1、资料Zeta电位仪测试简化过程Zeta电位仪测试简化过程1、 开启仪器(仪器的开关在设备的后面的右上部位),0Turning on the instrument将出现“嘟嘟”声,指示仪器已开启,开始初始化步骤;如果仪器完成例程,出现第二次“嘟嘟”声。Two further beeps will be heard to indicate the instrument has reached the “default” temperature of 25C.将再次听到两次“嘟嘟”声,说明仪器已达到25C的默认温度。因为本仪器为632.8激光光源,一般需稳定30分钟2、 点击图标,启动Zetasiz
2、er软件3、 点击软件中 File New - Measurement file,创建此次测试文件,一经创建,本次测试的结果均自动保存在此文件中,无需另行保存。4、 制备样品5、 将江 制备的样品注入样品池,粒径分布需1.0 ml1.5 ml,Zeta点位测量至少需要1.0 ml。6、 0将样品池插入仪器中,等待温度平衡点击Start (),0即进行测量。8、 使用光盘拷取数据。使用注意事项测量粒径分布1. 测量粒径前,需查知样品分散剂的粘度、折光指数(Refractive Index)2. 用卷纸轻轻点拭样品池外侧水滴,切勿用力擦拭,以防将样品池划伤,如发现样品池有划纹,需更换。3. 手尽量
3、避免触摸样品池下端,否则会影响光路。4. 一定要去除样品池内的气泡5. 实验室提供的样品池为聚苯乙烯材质,不可用于测量有机分散体系6. 实验室提供的样品池,测量温度不可高于50摄氏度7. 如需测量有机分散体系或高于50摄氏度,请自带石英比色皿8. 使用滤纸过滤时,舍去过滤后的第一滴样品,以防滤纸上杂质进入样品池测量时需自带:卷纸、多个注射器、多个离心管(用于稀释样品)Zeta电位测量1、 测量粒径前,需查知样品分散剂的粘度、折光指数(Refractive Index)、介电常数(Dielectric constant)2、 用卷纸轻轻点拭样品池外侧水滴,尤其是两个塞子外侧3、 一定要去除样品池
4、内的气泡,尤其是电极上气泡4、 如发现电极变黑,需更换5、 实验室提供的样品池为聚苯乙烯材质,不可用于测量有机分散体系6、 实验室提供的样品池测量温度不可高于70度7、 使用滤纸过滤时,舍去过滤后的第一滴样品,以防滤纸上杂质进入样品池测量时需自带:卷纸、多个注射器(5ml)、多个离心管(用于稀释样品)使用使用光盘 0 制备样品 粒径Sample concentration样品浓度Each type of sample material has its own ideal range of sample concentration for optimal measurements.每个类型的样品
5、材料,有最佳的样品浓度测量范围。If the sample concentration is too low, there may not be enough light scattered to make a measurement.如果样品浓度太低,可能会没有足够的散射光进行测量。This is unlikely to occur with the Zetasizer except in extreme circumstances.除极端情况外,对该仪器来说一般不会发生。If the sample is too concentrated, then light scattered by o
6、ne particle will itself be scattered by another (this is known as multiple scattering).如果样品太浓,那么一个粒子散射光也会被其它粒离所散射(这称为多重散射)。The upper limit of the concentration is also governed by the point at which the concentration no longer allows the sample to freely diffuse, due to particle interactions.浓度的上限也要
7、考虑到:在某一浓度以上,由于粒子间相互作用,粒子不再进行自由扩散。0Particle size粒径Min. Concentration (Recommended)最小浓度(推荐)Max. Concentration (Recommended)最大浓度(推荐) 10nm 10nm0.5g/l0.5g/lOnly limited by the sample material interaction, aggregation, gelation etc.仅由样品材料相互作用、聚集、胶凝作用等限制10nm to 100nm10nm to 100nm0.1mg/l0.1mg/l5% mass (assu
8、ming a density of 1g/cm3)5%质量(假定密度1g/cm3)100nm to 1m100nm to 1m0.01g/l0.01g/l(10-3%质量)01%质量(假定密度1g/cm3) 1m 1m0.1g/l0.1g/l(10-2%质量)(10-2 % mass) 1% mass (assuming a density of 1g/cm3)1%质量(假定密度1g/cm3)Considerations for small particles小粒子需要考虑的事项Minimum concentration最小浓度For particle sizes smaller than 1
9、0nm, the major factor in determining a minimum concentration is the amount of scattered light that the sample generates.对小于10nm的粒子,决定最小浓度的主要因素是样品生成的散射光强。In practice, the concentration should generate a minimum count rate of 10,000 counts per second (10kcps) in excess of the scattering from the dispe
10、rsant.实用的角度,这种浓度应生成最低光强为10,000cp/s(10 kcps),这样才能超过分散剂的散射。As a guide, the scattering from water should give a count rate in excess of 10kcps, and toluene in excess of 100kcps.作为一个指导,水的散射光强应超过10kcp的,甲苯的应超过100kcps。Maximum concentration最大浓度For samples with small particle sizes, a maximum concentration d
11、oes not really exist (in terms of performing Dynamic Light Scattering (DLS) measurements).对小粒径的样品,最大浓度实际上不存在(以进行动态光散射(DLS)测量的术语来说)。However, in practice, the properties of the sample itself will set the maximum value.但实际,样品的性质本身会决定此最大值。For example, the sample may have the following properties:例如,样品可能
12、有以下性质:Gelation.胶凝作用:A gel is unsuitable for measurement using the Zetasizer (this is true for all instruments based on Dynamic Light Scattering).凝胶不适合采用Zetasizer进行测量(这对所有基于动态光散射原理仪器都是事实)Particle interactions.粒子相互作用:If there are interactions between the particles then the diffusion constant of the pa
13、rticles usually changes, leading to incorrect results.如果粒子之间存在相互作用,那么粒子的扩散常数通常会改变,导致不正确的结果。A concentration should be chosen to avoid particle interactions.应选择某一浓度避免粒子相互作用。Considerations for large particles大颗粒需要考虑的事项Minimum concentration最小浓度Even for larger particles, the minimum concentration is effe
14、ctively still a function of the amount of scattered light, though the additional effect of “number-fluctuation” must be taken into account.即使对大颗粒,知道最小浓度仍然是得到有效散射光强的保障,虽然我们还必须考虑“Number fluctuation”(数量 波动: 粒子浓度太低导致在光路中的粒子数量随时间较大波动)的附加效应。As an example, if a sample of large particles (say 500nm) were to be measured at low concentration (say 0.001 g/l (10-4%), the amount of scattered light generated would be more than sufficient
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