially occurring at high concentration of hypochlorous acid at lower pH (6-8) is prevented. Other advantages of this procedure are the colourless appearance of the materials and the higher reaction rate. The feasibility for largescale preparation follows from the results of a few exploratory experiments, including an electrochemical preparation. 相似文献
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为保证次氯酸钠(NaClO)溶液循环使用后的杀菌效力,研究黄瓜切片、油菜连续加样对次氯酸钠(NaClO)溶液杀菌效果的影响,同时探讨油菜和黄瓜汁液对NaClO 溶液的氧化还原电位势(ORP)值影响。结果表明:切片黄瓜汁液渗出较多,多于1kg 的样品量即会导致NaClO 溶液的ORP 值和有效氯含量骤降,失去杀菌能力;而未切分的油菜对NaClO 溶液的ORP值影响较弱,质量达9kg 时,NaClO 溶液的ORP值仍有约600mV;蔬菜汁液对NaClO溶液的ORP 影响呈反“S”曲线,依据Boltzman 拟合方程以及拐点理论,NaClO 溶液ORP 值降到600mV 时,溶液已基本失去杀菌能力,需补充新鲜杀菌剂。 相似文献
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目的:为控制德尔卑沙门氏菌(Salmonella Derby)在食品加工过程中的污染,研究不同体积分数次氯酸钠对S. Derby生物被膜的抑制作用及其机制。方法:采用结晶紫染色法和平板菌落计数法观察次氯酸钠对生物被膜的抑制和清除效果,进一步观察不同体积分数次氯酸钠作用下沙门氏菌泳动能力和生物被膜内细胞的代谢活性、胞外聚合物含量和微观形态的变化规律。结果:次氯酸钠的最小抑菌浓度(minimum inhibitory concentration,MIC)为0.08%(体积分数,下同),亚MIC(0.04%、0.02%、0.01%)的次氯酸钠可以抑制S. Derby生物被膜的形成,对成熟生物被膜也有一定的清除效果,且不同亚MIC次氯酸钠的作用效果差异显著(P<0.05);不同体积分数次氯酸钠处理能降低生物被膜内细胞代谢活性,抑制胞外多糖的合成,且不同体积分数次氯酸钠的作用效果差异显著(P<0.05)。激光共聚焦扫描显微镜结果显示,与对照组相比,次氯酸钠处理使得生物被膜厚度减小、活菌数减少、死菌数增多、细菌由聚集状态变为分散状态。结论:不同体积分数次氯酸钠对S. Derby生物被膜的形成有明显的抑制作用,这一作用与干扰细菌生长、生物被膜内细胞代谢活性和胞外多糖的合成有关。 相似文献
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为探究不同条件下次氯酸钠消毒处理后对产生氨基脲残留的影响,以鸡爪为研究对象,考察次氯酸钠浓度、温度、浸泡时间、pH值等因素的影响。样品经次氯酸钠溶液处理后,在酸性条件下采用2-硝基苯甲醛进行衍生,调节pH值至中性后用乙酸乙酯提取,液相色谱-串联质谱仪进行测定,同位素内标法定量。结果表明,有效氯质量浓度、温度及浸泡时间与氨基脲产生量呈明显的正相关性;在pH 9~12范围内,鸡爪中氨基脲产生量随着浸泡溶液pH值的升高而增大。消毒处理过的样品经水漂洗后氨基脲含量减少50%~60%。 相似文献
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对次氯酸钠与过硫酸钾分别作为氧化剂生产氧化淀粉进行了比较研究.结果表明,在制备 粉状氧化淀粉时用次氯酸钠作氧化剂的效果比过硫酸钾好,且次氯酸钠以滴加方式加入淀粉中效 果更好. 相似文献
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为降低鸡胸肉减菌过程中次氯酸钠的使用浓度,本研究采用了超声(300W、工作1s、停歇1s、总时间15 min)与次氯酸钠(30 mg/L)相结合的方式对鸡胸肉进行处理。通过对鸡胸肉冷藏(4 ℃)过程中菌落总数、pH值、色泽、嫩度、质构特性、保水性指标的测定,探讨了超声协同次氯酸钠(U/SH30处理)对鸡胸肉的减菌效果及冷藏过程中品质的影响。结果表明:与对照组(浸没在4 ℃预冷的90 mL无菌生理盐水中15 min的样品)相比,在冷藏第0天时,U/SH30处理对鸡胸肉的pH值、色泽、质构特性无显著影响(P>0.05),菌落总数显著下降(P<0.05),嫩度和保水性显著增大(P<0.05);在冷藏1~6 d,菌落总数、pH值、b*值、硬度和黏性显著低于对照组(P<0.05),弹性、L*值、a*值整体上显著高于对照组(P<0.05)。因此,超声协同次氯酸钠处理可以提高鸡胸肉的嫩度和保水性,并延长其保鲜期。 相似文献
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The time course for hydrolysis of starch with α-amylase and oxidation of starch with Na-hypochlorite was studied with the aid of gel chromatography. It was found that the initial steps in the hydrolysis can be described as a consecutive reaction in which the fractions Mw > 5 · 105, 5 · 105 > Mw > 1 · 105 and Mw < 1 · 105 are contained. The reaction in the course of decomposition with α-amylase is one of the first order, while decomposition by means of hypochlorite is a second order reaction. There are considerable differences in the changes in molecular weight distribution between the two methods. Hydrolysis with α-amylase gives a solution with a symmetrical molecular weight distribution whereas hypochlorite oxidation obviously causes splitting of some of the starch molecules, which results in solutions with two molecular weight maxima. 相似文献
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αs-1Casein was polymerized in the presence of sodium hypochlorite (NaOCl). The polymerization was suppressed by succinylation of the protein. Dityrosine and α-aminoadipic acid were detected in the hydrolysate of the reacted proteins. A carbonyl group was detected in the reaction product of acetyl lysine methylester and NaOCl. The Schiff base formation between lysine and a-aminoadipic δ-semialdehyde residues, and dityrosine formation may clarify the mechanism of polymerization. The chemical modification of proteins by NaOCl is expected to be useful for improving the functional properties of food proteins, since polymerization by NaOCl could occur under mild conditions (NaOCl cone, <0.05%; time, <5 min; at 37°C and pH 7-9). 相似文献