资料Zeta电位仪测试简化过程.docx

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

15、 be measured at low concentration (say 0.001 g/l (10-4%), the amount of scattered light generated would be more than sufficient to perform a measurement.例如，如果在低浓度（比如说0.001 g/l （10-4%）下测量一个大颗粒（比如说500nm）样品，生成的散射光大于进行测量的所需量。However, the number of particles in the scattering volume is so small (fewer th

16、an 10) that severe fluctuations of the momentary number of particles in the scattering volume will occur.但是，散射体积中粒子数太小（小于10），在散射体积中会发生严重的粒子数量随时间波动。These fluctuations are not the type assumed by the calculation method used, or will generally be misinterpreted as larger particles within the sample.这些波

17、动与所用计算方法中假设的类型不符，通常会被错误诠释为样品中的大颗粒。Such fluctuations must be avoided and this determines the lower limit for the required concentration and for a lower limit in the number of particles.必须避免此类波动，这决定了所要求浓度的下限和粒子数的下限。At least 500 particles should be present, however, a minimum of 1000 particles is recom

18、mended.至少应存在500个粒子，但推荐最小量为1000个粒子。See the figure below for an estimate plot of the number of particles per scattering volume for different concentrations assuming a density of 1 g/cm.参见下图：对假定密度为1 g/cm的不同浓度溶液中，每散射体积中粒子数的估算图。Maximum concentration最大浓度The upper limit for the sample concentration for lar

19、ger particles is determined by their tendency to cause multiple-scattering.较大颗粒的样品浓度上限，由其引起多重散射的趋势决定。Although the Zetasizer is not very sensitive to multiple-scattering, with increased concentration, the effect of the multiple-scattering becomes more and more dominant, up to a point where so much mu

20、ltiple-scattering is generated that the results of the measurement will be affected.Zetasizer对多重散射不是十分敏感，但随着浓度增加，多重散射效应越来越占优势，在达到某一浓度时，生成过多的多重散射，会影响测量结果。Of course, such a high concentration should not be used for accurate measurements, and rough estimates are given for maximum concentrations for the

21、 different size classes in the table above.当然，如此高的浓度不应用于精确测量，上表中给出了不同粒径粒子最大浓度的粗略估算。As a general rule, measure at the highest concentration possible before multiple scattering and particle interactions affect the result.通用规则是，在多重散射和粒子相互作用影响结果之前，以可能的最高浓度进行测量 。Dust contamination in the sample can be pr

22、esumed equal for high and low concentrations, and thus, the amount of scattered light from the sample increases in relation to the scattering from the dust contamination as the concentration increases.可以假定样品中的灰尘污染对高浓度和低浓度是相同的，因此样品浓度增加，从样品得到的散射光强相对灰尘散射光强有所增加。Filtration过滤All liquids used to dilute the

23、 sample (dispersants and solvents) should be filtered before use to avoid contaminating the sample.用于稀释样品（分散剂和溶剂）的所有液体，应于使用前过滤，避免污染样品。The size of the filter will be determined by the estimated size of the sample.过滤器的粒径应由样品的估算粒径决定。If the sample is 10nm, then 50nm dust will be an important contaminant

24、 in the dispersant.如果样品是10nm，那么50nm灰尘将是分散剂中的重要污染物。Aqueous dispersants can be filtered down to 0.2m, while non-polar dispersants can be filtered down to 10 or 20nm.水相分散剂可被0.2m孔径膜过滤，而非极性分散剂可被10或20nm孔径膜过滤。Samples are not filtered if at all possible.尽可能不过滤样品。Filters can remove sample by absorption as we

25、ll as physical filtration.过滤膜能通过吸附以及物理过滤消耗样品。Only filter the sample if aware of larger sized particles, such as agglomerates, that need to be removed as they are not of interest, or cause result variations.只有在溶液中有较大粒径粒子如聚集物时，且它们不是所关心的成分，或可能引起结果改变，才过滤样品。Using ultrasonics运用超声波Ultrasonication can be us

26、ed to remove air bubbles or to breakup agglomerates - however, this must be applied carefully in order to avoid damaging the primary particles in the sample.可使用超声处理除去气泡或破坏聚集物 但是，必须谨慎应用，以便避免损坏样品中的原有粒子。Limits for the use of ultrasonication in terms of intensity and application time are strongly sample

27、 dependent.使用超声的强度和施加时间方面，依赖于样品。Minerals such as titanium dioxide are ideal candidates for dispersion by high powered probes, however, the particle size of some materials, such as carbon black, may depend on the power and length of time ultrasonication is applied.矿物质如二氧化钛，是通过超声探头进行分散的一个理想的例子，但是某些矿物质

28、，如炭黑，的粒径，可能依赖于所应用的功率和超声处理时间。Some materials can even be forced to aggregate using ultrasound.某些矿物质粒子聚集。Emulsions and liposomes should not be ultrasonicated.乳状液和脂质体不得采用超声处理。0 制备样品 Zeta电位The optical arrangement for zeta potential measurements in the Zetasizer Nano series means that the concentration re

29、quirements are not as strict as those used for size and molecular weight measurements.Zetasizer Nano中用于Zeta电位测量的光学设置在第15章中讨论。使用一束激光作为光源，激光被一个分光镜分为一束入射光和一束参考光。参考光的光强在出厂时设置，通常在2000至3500Kcps之间。入射光穿过样品池的中央，散射光在向前的角度被检测。因此总的来说对于Zeta电位测量的样品应该光学透明。最高和最低样品浓度可依赖于以下因素： 粒子的光学性质 粒子粒径 粒子的分散度在Zeta电位测量过程中，首先测量参考光的强度，并且显示在Log sheet中。随后检测散射光强度，并由衰减器调节散射光的强度至参考光源的1/10。举个例子说，如果参考光源的光强是2600kcps, 衰减器将会调节散射光强不高于260kcps.如第5章所述，仪器中的衰减器有11个位置，覆盖从100%至0.0003%透射率在Zeta电位测试过程中的最小光强为20kcps，低于此光强测试将中止。Zeta电位测试中的最低浓度在Zeta电位测试过程中所需的最小光强为20kcps。因此最低浓度取决于相对折光指数差（粒子和溶剂间的