北京化工大学：《物理化学》课程教学资源（双语读书报告）What is Colloid

ata Collod? 小组成员：赵春莉 刘生艳 田琦 www.china.cn PDF文件使用"pdfFactory Pro”试用版本创建t.fineprint..com.cn

小组成员：赵春莉 刘生艳 田琦 PDF 文件使用 "pdfFactory Pro" 试用版本创建 ÌÌÌ www.fineprint.com.cn

Foreword Colloid Science is often described as an aenablingo discipline. The structure,theories,rules,skills or techniques of the colloid scientist allow us to think about what Gibbs called heterogeneous systems,where surface or interfacial energy. The skills of the colloid scientist enable the industrial scientist to resolve challenging physicochemical problems in practice or in the real world PDF文件使用"pdfFactory Pro”试用版本创建wm,fineprint..com,c四

Foreword • Colloid Science is often described as an ªenablingº discipline. • The structure, theories, rules, skills or techniques of the colloid scientist allow us to think about what Gibbs called heterogeneous systems, where surface or interfacial energy. • The skills of the colloid scientist enable the industrial scientist to resolve challenging physicochemical problems in practice or in the real world PDF 文件使用 "pdfFactory Pro" 试用版本创建 www.fineprint.com.cn

Colloids are ubiquitous,and for centuries they have been of scientific and technological interest.The last decade however,has seen significant advances made in the preparation of colloids of various sizes with diverse and tailored composition. The realm of technological applications of colloids will rapidly expand,thus inspiring research in the area of colloids and colloid assemblies well ac-counts of the current state of research in the various fields. PDF文件使用"pdfFactory Pro”试用版本创建ww,fineprint.com.c四

• Colloids are ubiquitous, and for centuries they have been of scientific and technological interest. The last decade, however, has seen significant advances made in the preparation of colloids of various sizes with diverse and tailored composition. • The realm of technological applications of colloids will rapidly expand, thus inspiring research in the area of colloids and colloid assemblies well ac-counts of the current state of research in the various fields. PDF 文件使用 "pdfFactory Pro" 试用版本创建 www.fineprint.com.cn

Deinition 。米米 米 米 米 米 Colloid systems usually have dimensions of less than 1 micron,which results in a very high surface- to-volume ratio.Therefore,surface chemistry plays a very important part in the study of colloidal systems. 米 .Lindkyist.com 米 PDF文件使用"pdfFactory Pro”试用版本创建w.fineprint.com.cn

• Colloid systems usually have dimensions of less than 1 micron, which results in a very high surface￾to-volume ratio. Therefore, surface chemistry plays a very important part in the study of colloidal systems. PDF 文件使用 "pdfFactory Pro" 试用版本创建 www.fineprint.com.cn

Why Surface Modification? surface modification of colloid particles of various nature and size 1 has be-come a very common practice during he last few decades for a 05 umber of reasons.This section describes the 10 most relevant objectives x4=00 That lead to the design of 80 0 聊 procedares aiming to a Wariengurim) ntrolled surface PDF文件使用"pdfFactory Pro”试用版本创建ww.fineprint.com,cn

Why Surface Modification? • The surface modification of colloid particles of various nature and size has be-come a very common practice during the last few decades for a number of reasons. This section describes the most relevant objectives that lead to the design of procedures aiming to a controlled surface modification. PDF 文件使用 "pdfFactory Pro" 试用版本创建 3www.fineprint.com.cn

Chemical and Colloidal Stability 胶体稳定性 Similarly,many ·Major problems to be semiconductor overcome in nanoparticles,such as nanoparticle metal chalcogenides, dispersions are the are air sensitive,so that degradation of the they can be completely material through dissolved in the chemical etching and presence of oxygen and the agglomeration light.These processes caused by strong van will be discussed below, der Waals attractive as well as possible forces. means to prevent them. PDF文件使用"pdfFactory Pro”试用版本创建www.fineprint.com.cn

Chemical and Colloidal Stability 胶体稳定性 • Similarly, many semiconductor nanoparticles, such as metal chalcogenides, are air sensitive, so that they can be completely dissolved in the presence of oxygen and light. These processes will be discussed below, as well as possible means to prevent them. • Major problems to be overcome in nanoparticle dispersions are the degradation of the material through chemical etching and the agglomeration caused by strong van der Waals attractive forces. PDF 文件使用 "pdfFactory Pro" 试用版本创建 www.fineprint.com.cn

。 On the other hand,colloidal Colloid Particles stability is always a relevant issue when inorganic(lyophobic) nanoparticles are synthesized in liquid solvents.The main forces affecting colloidal stability are (attractive)van der Waals forces and(repulsive)double layer and steric interactions. Adsorption In the case of aqueous dispersions (and,in general,in polar solvents),double-layer interactions will be primarily involved in the separation of colloid particles from each other, while for dispersions in non- polar solvents,steric effects due to adsorbed organic chains will be of major relevance. PDF文件使用"pdfFactory Pro”试用版本创建w,fineprint.com,c里

• On the other hand, colloidal stability is always a relevant issue when inorganic (lyophobic) nanoparticles are synthesized in liquid solvents. The main forces affecting colloidal stability are (attractive) van der Waals forces and (repulsive) double layer and steric interactions. In the case of aqueous dispersions (and, in general, in polar solvents), double-layer interactions will be primarily involved in the separation of colloid particles from each other, while for dispersions in non￾polar solvents, steric effects due to adsorbed organic chains will be of major relevance. PDF 文件使用 "pdfFactory Pro" 试用版本创建 www.fineprint.com.cn

As a consequence,compared to micron- sized particles,nanosized particles exhibit different flocculation and coagulation behavior. Hence,they require different mechanisms toachieve colloid stability. PDF文件使用"pdfFactory Pro”试用版本创建m,fineprint.com,c四

• As a consequence, compa red t o mi c r on￾s i z ed pa r t i c l e s , nanos i z ed pa r t i c l e s exh i b i t d i f f e r e n t f l o c cu l a t i o n and coagu l a t i o n behav i o r. • Hence, t hey r equ i r e d i f f e r en t mechan i sms t oac h i e ve co l l o i d s t ab i l i t y . PDF 文件使用 "pdfFactory Pro" 试用版本创建 www.fineprint.com.cn

500nm 30 nm 500国 d 500nm 200nm PDF文件使用"pdfFactory Pro”试用版本创建w,fineprint.com,c四

Colloid Picture Shows PDF 文件使用 "pdfFactory Pro" 试用版本创建 www.fineprint.com.cn

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PDF 文件使用 "pdfFactory Pro" 试用版本创建 www.fineprint.com.cn