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The Introduction of the theory in GFFF ,mainly about the HLF(hydrodynamic lift force) and viscosity influence. Lvbo 20120411. Introduce. The FFF(field flow fractionation):the concept of field and flow . GFFF: Particles >1 µm. Applicable to water and organic solvents
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The Introduction of the theory in GFFF ,mainly about the HLF(hydrodynamic lift force) and viscosity influence Lvbo 20120411
Introduce The FFF(field flow fractionation):the concept of fieldand flow. GFFF: Particles >1 µm. Applicable to water and organic solvents Mode: Steric、Hyperlayer（Focus）、Brown Advantage: The simplest design of all FFF methods The cheapest and the most basic Constant gravity field Do not damage to the sample and keep the integrity of the structure and function of them 30cm~50cm Inject 2cm
Application of GFFF micrometer-sized particles: coal particles,silica particles,clay particles,starch granules,yeast,and pollens. Biological: lymphocytes,red blood cells,parasites,stem cells,and bacteria…….
Theory 200um 雷诺系数<2000 Parabolic flow shape r δ X=r+ δ
Theory Steric： Hyperlayer（Focus） Brown
Theory • Research of HLF theory:角度、流体溶液密度、流速、通道厚度。Have been discussed. • Chip
Theory ρm=1000 kg/m3 V=4/3*3.14*a3 m3 ν0=0.833/100 m/s (2ml/min) r =6*10-6 m w=200*10-6 m c=0.0075 η=1.01*10-3 Pa*s
The theory of HLF Flw 11um~31um Fwall 6um~12um <2
The theory of HLF x=6.92275*10-6 Fnet=0 1um
Analysis Stress Analysis,then theory contains G、HLF、and so on. From v to R or inverse. Change conditions to test the S or H and resolution.Both theory and the actual. 1.Drag or Adsorption. 2.HLF(Make γ>1) 3.Rotate when flowing <0.5 <0.005 >=0.5
Selectivity:S 1 2 3 d 与tr 成反比，与R成正比 假设： 即： 假设不成立 凡是由与R成比例的都可以拿来研究其选择性，如：r、x/w、Used以及其它组合等等。
H H实测值： H理论值： 扩散（布朗运动，热运动） 粒子多分散性 sample poly-dispersity 边缘效应 edge effects 非平衡效应 nonuniformities 进样体积 sample volume 柱后效应 extrachannel volumes 终端效应 channel end 。。。。。。
Retention ratio:R 1.Both up and down mode ,the R gradually increased with the channel angle for each of the carrier liquids. 2.Ideal steric FFF:R=6r/w(0.18) only in the case of B1, the lowest viscosity solution do the observed R <=0.18 and γ <1. 3. There does no significant difference in R for upward and downward 4.The different R of A and B indicates that viscosity is not the only factor influencing lift force. The lower ionic strength of A for higher R . UP Down
H actual A（HMPC） UP A（HMPC） DOWN B（HMPC+FL+NaN3）UP B DOWN
H sample volume, sample polydispersity H inj=0.0026 cm The polydispersity contributions are similarly small as H inj and HB HB=0.0020~0.013 cm
1.As the carrier viscosity increases,HLF increase,so the R increasse for both A and B system. 2. The important observation is that analysis times decrease without loss of resolution. 3. Peak symmetry improves(HLF lifting of the particles away from the channel wall),so the resolution do not decrease very much.
Conclusion H S 1. σ η HLF R r Cosθ 2. The zone broadening is apparently not strongly influenced by carrier viscosity so that the analysis times may be reduced without loss of resolution. 3. the contributions to H due to sample volume, sample polydispersity, and Brownian motion have been shown to be small compared to the measured plate heights.
