纳米粒度与ZETA电位

1、纳米粒度与Zeta电位分析仪,颗粒特性分析测定仪器,英国马尔文公司 激光衍射粒度分析仪 0.02 3500 微米 500/1000 Hz 扫描速率 激光动态光散射分析仪 2 3000纳米/ZETA电位 干粉/喷雾粒度分析仪 在线粒度分析仪 高浓度超声粒度分析仪 绝对分子量测定仪 100 1 e 12 Daltons 高浓度背散射粒度分析仪 0.6 6000nm ! (New!),美国康塔公司 全自动比表面及孔隙度分析仪 (分析站数可选 1/2/3/6) 0.005 m2/g 3.5 5000 埃 压汞仪 3.6纳米 426 微米孔径 化学吸附仪 (TPR/TPD) 流动法快速比表面测定仪 全自

2、动真密度计 自动堆密度分析仪,英国马尔文仪器有限公司 _激光粒度分析仪的创始人- 世界上最大的激光粒度分析仪专业设计和生产厂家- 世界上第一台相关处理器- 世界上第一台激光衍射法粒度分析仪，- 世界上第一台激光PCS粒度分析仪- 世界上第一台超声粒度分析仪- 销售量占世界第一，仅中国大陆已有700台以上- 已获得ISO9001标准, 欧洲EMC标准认证, GMP标准认 证，唯一完全符合美国FDA QSpec要求- 多方位应用支持，在中国设立了技术服务中心- 全国现有上海，北京，广州，成都，西安五个办事处（沈阳办事处在筹建 中），共有七个专业服务工程师，可提供及时完善的专业服务,.,.,.,.,

3、.,.,.,激 光 粒 度 分 析 技 术 的 先 锋,常见粒度分析方法,统计方法 代表性强, 动态范围宽 分辨率低 筛分方法 38微米- 沉降方法 0.01-300微米 光学方法 0.001-3500微米,非统计方法 分辨率高 代表性差, 动态范围窄 重复性差 显微镜方法 光学 1微米- 电子0.001微米- 电域敏感法 0.5-1200微米,光学方法,激光衍射方法( 0.02-3500微米) PCS 光子相关光谱方法( 0.001-6000纳米) 光阻方法(0.01-250微米) 英国马尔文仪器公司 世界最大的专业设计及制造厂家,激光衍射方法,The Principle,Small par

4、ticles scatter light at wide angles,Laser,Particles,Detector,Fourier Lens,Beam,Large particles scatter light at narrow angles,PHOTON CORRELATION SPECTROSCOPY (PCS)光相关光谱纳米粒度分析仪Zeta电位分析仪,INTERACTION OF LIGHT WITH MATTER: MIE THEORY,什么是光相关光谱( PCS)?,相关器工作原理,Large Particles,Perfect Correlation,Small Part

5、icles,G,1.00,0,t =0,Time,t =,检测难点,小粒子 信号非常弱 样品浓度与多重散射,新一代纳米粒度及电位分析仪,2003年5月全新推出Nano系列 多种组合: 粒度，电位，检测角度，自动滴定系统 ZS: 173度检测，0.6-6000nm, 0.1PPM-40% ZS90: 90度检测,1-3000nm 特点: 高灵敏度APD检测器 最新技术相关器: 非侵入式背散射专利(NIBS):提高灵敏度,宽浓度范围 M3专利 新一代PALS技术 新一代专利折叠式毛细管样品池 可与自动滴定系统组成在线分析,新一代纳米粒度及电位分析仪,新一代纳米粒度及电位分析仪,THE ZETASI

6、ZER RANGE,用微量电泳法测定水和非水体系中粒子的Zeta电位 Zeta 电位可权威地预测分散体系(悬浮液，乳化液)的长期稳定性 用光相关光谱测量分散体系中粒径分布,提高灵敏度,通常牺牲准确性，用增加激光能量来提高散射光强度,使用高能量激光器的缺点,增加样品吸光度会导致样品发热，破坏稳定性 不可预测的安全限量 增加成本,最好的方法是使用高灵敏监测器提高计数率,ZETASIZER HS (HIGH SENSITIVITY),马尔文推出新型光子电子计数器检测器(new generation of avalanche photodiodes (APDs) 优越性： 提高灵敏度,至少20倍(比传

7、统PM-光电背增管检测器) 可在极低浓度下测量，不需增加激光能量 避免热扰动效应，保证结果准确 延长仪器使用寿命，降低故障率,雪崩式光子电子计数检测器,固态二极管检测器(Solid state diode detectors) 当光子撞击时，产生了电子空穴对 产生的高压加速了电子运动 被加速的电子获的足够的能量进一步导致电离度的增加，如同雪崩一样。 最初的光子能雪崩式产生大量的约106 电子这个数量级远大于普通的光电备增器( photomultiplier detector) 因此有了新一代的雪崩式光子电子计数器检测器,应用实例: Absorbing systems,测碳黑样品,计数率越高越好

8、，结果重复性越好,核心部件: 相关器,最新一代相关器 4000通道, 最小采样时间为25纳秒 (前一代512通道,最小采样时间为50纳秒) 可提供更准确的结果,非侵入式背散射 - NIBS 专利,新型专利技术- 非侵入式背散射专利(NIBS) NIBS - Non-Invasive Back-Scatter 检测角度: 173 可大大提高信噪比,灵敏度比90度角提高50倍(因为背景噪音主要为大粒子,信号主要在小角度 可自动调节样品池位置,在高浓度时可消除多重散射,所以样品浓度范围可以很宽:0.1PPM-40%,NIBS(非入侵式背散射)技术,光纤探测 精确确定样品池内的测量部位 增大散射体积

9、提高测量粒径上限 测量低浓度小颗粒的灵敏度增高 0.1mg/mL的溶解酵素 (14,400Da) 测量高浓度 乳液不用稀释 40wt%的硅胶,可自动调节测量位置以减低吸收与提高信噪比,Cholesterol387Da, 20mg/ml,Hydrodynamic diameter = 0.64nm,ZETA POTENTIAL,WHAT IS ZETA POTENTIAL?,Zeta 电位是一个粒子在特定介质中获得的全部电荷，它不同与表面电荷 Zeta电位可判断分散体系的稳定性 pH, 盐浓度和其它添加剂可改变分散体系中粒子的Zeta电位，由此可研究分散体系的稳定性的机理。 Zeta电位越高，稳

10、定性越好。,Stern layer,ZETA POTENTIAL,Within the diffuse layer is a notional boundary (the slipping plane) within which the particle acts as a single entity The potential at this boundary is the ZETA POTENTIAL,Slipping plane,Diffuse layer,-,-100,0,mV,Distance from particle surface,Surface potential,Zeta

11、potential,Particle with negative surface charge,ZETA POTENTIAL,主要检测方法: 1.声波方式: a.测的是动态迁移率,需经换算才可得到,但换算需大量参数: Sound speed ,Heat capacity,Density,Viscosity , Volumetric thermal expansion coefficient,particle size b. 样品与介质的密度一定要差别大,不然测不出,所以这种方法不适合一般乳液,微乳液等,但适合于矿物,陶瓷浆料等 2.电泳方式,How is it Measured (Electr

12、ophoresis),-,-,-,-,-,-,-,-,+,-,ELECTRODE,ELECTRODE,ELECTRICAL ATTRACTION,VISCOUS DRAG,= microns / sec,Volts / cm,Mobility = velocity,electrical field strength,Particle,The Zeta Principle,+,-,Negatively Charged Particle,两种样品池,+,-,+,-,Capillary cell,Dip cell,Dip cell vs Capillary cell,How is it Measur

13、ed?,+,-,Dip cell,Whilst the disposable dip cell looks attractive, the following drawbacks are immediately apparent. In order to maintain uniform electric fields, the electrodes must be relatively close together and of large cross sectional area. Volts applied generates a current. Volts X Amps = Watt

14、s = heating. The temperature must not change otherwise the viscosity will change. Therefore the applied voltage is very limited.,How is it Measured?,+,-,Dip cell,只能加低电压,分辨率不好 Low voltage = Low resolution,How is it Measured?,+,-,Dip cell,Claims that the disposable cell prevents sample contamination i

15、s also clearly nonsense, as this is irrelevant unless the electrodes are also carefully cleaned between samples,毛细管样品池,Higher electric fields possible Higher salt concentration can be measured Less problem with electrode contamination, as the electrodes are cleaned by flushing between samples Automa

16、tion possible. Autotitrator possible,+,-,Capillary cell vs dip cell,Capillary,Dip Cell,Clearly, at higher voltages, we will have much greater resolution in detecting the movement of the particles and hence the Zeta potential,Problems with the Capilliary Cell Electroosmosis & Stationary Layers,Statio

17、nary Layers,最新的技术,M3专利，电场快速，慢速交替变化，可以得到更准确，更高分辨率的结果。 PALS专利，检测相位的变化，灵敏度远远高过传统的检测频率变化,Resolution test of a mixture of DTS0050 latex (-50mV) CML latex (-60mV) Carboxyl latex (-84mV) Sulphate latex (-108mV),M3: HIGH RESOLUTION MODE,www.malvern.co.uk,M3技术可以提供非常好的分辨率, 达1MV,M3: HIGH RESOLUTION MODE,Resolu

18、tion on other instruments without M3,www.malvern.co.uk,Resolution on other instruments without M3 using dip cell.,Phase Analysis of very low mobility data,Zeta电位测量:折叠毛细管样品池,世界上首个折叠毛细管Zeta电位测量样品池 这种包含电极的一次性样品池,不用清洁与维护,不存在样品交叉污染与沉结.也可用于同类样品的多次测量 也可用于颗粒度测量 样品池的紧密吻合设计保证无漏接触.当与选项的MPT自动滴定仪联用时成为自动滴定测量的一部分

19、由于不可能存在样品交叉污染与沉结,测量比使用普通的样品池更可靠,ZETA POTENTIAL AND DISPERSION STABILITY,+30mV 或30mV 可看作稳定不稳定的分界线 30 mV, 和 -30mV 认为是稳定态。,ZETA 电位与散射体系的稳定性,影响ZETA 电位的因素,要了解影响分散体系稳定性的因素, 就要了解下列因素怎样影响Zeta 电位及粒径变化的 pH 电导率 添加剂浓度,这需要作大量的实验，如果使用自动滴定器，这些变化就会重复出现，提高研究效率,MPT-2自动滴定仪,全自动: pH滴定,加酸或碱 电导率滴定,指数渐进加盐 添加剂滴定,线性渐进加添加剂 自动

20、分子量测量 等电点 应用 用于蛋白质总样可小于3ml,MPT-2 自动滴定器的特点,The MPT-2 专为Zetasizer 设计 内存标准自动操作程序Titrator Operating Procedures (TOPs) 3 个独立的进样系统 高效，低成本 小体积,完全匹配 操作简单，参数可选，结果可靠 按程序自动从酸到碱到盐变化 许多用户都配置了自动滴定系统,MPT-2 特点及优越性,精确滴定 轻松使用，维护简单 软，硬件色彩标记显著 内置专家建议方案,滴定精度0.3微升 用户要自已动手的部件降到最少 且可在几分钟更换 操作简单， 专家帮助实时出现,三种滴定方式,pH 滴定 滴加酸或碱

21、 电导滴定 以浓度对数形式的步幅滴加盐添加剂滴定 以设定步幅线性滴加盐和其它添加剂,样品,盐,碱,酸,废弃物,流动池,ZETA 电位与 pH 关系,Pharmaceuticals,Advantages sensitivity, precision, low sample volume, high concentration, ease of use Product formulation Study effects of different components in a formulation on the zeta potential Stability testing Predict l

22、ong term stability Reduce number of trial formulations by selecting only the promising formulations to test Emulsions May not be possible to dilute without changing the size Micro-emulsions 10-40 volume %, cannot dilute Drug delivery,The effect of changing the formulations of products on their long

23、term stability can be studied by measuring the effect on their zeta potential,Zeta Potential Of Vaccine Formulations,-100,0,100,Zeta Potential(mV),2,4,6,8,Intensity,Mean = - 52mV,Formulation A,-100,0,100,Zeta Potential(mV),2,4,6,8,Intensity,Mean = - 24mV,Formulation B,SOME PARTICLE SIZES.,Red Blood

24、Cell.7000nm Bacteria/Yeast Cells.2000-3000nm Smallest particle seen through a light microscope.200nm Viruses10-100nm Mad Cow Disease Prions.10-20nm Protein (lysozyme).3nm,www.malvern.co.uk,Protein Stabilised Emulsions,Effect of protein type,Protein B,3,4,5,6,7,8,9,40,20,0,-20,-40,-60,pH,Zeta Potenti

25、al (mV),pH,Silverson Mixer,Ultrasonic Bath,3,4,5,6,7,8,9,50,40,30,20,10,0,-10,-20,pH,Zeta Potential (mV),Protein Stabilised Emulsions,Effect of preparation procedure,Drug delivery,Formulation of hydrophobic drugs as a stable emulsion, e.g. ICIs Diprivan, Kabi pharmaceuticals Diazamuls Size measureme

26、nt as a function of time has been used to optimise the solubilisation of a drug in a micro-emulsion formulation Zeta potential can be used to monitor the coating efficiency of Poly Ethylene Glycol (PEG) onto liposomes The thickness of a coating polymer layer can be measured a high degree of repeatab

27、ility, which is required to produce useful data,Cyclosporin Microemulsions,% in class,2,4,6,8,1,0,1,2,-,5,0,-,4,0,-,3,0,-,2,0,-,1,0,0,1,0,2,0,Zeta Potential (mV),pH,Nanospheres without F68,Nanospheres with F68,Amphiphilic b-Cyclodextrin Nanospheres,Coated Liposomes: Steric Stabilisation,10-4,0,10-5,

28、10-3,10-2,10-1,Electrolyte Concentration (mol/l),400,600,200,z-Average Diameter (nm),-30,-20,-40,-10,0,Zeta Potential (mV),Stability of Solid Lipid Nanoparticles (SLN),Stability of Solid Lipid Nanoparticles (SLN),Biotechnology,Advantages Low volume, precision, combined size and zeta potential, ease

29、of use Proteomics, the study of proteins and their use in therapeutic applications Examine the effects of salts, heat, pH and organic dispersants on the size Study how conformation (shape) - affects protein functionality Measure molecular weight to study protein binding Improve the extraction of pro

30、teins from a fermentation process,Biotechnology,Applications Gene therapy Thermal stability studies, melting points Protein self-interactions Protein conformation How activity is related to structure, e.g. pH dependence of structure of insulin Peptide characterisation Can aggregate at a critical tem

31、perature, this is dependant on composition and concentration Can be under 2nm at 1,600Da,Gene therapy,Gene therapy is the process by which genetic material is delivered, by means of a vector, to patients for a therapeutic purpose Vectors are delivery vehicles - usually a virus or a liposome - used t

32、o transport the genetic material to target cells in the body Both cationic and anionic liposomes are currently being investigated as vectors for gene therapy,-,6,0,-,4,0,-,2,0,0,2,0,4,0,6,0,Zeta Potential (mV),Molar Ratio of Plasmid:Liposome,1:0.2,1:0.4,1:0.6,1:1.2,1:0.8,1:1,1:1.4,Cationic Liposomes

33、 In Gene Therapy,Measuring Virus: Antibody Interactions,120,140,160,180,200,z-Average Diameter (nm),Protein processing,System requires high sensitivity Proteins measured can be small and dilute which requires a sensitive system to characterise repeatably Size Optimise the conditions of microfiltration of proteins from fermentation broths Zeta potential Minimise aggregates to minimise loss and therefore i