Journal of Colloid Science最新文献_第4页

Rates of flocculation and deflocculation in dispersions of carbon black in hydrocarbons 碳氢化合物中炭黑分散体的絮凝和反絮凝速率

Journal of Colloid Science Pub Date : 1965-09-01 DOI: 10.1016/0095-8522(65)90041-3

Paul C Hiemenz , Robert D Vold

{"title":"Rates of flocculation and deflocculation in dispersions of carbon black in hydrocarbons","authors":"Paul C Hiemenz , Robert D Vold","doi":"10.1016/0095-8522(65)90041-3","DOIUrl":"10.1016/0095-8522(65)90041-3","url":null,"abstract":"<div>The optical density of carbon black suspensions in heptane, toluene, and solutions of polystyrene in toluene and in cyclohexane, decreases with time and ultimately reaches a steady-state value. This is interpreted in terms of the simultaneous occurrence of flocculation and deflocculation following, respectively, second- and first-order kinetic rate laws. A method is developed for obtaining an absolute value of β, the rate constant for deflocculation, from the time dependence of the optical density, assuming that optical density is proportional to floc concentration.The rate constants for both flocculation and deflocculation increase with increasing initial average size of the flocs. The specific rate of redispersion, β, increases with increasing polystyrene concentration in cyclohexane, the effect being explicable in terms of decrease of attraction between carbon particles due to the presence of tightly adsorbed polymer on the surface. In toluene, β passes through a minimum with increasing polystyrene concentration, attributable to decreased redispersion resulting from bridging of particles by extended loops of adsorbed polymer.</div>","PeriodicalId":15437,"journal":{"name":"Journal of Colloid Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1965-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0095-8522(65)90041-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79384890","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 14

Monolayer studies. II. Electron microscopy of normal paraffinic polar compounds 单层的研究。2正构烷烃极性化合物的电子显微镜

Journal of Colloid Science Pub Date : 1965-09-01 DOI: 10.1016/0095-8522(65)90049-8

Erwin Sheppard, Ronald P Bronson, Noubar Tcheurekdjian

引用次数: 17

Deposition of aerosol flowing past a cylindrical fiber in a uniform electric field 气溶胶在均匀电场中流过圆柱形纤维的沉积

Journal of Colloid Science Pub Date : 1965-08-01 DOI: 10.1016/0095-8522(65)90033-4

G Zebel

{"title":"Deposition of aerosol flowing past a cylindrical fiber in a uniform electric field","authors":"G Zebel","doi":"10.1016/0095-8522(65)90033-4","DOIUrl":"10.1016/0095-8522(65)90033-4","url":null,"abstract":"<div>The deposition of aerosol particles from an air stream of velocity V0 upon a circular cylindrical fiber perpendicular to the stream in a homogeneous electrical field E0, has been investigated theoretically. The dielectric constant ϵc of the fiber controls by means of the parameter <math><mtext>a = </mtext><mtext>(ϵ</mtext><msub><mi></mi><mn>c</mn></msub><mtext> − 1)</mtext><mtext>(ϵ</mtext><msub><mi></mi><mn>c</mn></msub><mtext> + 1)</mtext></math> the additive inhomogeneous field of the fiber, which effectuates the deposition of the particles. When computing the trajectories, both inertia and image forces for charged particles have been neglected. The computations have been made for frictionless potential flow and for viscous flow according to Lamb.For uncharged particles, the dimensionless parameter F ∼ r83E02B/rcV0 (where rs, B = radius and mobility of the particle; rc = radius of the fiber) determines the value of the deposition coefficient. Exact solutions for the limiting case a = 0 as well as some approximate solutions for a ≠ 0, obtained by the Runge-Kutta method, are given.For particles carrying an electrical charge q, the dimensionless parameter G = E0qB/V0 is decisive. From the exact solutions the deposition coefficient is given by <math><mtext>ζ = </mtext><mtext>G(a + 1)</mtext><mtext>(G + 1)</mtext><mtext>, </mtext><mtext>if</mtext><mtext> G > 0</mtext></math>, for ideal and viscous flow. With negative G, the fiber may be surrounded by a “dust-free space.”</div>","PeriodicalId":15437,"journal":{"name":"Journal of Colloid Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1965-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0095-8522(65)90033-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80230356","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 102

Theory of thermophoresis of large aerosol particles 大气溶胶粒子的热泳动理论

Journal of Colloid Science Pub Date : 1965-08-01 DOI: 10.1016/0095-8522(65)90035-8

B. Derjaguin, Y. Yalamov

引用次数: 93

An apparatus to study the collision and coalescence of liquid aerosols 一种研究液体气溶胶碰撞和聚合的装置

Journal of Colloid Science Pub Date : 1965-08-01 DOI: 10.1016/0095-8522(65)90039-5

J. Schneider, N. Lindblad, C. Hendricks

引用次数: 35

Charging and decay of monodispersed aerosols in the presence of unipolar ion sources 单极离子源存在下单分散气溶胶的充电和衰变

Journal of Colloid Science Pub Date : 1965-08-01 DOI: 10.1016/0095-8522(65)90037-1

Kenneth T Whitby, Benjamin Y.H Liu, Carl M Peterson

引用次数: 13

Aerosol studies by light scattering. IV. Preparation and particle size distribution of aerosols consisting of concentric spheres 光散射研究气溶胶。四、由同心球组成的气溶胶的制备及粒径分布

Journal of Colloid Science Pub Date : 1965-08-01 DOI: 10.1016/0095-8522(65)90032-2

W.F Espenscheid , E Willis, E Matijević , M Kerker

{"title":"Aerosol studies by light scattering. IV. Preparation and particle size distribution of aerosols consisting of concentric spheres","authors":"W.F Espenscheid , E Willis, E Matijević , M Kerker","doi":"10.1016/0095-8522(65)90032-2","DOIUrl":"10.1016/0095-8522(65)90032-2","url":null,"abstract":"<div>Coated aerosols consisting of silver chloride spheres encased in a concentric shell of linolenic acid have been prepared and their particle size distribution analyzed by light scattering. The procedure involves preparation of a silver chloride aerosol of uniform particle size by condensation of silver chloride vapor upon sodium chloride nuclei in a high temperature generator. The size distribution of the silver chloride aerosol particles is determined by light scattering using the polarization ratio method and is confirmed by electron microscopy. The vapors of linolenic acid are next condensed upon the silver chloride particles forming the coated aerosols. These are then analyzed by the polarization ratio method using the theory of scattering by concentric spheres. In order to simplify the computations a model is assumed for which either the thickness of the coating on each particle is constant or the volume of coated material is constant. For the range of parameters used here, both models give equivalent results. The linolenic acid can be fixed by OsO4 and the size distribution of the coated aerosols also confirmed by electron microscopy.</div>","PeriodicalId":15437,"journal":{"name":"Journal of Colloid Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1965-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0095-8522(65)90032-2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"16902153","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 30

Theory of thermophoresis of large aerosol particles 大气溶胶粒子的热泳动理论

Journal of Colloid Science Pub Date : 1965-08-01 DOI: 10.1016/0095-8522(65)90035-8

B.V Derjaguin, Yu Yalamov

引用次数: 92

Measurement of aerosol concentrations with a hot wire anemometer 用热线风速计测量气溶胶浓度

Journal of Colloid Science Pub Date : 1965-08-01 DOI: 10.1016/0095-8522(65)90040-1

Victor W Goldschmidt

引用次数: 19

Some remarks about the coagulation of aerosol particles by Brownian motion 关于布朗运动使气溶胶粒子凝聚的几点看法

Journal of Colloid Science Pub Date : 1965-08-01 DOI: 10.1016/0095-8522(65)90030-9

G. Hidy, J. Brock

引用次数: 35