氢氧化铁胶体制备及电泳

氢氧化铁胶体制备及电泳 设计性实验 Fe(OH)胶体的制备和电泳 3 韩丰 郭麟 刘天乙 (大连大学 环境与化学工程学院 化学111，辽宁大连 116622) 指导老师:李艳华 贾颖萍 [摘 要] 文章主要探究氢氧化铁的制备、纯化温度及时间对胶体的影响，并测定的胶体性质，最终确定利用化学法制备，纯化温度介于60?到70?，时间控制在2周左右，辅助液选用KCl溶液并且电导率与胶体相同，电泳电压为60V，得到Fe(OH)胶体的ζ 电位为;并3 且研究了相同阳离子不同价态阴离子的盐对于胶体聚沉的影响，并得到价态越高，聚沉能力越强。 [关 键 词] Fe(OH)胶体;电泳;ζ 电位;实验;聚沉值 3 [1,2]作为物理化学实验中经典实验---胶体的制备及采用电泳方法测定溶胶的电动电势ζ，我们很有必要去认识和学习。但由于溶胶的电泳受诸多因素如:溶胶中胶粒形状、表面电荷数量、辅助液中电解质的种类、温度和所加电压等。根据实验内容主要利用水解Fe(OH)3溶液制备的氢氧化铁胶体，并且通过渗析纯化后使用。另外，根据教材的实验步骤进行电泳实验，经常遇到溶胶与辅助液间有一界模糊和两极间界面移动距离相差较大等问题。为了使这些问题能够得以很好的解决，我们主要是氢氧化铁胶体的制备、Fe(OH)胶体的纯化时渗3析温度及时间的控制、辅助液的选择与其电导率控制、胶体溶液和导电液的正确加入以及适度的电泳电压等方面对这一实验进行了改进研究来探究Fe(OH)胶体的ζ 电位，通过与理论3 值相比较，做出合理的误差分析，以此来对胶体电泳最佳实验条件得以确定，以这一实验改进的条件探讨及结果。 1、实验部分 1.1 实验原理 1.1.1 胶体简介 溶胶是一个多相系统;是热力学不稳定系统(要依靠稳定剂使其形成离子或分子吸附层， [3]才能得到暂时的稳定)，胶粒(分散相)大小在1~100nm之间 ; 1.1.2制备胶体的原理: 凝胶作用:由于溶剂的作用，使沉淀重新溶解成胶体溶液。 化学凝聚法:通过化学反应使生成物呈过饱和状态，然后粒子再胶合成胶粒。 1.1.3 氢氧化铁溶胶ζ电势的测定计算 实验主要是通过测定一定外加电场强度下胶粒的电泳速度的方法计算胶粒的ζ 电位。采用界面移动法测胶粒的电泳速率。 在电泳仪的两段极施加电位差E后，在时间t内，如溶胶界面移动的距离为d，则胶粒的电泳速率: dv, t appearance of the weld appearance quality technical requirements of the project must not have a molten metal stream does not me1 lt the base metal to weld, weld seam and heat-affected zone surface must not have cracks, pores, defects such as crater and ash, surface smoothing, weld and base metal should be evenly smooth transition. Width 2-3 mm from the edge of weld Groove. Surface reinforcement should be less than or equal to 1 + 0.2 times the slope edge width, and should not be greater than 4 mm. Depth of undercut should be less than or equal to 0.5 mm, total length of the welds on both sides undercut not exceed 10% of the weld length, and long continuous should not be greater than 100 mm. Wrong side should be less than or at 0.2T, and should not be greater than 2 mm (wall thickness mm t) incomplete or not allow 7.5 7.5.1 installation quality process standards of the electrical enclosure Cabinet surface is clean, neat, no significant phenomenon of convex, close to nature, close the door. 7.5.2 Cabinet Cabinet face paints no paint, returned to rusted, consistent color. 7.5.3 uniform indirect gap from top to bottom, slot width <1.5mm 7.5.4 adjacent Cabinet surface roughness is 0. 7.5.5 the cabinets firmly fixed, crafts beautiful. 7.5.6 Cabinet surface gauge, switch cabinet mark clear, neat, firm paste. 7.5.7 Terminal row of neat, is reliable, the appearance is clean and not damaged. 7.5.8 cables neat and clean, solid binding, binding process in appearance. 7.5.9 the first cable production firm, crafts beautiful, clear signage does not fade. 7.5.10 fireproof plugging tight, no cracks and pores. 7.6 7.6.1 of the standard electrical wiring quality technology cable a, the multi-core wire bunch arrangement should be parallel to each other, horizontal wire harness or wire should be perpendicular to the longitudinal multi-core wire bunch. The distance between the wire harness and wire harness symmetry, and as close as possible. B-core wiring harness into round, multi-core wire bunch used g wire binding, fastening 若电极极板经过液体通道的长度为l，则在两极间液体的电导率相同时，电极间的场强 E为: H,l 胶粒表面的ζ电位可按下式求得: ,,k,; ,v,H 1022-1-11022-1-1k是与胶体形状有关的常数(球型的是5.4*10VsKgm，棒型的是3.6*10VsKgm)本实验中氢氧化铁是棒型。是氢氧化铁的介质的粘度(Pa?s);是介质的相对介电常数,, -3[1](ln=4.474266-4.54426*10T) , 1.2 药品和仪器 DDSJ-308A型电导率仪(上海精密科学仪器有限公司)，DYY-2C型电泳仪及U型电泳槽一套(北京市六一仪器厂)，半透膜(美国进口)，MP-13H恒温水浴仪。 三氯化铁(99.0%)(AR，天津市大茂化学试剂厂)，氯化钾(99.5%)(AR，天津市大茂化学试剂厂)，硝酸银(99.8%)(AR，中国医药(集团)上海化学试剂公司)， 氢氧化钠(96.0%)(AR，天津市秘密欧化学试剂有限公司)，硫酸钾(99.0%)(AR，天津市大茂化学试剂厂)，铁氰酸钾(99.5%)(AR，天津市化学试剂一厂)，氯化钠(99.5%)(AR，哈 ，尔滨永丰化工厂)，硝酸钾(99.0%)(天津市大茂化学试剂厂)，硫氰酸钾(97.18%)(AR浙江省温州市化学用料厂) [1]1.3 胶体的制备 1.3.1化学法制备 250ml烧杯中放100ml蒸馏水，加热至沸腾，向其里面滴加5ml 10% FeCl3溶液，并不 [4]断搅拌，加入完毕后持续煮沸几分钟，水解后形成氢氧化铁胶体，其结构式为 : +-x+-{[m Fe(OH)?nFeO?(n-x)Cl]}?xCl 3 1.3.2溶胶法制备 取1ml 50%的FeCl 溶液在小烧杯中，加水稀释到10ml 逐渐加入NaOH 到稍微过量，3 过滤，用水洗涤数次，在将沉淀放到另一个烧杯里，加水20ml，再加入20%的FeCl约1ml 3用玻璃棒搅拌，加热，沉淀消失，形成透明的胶体溶液。 1.4 胶体的渗析纯化 (1)把制好的胶体放置到半透膜袋里，用线绑住口，分为两份，一份放在到400ml蒸馏水渗析，并保持温度在60~70?，另一份放在400ml蒸馏水中室温，每半小时换一次水，并检 -3+- 3+验水中是否含有Cl和Fe，直至没有Cl和Fe，即加入AgNO无明显沉淀。并记录2个3 烧杯无明显沉淀所需时间。实验结束后，将胶体置于去离子水中继续渗析，保持每天换水。 -3 (2)电极常数的标定(25? 0.01mol/dmKCl的电导率为1408.3uS/cm) 3-1测其电导率(应在0.6*10us?cm以下)，如若超过此值继续渗析。 et face paints no paint, returned to rusted, consistent color. 7.5.3 uniform indirect gap from top to bottom, slot width <1.5ure Cabinet surface is clean, neat, no significant phenomenon of convex, close to nature, close the door. 7.5.2 Cabinet Cabinenclosr than 2 mm (wall thickness mm t) incomplete or not allow 7.5 7.5.1 installation quality process standards of the electrical h, and long continuous should not be greater than 100 mm. Wrong side should be less than or at 0.2T, and should not be greatelengtundercut should be less than or equal to 0.5 mm, total length of the welds on both sides undercut not exceed 10% of the weld nforcement should be less than or equal to 1 + 0.2 times the slope edge width, and should not be greater than 4 mm. Depth of3 mm from the edge of weld Groove. Surface rei-uld be evenly smooth transition. Width 2affected zone surface must not have cracks, pores, defects such as crater and ash, surface smoothing, weld and base metal sho-he base metal to weld, weld seam and heatmelt tappearance of the weld appearance quality technical requirements of the project must not have a molten metal stream does not core wire bunch used g wire binding, fastening-core wiring harness into round, multi-etry, and as close as possible. Bcore wire bunch. The distance between the wire harness and wire harness symm-longitudinal multicore wire bunch arrangement should be parallel to each other, horizontal wire harness or wire should be perpendicular to the -ality technology cable a, the multig quclear signage does not fade. 7.5.10 fireproof plugging tight, no cracks and pores. 7.6 7.6.1 of the standard electrical wirin cables neat and clean, solid binding, binding process in appearance. 7.5.9 the first cable production firm, crafts beautiful, 7.5.8 witch cabinet mark clear, neat, firm paste. 7.5.7 Terminal row of neat, is reliable, the appearance is clean and not damaged..4 adjacent Cabinet surface roughness is 0. 7.5.5 the cabinets firmly fixed, crafts beautiful. 7.5.6 Cabinet surface gauge, smm 7.52 1.5胶体性质的测定 1.5.1 观察Tydall现象 用激光笔将光通过胶体溶液，在光束前进方向相垂直的侧面观察，观察是否可以看到一 条光亮的“通路”，如若可以观测，则制备成功，反之需重新制备。 1.5.2 辅助溶液的配置 用NaCl，KCl分别和去离子水，配置和溶胶电导率和温度相同的辅助液。 (1)将Fe(OH)胶体置于恒温水浴中，保持温度在25?左右，将铂黑电极插入胶体中测其3 [5]电导率，并记录 ; (2)用100mL烧杯中取适量去离子水置于恒温水浴中，用胶头滴管取1mol/L KCl溶液或 NaCl溶液，边滴加边搅拌，同时测其电导率，直到电导率与Fe(OH)胶体相同，停止滴加。 31.5.3 电泳速度的测定 (1)用去离子水清洗电泳仪; (2)用少量渗析好的Fe(OH)胶体润洗电泳3 仪2至3次; (3)从U形管两侧的管注入电导率与 Fe(OH)胶体相同的辅助液(KCl溶液)，加3 入的量大概为加入胶体后可没过电极为止; (4)在U形管中间位置用胶头滴管逐滴加入 Fe(OH)胶体，速度控制在1滴/秒; 3 (5)将两铂电极插入支管内并记录电极间距 离(不是水平距离)，并连接电源，开启旋塞 使管内辅助液等高，然后关闭小旋塞，打开 电源，将电压分别调至20V观察胶体界面移 动现象及电极表面现象，记录10min内界面 移动的距离，共记录30min，若在电泳开始 时有轻微模糊或者由于电泳仪原因起始读数 不能准确，需等到界面稳定后开始计时; (6)反泳，将正负极对调，重复上述步骤， 记录界面移动距离;记录3次实验值，取其 平均值; (7)在40V、60V、80V、100V电压下再进行上述操作，如若胶体发生聚沉现象，则需重新 注入胶体和缓冲液。 ge, switch cabinet mark clear, neat, firm paste. 7.5.7 Terminal row of neat, is reliable, the appearance is clean and not damm 7.5.4 adjacent Cabinet surface roughness is 0. 7.5.5 the cabinets firmly fixed, crafts beautiful. 7.5.6 Cabinet surface gau<1.5m Cabinet face paints no paint, returned to rusted, consistent color. 7.5.3 uniform indirect gap from top to bottom, slot widthnclosure Cabinet surface is clean, neat, no significant phenomenon of convex, close to nature, close the door. 7.5.2 Cabinet ical ereater than 2 mm (wall thickness mm t) incomplete or not allow 7.5 7.5.1 installation quality process standards of the electrlength, and long continuous should not be greater than 100 mm. Wrong side should be less than or at 0.2T, and should not be gweld th of undercut should be less than or equal to 0.5 mm, total length of the welds on both sides undercut not exceed 10% of thee reinforcement should be less than or equal to 1 + 0.2 times the slope edge width, and should not be greater than 4 mm. Dep3 mm from the edge of weld Groove. Surfac-uld be evenly smooth transition. Width 2affected zone surface must not have cracks, pores, defects such as crater and ash, surface smoothing, weld and base metal sho-elt the base metal to weld, weld seam and heatmappearance of the weld appearance quality technical requirements of the project must not have a molten metal stream does not core wire bunch used g wire binding, fastening-core wiring harness into round, multi-symmetry, and as close as possible. B core wire bunch. The distance between the wire harness and wire harness-longitudinal multicore wire bunch arrangement should be parallel to each other, horizontal wire harness or wire should be perpendicular to the -ng quality technology cable a, the multil wiritiful, clear signage does not fade. 7.5.10 fireproof plugging tight, no cracks and pores. 7.6 7.6.1 of the standard electrica7.5.8 cables neat and clean, solid binding, binding process in appearance. 7.5.9 the first cable production firm, crafts beauaged. 3 1.6 聚沉值的测定 用移液管在7个干净的锥形瓶各注入1ml的氢氧化铁胶体，然后加入不同浓度梯度的KCl 、KSO和KFe(CN) ，在开始有明显的聚沉物出现时，停止加入，记录所用的电解2436 [7]质的体积 。 2、结果与讨论 2.1 两种方法制备胶体对实验的影响 表1 化学法和溶胶法制备胶体的比较 方法 化学法 溶胶法 条件 加热 常温 所需药品 10% FeCl 20%FeCl，NaOH 33 Tydall现象 明显 不明显 由表1可知两种方法，化学法较好，原因是与溶胶法相比较所需药品少，并且，溶胶法生成沉淀，需要洗涤沉淀数次才可将碱洗净，然后才可制备出胶体。 2.2 胶体渗析温度与时间对实验的影响 表2 温度对胶体纯化的影响 温度 60~70? 室温 用硝酸银检测无沉淀所需时间 短 长 表3 时间对胶体电导率的影响 时间 3d 7d 11d -1电导率/ us?cm 47.6 21.4 出现聚沉现象 由表2和表3可知提高温度可加快渗析速度，渗析时间越久纯化效果越好，但是时间也不能太久，长时期渗析可以使带正电荷的氢氧化铁溶胶失掉电荷而聚沉。 2.3. 辅助液的选择与其电导率对实验的影响 表4 不同辅助液对实验的影响 辅助液种类 NaCl KCl 实验现象 界面模糊 界面较清晰 表5 不同电导率对实验的影响 与Fe(OH)胶体电导率相同 与Fe(OH)胶体电导率不同 33 界面清晰 界面模糊 由表4和表5可知选择溶液作为KNO辅助液，并且辅助液的电导率与Fe(OH)胶体相同33 +8 2-1-1-8 2-1-1最好，其原因是因为K (7.62*10m?V?s)与Cl(7.91*10m?V?s)的离子迁移数率[3]相差不大，所以作为辅助液最好。 longitudinal multicore wire bunch arrangement should be parallel to each other, horizontal wire harness or wire should be perpendicular to the -ality technology cable a, the multig quclear signage does not fade. 7.5.10 fireproof plugging tight, no cracks and pores. 7.6 7.6.1 of the standard electrical wirin cables neat and clean, solid binding, binding process in appearance. 7.5.9 the first cable production firm, crafts beautiful, 7.5.8 witch cabinet mark clear, neat, firm paste. 7.5.7 Terminal row of neat, is reliable, the appearance is clean and not damaged..4 adjacent Cabinet surface roughness is 0. 7.5.5 the cabinets firmly fixed, crafts beautiful. 7.5.6 Cabinet surface gauge, smm 7.5et face paints no paint, returned to rusted, consistent color. 7.5.3 uniform indirect gap from top to bottom, slot width <1.5ure Cabinet surface is clean, neat, no significant phenomenon of convex, close to nature, close the door. 7.5.2 Cabinet Cabinenclosr than 2 mm (wall thickness mm t) incomplete or not allow 7.5 7.5.1 installation quality process standards of the electrical h, and long continuous should not be greater than 100 mm. Wrong side should be less than or at 0.2T, and should not be greatelengtundercut should be less than or equal to 0.5 mm, total length of the welds on both sides undercut not exceed 10% of the weld nforcement should be less than or equal to 1 + 0.2 times the slope edge width, and should not be greater than 4 mm. Depth of3 mm from the edge of weld Groove. Surface rei-uld be evenly smooth transition. Width 2affected zone surface must not have cracks, pores, defects such as crater and ash, surface smoothing, weld and base metal sho-he base metal to weld, weld seam and heatmelt tappearance of the weld appearance quality technical requirements of the project must not have a molten metal stream does not core wire bunch used g wire binding, fastening-core wiring harness into round, multi-etry, and as close as possible. Bcore wire bunch. The distance between the wire harness and wire harness symm-4 2.4电泳电压对实验的影响 表6不同时间内的移动距离 测定时间 10min/cm 20min/cm 30min/cm 电压/V 20 0.3 0.7 1.2 40 0.5 1.0 1.6 60 1.1 2.0 2.7 80 1.4 2.5 3.2 100 1.6 2.9 4.3 *实验条件:温度:18.5?，大气压:100.72KPa;表中每个电压下都是测量三次取平均值 表7 不同电压下胶体的电泳速度 -1-1E/V L/cm d/cm v/m*s H/V*m ζ/mV 电泳界面 -720 22.5 1.2 6.6667*10 88.89 56.48 模糊 -740 24.1 1.6 8.8889*10 165.98 40.33 较清晰 -660 24.6 2.7 1.5000*10 243.90 46.32 清晰 -680 24.2 3.2 1.7778*10 330.58 40.50 较清晰，有少量聚沉 -6100 22.6 4.3 2.3889*10 442.48 40.33 聚沉现象明显 *实验条件:温度:18.5?，大气压:100.72KPa 实验时间均为30min(1800s);是8.065F/m;,, -3 [5]是1.0559*10Pa?s ; 60 55实验值50理论值ζ电势/mV45 40 35 30 25 20电压/V20406080100 图2.不同电压下的ζ电势与理论值比较 由表6、表7和图1，可知，在温度为18.5?、100.72KPa下，电压选用60V测定ζ电 位与理论值最接近，根据公式可知E越大，电泳速率越大，电压太小会导致电泳速率较慢， 界面也不清晰平整，所以与理论值有差距;反之电压过大，阴极产生气体速率会加快，电流 热效应增大，并且胶体的发散、凝胶作用增强，发生聚沉现象，电泳速率和实验效果并不理 [6]想。本文认为电压适宜在60V左右，现象明显且接近理论值 。 nclosure Cabinet surface is clean, neat, no significant phenomenon of convex, close to nature, close the door. 7.5.2 Cabinet ical ereater than 2 mm (wall thickness mm t) incomplete or not allow 7.5 7.5.1 installation quality process standards of the electrlength, and long continuous should not be greater than 100 mm. Wrong side should be less than or at 0.2T, and should not be gweld th of undercut should be less than or equal to 0.5 mm, total length of the welds on both sides undercut not exceed 10% of thee reinforcement should be less than or equal to 1 + 0.2 times the slope edge width, and should not be greater than 4 mm. Dep3 mm from the edge of weld Groove. Surfac-uld be evenly smooth transition. Width 2affected zone surface must not have cracks, pores, defects such as crater and ash, surface smoothing, weld and base metal sho-elt the base metal to weld, weld seam and heatmappearance of the weld appearance quality technical requirements of the project must not have a molten metal stream does not core wire bunch used g wire binding, fastening-core wiring harness into round, multi-symmetry, and as close as possible. B core wire bunch. The distance between the wire harness and wire harness-longitudinal multicore wire bunch arrangement should be parallel to each other, horizontal wire harness or wire should be perpendicular to the -ng quality technology cable a, the multil wiritiful, clear signage does not fade. 7.5.10 fireproof plugging tight, no cracks and pores. 7.6 7.6.1 of the standard electrica7.5.8 cables neat and clean, solid binding, binding process in appearance. 7.5.9 the first cable production firm, crafts beauaged. ge, switch cabinet mark clear, neat, firm paste. 7.5.7 Terminal row of neat, is reliable, the appearance is clean and not damm 7.5.4 adjacent Cabinet surface roughness is 0. 7.5.5 the cabinets firmly fixed, crafts beautiful. 7.5.6 Cabinet surface gau<1.5m Cabinet face paints no paint, returned to rusted, consistent color. 7.5.3 uniform indirect gap from top to bottom, slot width5 2.5 不同价态离子对Fe(OH)胶体的聚沉值 3 表8 不同价态离子的聚沉值 编号 1 2 3 4 5 6 7 KCl 有 有 无 KSO 有 有 有 有 无 24 KFe(CN) 有 有 有 有 有 有 无 36 3*其中编号1为1mol/dm，10ml;编号2为从1中去1ml，稀释至10ml;以此稀释至编号7。有表示有沉淀，无为没有沉淀。 根据表7可知KFe(CN)的聚沉所需浓度最小，即聚沉能力最大，KSO次之，最小为KCl，3624 由于时间原因，并没有准确的测定聚沉临界浓度，理论上可以根据Schulze-Hardy(舒尔茨 [4]-哈代)规则，聚沉值与胶粒电性相反的异电性离子价数的六次方成反比。简而言之，就是异电性离子的价数愈高，聚沉能力愈大。 3、结论 通过本次实验，确定了利用化学法制备胶体，即将FeCl 溶液滴加至沸水中，并不断搅3 拌，且保持持续沸腾;然后在温度为60到70?渗析纯化，时间控制在1周左右;选用KCl溶液作为辅助液，并且要求电导率与胶体电导率相同;电压控制在60V左右，进行Fe(OH)3胶体的电泳实验，效果最好;并且异电性离子的价数愈高，聚沉能力愈大。 4、个人体会 韩丰:没有了无机化学实验的缤纷多彩，没有了分析实验复杂数据，没有了有机实验的气味“芬芳”，这次的物理化学设计型实验终于在规定时间内愉快完成。俗话说，纸上得来终觉浅，绝知此事要躬行。相比以前课堂上短暂的照本宣科的实验，这次实验完全是在自己搜索资料、配置药品、调试仪器的情况下完成的，所收获相比以前的实验多的不是一星半点。通过收集资料，查阅书籍，我了解到对于一个实验，每个不住都是关键，一不注意的搅拌不充分，胶体可能就制备不成功;滴加速度过快，电泳时界面就有可能模糊。电压等其他条件都对实验有着很大的影响，随便改变其中的一个，都会有着不同的效果，当了解到这些的时候，我深深的觉得这个实验并不是和题目中那样仅仅是制备和电泳那么简单，需要的是全心全意的去思考某些东西，才可以完成此次试验，比如电极常数的标定，需要配置标准溶液等很多方面; 这次实验真是让我体会到“欲速则不达”，刚开始的渗析，因为着急去做电泳，所以渗析时间很短，仅仅是测定了氯离子的浓度，然后好几次都是因为胶体纯化的不好，在电泳期间，发生了聚沉现象。所以，实验是严谨的，不能因为想快点做出东西而忽略实验过程的必要性。还有在装电泳管时，也是因为心急，在向管内滴加胶体时，滴加速度过快，导致胶体 cables neat and clean, solid binding, binding process in appearance. 7.5.9 the first cable production firm, crafts beautiful, 7.5.8 witch cabinet mark clear, neat, firm paste. 7.5.7 Terminal row of neat, is reliable, the appearance is clean and not damaged..4 adjacent Cabinet surface roughness is 0. 7.5.5 the cabinets firmly fixed, crafts beautiful. 7.5.6 Cabinet surface gauge, smm 7.5et face paints no paint, returned to rusted, consistent color. 7.5.3 uniform indirect gap from top to bottom, slot width <1.5ure Cabinet surface is clean, neat, no significant phenomenon of convex, close to nature, close the door. 7.5.2 Cabinet Cabinenclosr than 2 mm (wall thickness mm t) incomplete or not allow 7.5 7.5.1 installation quality process standards of the electrical h, and long continuous should not be greater than 100 mm. Wrong side should be less than or at 0.2T, and should not be greatelengtundercut should be less than or equal to 0.5 mm, total length of the welds on both sides undercut not exceed 10% of the weld nforcement should be less than or equal to 1 + 0.2 times the slope edge width, and should not be greater than 4 mm. Depth of3 mm from the edge of weld Groove. Surface rei-uld be evenly smooth transition. Width 2affected zone surface must not have cracks, pores, defects such as crater and ash, surface smoothing, weld and base metal sho-he base metal to weld, weld seam and heatmelt tappearance of the weld appearance quality technical requirements of the project must not have a molten metal stream does not core wire bunch used g wire binding, fastening-core wiring harness into round, multi-etry, and as close as possible. Bcore wire bunch. The distance between the wire harness and wire harness symm-longitudinal multicore wire bunch arrangement should be parallel to each other, horizontal wire harness or wire should be perpendicular to the -ality technology cable a, the multig quclear signage does not fade. 7.5.10 fireproof plugging tight, no cracks and pores. 7.6 7.6.1 of the standard electrical wirin6 扩散，界面很模糊，然后又是重新装管，所需的时间并不比一次性认真装管所需的时间少，让我明白实验一定得仔细严谨。 在实验中，有实验失败时的沮丧，也有实验成功的喜悦，这对于我来说是一次很深的记忆，以后还要做毕业论文，这次实验，无疑是一次宝贵的经验。还有这次实验由于时间的原因，每次方法都做了很少的次数，而得到的数据肯定不是很准确，所以假如以后可以从事科学研究，一定不能这样，必须保持严谨的态度，才能确保实验的准确性。 最后，实验能够顺利完成，离不开李老师、贾老师和白老师的指导和同伴的共同努力，在此对于他们的帮助表示由衷感谢。 郭麟:这是我第三次做创新实验了，从第一次的甲基橙得制备到第二次的可见光下对硝基苯还原反应的研究，到这一次胶体的制备和电泳。我觉得我真是有了一个很大的进步。创新实验是自己设计然后自己进行的实验，在之前有老师指点的情况下，我都不能十分顺利的完成实验，现在没有老师的指导实验更是遇到了很多的困难，这就反映出了我的问题和不足，不够耐心不够仔细，对问题的考虑没有前瞻性，不过我还学到了更重要的事情，那就是团队合作，我们三个人互相帮助，互相提出问题并且解决，让我觉得团队是成功不可缺少的重要部分。胶体的制备让我温故知新，用到了丁达尔现象等等以前就学过的知道，学以致用，也让我有些许成就感。这次的实验对我以后的毕业论文有指导性的意义，我会将我这次所学用到以后的学习中，继续努力～ 刘天乙:至今，我已经完成了三次创新实验，从第一次的独立研究实验方案，到第二次开始尝试与他人共同探讨，再到现在与组员一同完成实验，我从学习中得到了成长。实验中，在进行胶体的制备，我纠正了对丁达尔现象的一些误解，明确了其是光的散射，并非光的穿透。电泳时，对电压的选取，也颇为头痛，聚沉已经屡见不鲜了。还有在测聚沉值时，为偷懒而导致一次测量的失败等等。从大一时，老师手把手实验，到现在与组员一同完成实验，这些便是我最大的收获。 参考文献 [1]孟长功，辛剑(基础化学实验,M,(高等教育出版社，2009(156-158 [2]复旦大学.物理化学实验(第二版)[M].北京:高等教育版社.1993:166,171. [3]孙世刚，王野，陈良坦，等.物理化学(第二版)[M].厦门大学出版社:2008:268 [4]傅献彩，沈文霞，姚天扬，等.物理化学(第五版)[M].高等教育出版社，2006:439-440 [5] 谢祖芳，陈希慧，晏全. 对氢氧化铁溶胶电泳实验改进的研究[J]. 玉林师范学院学报-自然科学,2001年，22(3);83-84 [6] 李显峰.Fe(OH)胶体电泳实验影响因素探讨[J].广东化工，2012年，39(3):76 3 [7] 钱亚兵,袁红霞,鲍正荣.Fe(OH)3胶体电泳实验再探索[J].化学 教学,2002,12:9,10. Cabinet face paints no paint, returned to rusted, consistent color. 7.5.3 uniform indirect gap from top to bottom, slot widthnclosure Cabinet surface is clean, neat, no significant phenomenon of convex, close to nature, close the door. 7.5.2 Cabinet ical ereater than 2 mm (wall thickness mm t) incomplete or not allow 7.5 7.5.1 installation quality process standards of the electrlength, and long continuous should not be greater than 100 mm. Wrong side should be less than or at 0.2T, and should not be gweld th of undercut should be less than or equal to 0.5 mm, total length of the welds on both sides undercut not exceed 10% of thee reinforcement should be less than or equal to 1 + 0.2 times the slope edge width, and should not be greater than 4 mm. Dep3 mm from the edge of weld Groove. Surfac-uld be evenly smooth transition. Width 2affected zone surface must not have cracks, pores, defects such as crater and ash, surface smoothing, weld and base metal sho-elt the base metal to weld, weld seam and heatmappearance of the weld appearance quality technical requirements of the project must not have a molten metal stream does not core wire bunch used g wire binding, fastening-core wiring harness into round, multi-symmetry, and as close as possible. B core wire bunch. The distance between the wire harness and wire harness-longitudinal multicore wire bunch arrangement should be parallel to each other, horizontal wire harness or wire should be perpendicular to the -ng quality technology cable a, the multil wiritiful, clear signage does not fade. 7.5.10 fireproof plugging tight, no cracks and pores. 7.6 7.6.1 of the standard electrica7.5.8 cables neat and clean, solid binding, binding process in appearance. 7.5.9 the first cable production firm, crafts beauaged. ge, switch cabinet mark clear, neat, firm paste. 7.5.7 Terminal row of neat, is reliable, the appearance is clean and not damm 7.5.4 adjacent Cabinet surface roughness is 0. 7.5.5 the cabinets firmly fixed, crafts beautiful. 7.5.6 Cabinet surface gau<1.5m7