9 Environmentally Friendly Synthesis of Polymer-Grafted Nanoparticles
Inorganic nanoparticles such as silica, and titanium oxide, are widely used industrially as fillers and pigments for polymer materials, because inorganic nanoparticles have excellent properties such as chemical, heat and weather resistance, lightweight, thermal conductivity and low thermal expansion. On the other hand, nanocarbons, such as carbon black, nanodiamond, and carbon nanotube, are well known as one of the industrially important carbon materials. Carbon materials also have outstanding properties such as electro-conductivity, heat-resistance, biocompatibility, and chemical-resistance. Carbon nanotubes in particular have attracted attention as nanotechnology related materials. In general, dispersing inorganic nanoparticle and nanocarbons uniformly into a polymer or an organic solvent is very difficult because of aggregation. In addition, the mechanical properties of polymer composite from nanoparticles and nanocarbons are considered to depend on not only the mechanical properties of the polymer matrix but also on the properties of interfacial regions between surface of nanoparticles and matrix polymers. The chemical and physical modifications of inorganic nanoparticle and nanocarbon surfaces, therefore, have been extensively studied. The chemical modification of surfaces is permanent, but physical modification is temporary. We have pointed out that the dispersibility of silica nanoparticles and nanocarbons is extremely improved by surface grafting of polymers, namely, chemical binding of polymers, onto nanoparticle and nanocarbon surfaces (Tsubokawa, 1999; Tsubokawa, 2002; Tsubokawa, 2007). In addition grafting of polymers onto these surfaces interests us for designing new functional composite materials which have the excellent properties both of nanoparticles as mentioned above and of grafted polymers, such as photosensitivity, biorepellent activity, antibacterial activity, and pharmacological activity (Tsubokawa, 2007). We have succeeded in the grafting of various polymers such as vinyl polymer (Tsubokawa et al., 1988a; Tsubokawa et al., 1990; Fujiki et al., 1990; Tsubokawa et al., 1992a), polyester (Tsubokawa et al., 1982; Tsubokawa et al., 1983), polyether (Tsubokawa et al., 1986; Tsubokawa et al., 1988b), poly(organophosphazene) (Tsubokawa et al., 1992b), and poly(dimethysiloxane) (Tsubokawa et al., 1992c) onto silica nanoparticle and carbon black surfaces using surface functional groups as grafting sites. Furthermore, many experimental attempts by other researchers also have been made to graft polymers onto silica nanoparticle and carbon black surfaces.
Radical graft polymerization of vinyl monomers onto nanoparticles in ionic liquid initiated by azo groups introduced onto the surface
The radical graft polymerization of vinyl monomers, such as styrene and methyl methacrylate, initiated by azo groups introduced onto silica nanoparticle and carbon black surfaces in room temperature ionic liquid (IL) were investigated. In this work, 1-butyl-3-methylimidazolium hexafluorophosphate ([C 4 mim][PF 6 ]) was used as IL. The percentage of polystyrene and poly(methyl methacrylate) grafting onto silica nanoparticle and carbon black increased with increasing reaction time. The percentage of grafting in IL was much larger than that in 1,4-dioxane. The molecular weight of polystyrene grafted onto the silica surface in IL was almost equal to that in 1,4-dioxane. The result indicates that the amount of grafted polystyrene in IL is five times that in 1,4-dioxane. This may be due to the fact that lifetime of the surface radical formed by the group of azo is prolonged because of high viscosity of IL. Therefore, the surface azo groups were effectively used as initiating sites for the graft polymerization. In addition, the reduction of waste solvent was achieved by use of IL as reaction solvent, because unreacted monomer could be removed under vacuum after the reaction and the reuse of IL was easily achieved.
Philosophy of Education
LIST OF FIGURES PREFACE ACKNOWLEDGEMENTS 1 Philosophy of Education Before the Twentieth Century Socrates and Plato Aristotle Rousseau Pestalozzi, Herbart, and Froebel Summary Questions Introduction to the Literature 2 The Philosophical and Educational Thought of John Dewey Dewey's Philosophical Orientation The Meaning and Aims of Education Dewey's Psychology Dewey's Theory of Knowledge Democracy and Education The Place of Subject Matter Dewey Today: An Assessment Summary Questions Introduction to the Literature 3 Analytic Philosophy Philosophical Analysis in Education The Analysis of Teaching Current Analyses of Teaching Summary Questions Introduction to the Literature 4 Continental Philosophy Existentialism Phenomenology Critical Theory Hermeneutics Postmodernism Summary Questions Introduction to the Literature 5 Logic and Critical Thinking Formal Logic Informal Logic McPeck's View of Critical Thinking An Alternative Approach Summary Questions Introduction to the Literature 6 Epistemology and Education Justified True Belief Foundationalism Truth Nonfoundational Theories of Knowledge Epistemology and Education Constructivism Summary Questions Introduction to the Literature 7 Philosophy of Social Science and Educational Research How Does Science Grow? A Debate in Educational Research Some Examples Summary Questions Introduction to the Literature 8 Ethics and Moral Education Pre-Enlightenment Ethics Enlightenment Ethics Utilitarianism Deweyan Ethics Moral Education Cognitive Developmentalism Summary Questions Introduction to the Literature 9 Social and Political Philosophy The Current Debate Justice and Equality in Education Summary Questions Introduction to the Literature 10 Problems of School Reform Equality Accountability Standards Testing Summary Questions Introduction to the Literature 11 Multiculturalism and Cosmopolitanism Multiculturalism Cosmopolitanism The Educator's Dilemma Summary Questions Introduction to the Literature 12 Feminism, Philosophy, and Education Feminist Critiques of Philosophy Epistemology Philosophy of Social Science Ethics Care and Education Summary Questions Introduction to the Literature NOTES BIBLIOGRAPHY INDEX