智能材料英文PPT

高 材 03班 余 函 帅 婉 华 Main contentOverview of smart polymer materialsClassification and application of smart polymer materialsOutlook of smart polymer materials Intelligent material : It is also known as smart material, which has the function of perception, self diagnosis, self adaptation and self repair.Features:polymer materials integrating perception, driver and information processing, to form an intelligent properties similar to the biological material. Biological function of the Intelligent materials Have feedback systemInformation accumulation and recognition functionLearning ability and predictive functionResponse functionSelf repairing functionSelf diagnostic functionDynamic balance and adaptive function A material system with the form of the above structure, it may be reflected of the following characteristics:With sensing capabilities, can detect the outside world (or internal) of the stimulus intensityWith information transfer function, to set up the optimal way to choose and control responseFunction of response and execution to the environmental transformationSensitive responseThe external stimulus can quickly return to the original state. Intelligent material Intelligent metal materialsIntelligent inorganic non metallic materialsIntelligent polymer materialsadvantanges 1.Multi level structure2.Weak intermolecular forcesSide chain is easy to introduce functional groups3.Facilitate molecular design and fine control4.Easy coating Conducive to the perception of the environment to achieve environmental response Classification of intelligent polymer materials Smart polymer gel Shape memory polymer materials Intelligent polymer composites Definition of polymer gelsnThe gel is between liquid and solid material form . Polymer gel is made up of molecules between three-dimensional crosslinked network, its network consists of the macromolecular main chain and side chain with hydrophilic groups (polarity) and hydrophobic groups, or (and) dissociative group, solvent was fixed in the molecular network.nAlthough solvent can not be dissolved the three dimensional network structure of polymer, but high molecular compound solvent affinity groups part can through solvent effect and make the polymer swelling, this also is one of the reasons for the formation of polymer gel. Definition of polymer gelsThree dimensional network structure of polymer gelsThe system of three-dimensional polymer network and solvent Solvent swelling, which can be solvent swelling Biggest feature: volume phase transitionThe polymer gel, which can be chemically bonded, can be chemically and physically cross-linked. Classification of polymer gelsAccording to the classification of solvent in the polymer network:Polymer gel HydrogelOrganic gel lHydrogels are the most common and one of the most important polymer gels. The vast majority of creatures, the presence of natural plant gel and many synthetic polymer gel are belong to the hydrogel. And biological gel have excellent intelligence and high strength.lIntelligent hydrogel is a kind of hydrogel which can produce sensitive response to external stimuli.lHydrogels can absorb hundreds of times beyond the weight of water,so it is also used in health materials.Classification of polymer gels The volume phase transition of gel: Gel equilibrium swelling volume changes with the changes of the environment.Swelling phase Contraction phaseEnvironmental factors changeVolume discontinuityInternal cause: Fan Dehua force, hydrogen bond, hydrophobic interaction and electrostatic force. Preparation of smart polymer gelsStarting materialMonomer (water soluble or oil soluble monomer)Polymers (natural or synthetic polymers)Mixtures of monomers and polymersTwo premises:The main chain or side chain with a large number of Pro solvent groupsAppropriate crosslinking network structurePreparation method:Crosslinking polymerization of monomersGraft copolymerization Chemical initiator Radiation technology Free radical polymerization or copolymerizationMonomer smart polymer gelsOther cross-linking or transformation, etc. Olefin monomer Covalent attachment Natural polymer (starch cellulose) and its derivatives Application of polymer gelChemical film and chemical valvel For intelligent large molecules, their conformation can be changed due to the small changes in the external conditions, and the change may be lost due to the disappearance of the change of external conditions.l It is based on this kind of controllable conformational change of intelligent macromolecule, which is designed and produced a variety of molecular weight which can be controlled to separate membrane.l For example, at the end of disulfide bond poly L2 glutamic acid grafted onto a polycarbonate membrane pore structure, the use of this molecule in the low pH conformation shrinkage, high pH conformation stretching controlling membrane pore size. Experiments show that the membrane water permeability dependence on the pH of the solution and changes in the ionic strength of the solution will also affect the water permeability, with the increase of the ionic strength, water permeability on the pH dependence decreases. chemical mechanical devicev Different hydrogel composite, making a wide variety of chemical mechanical devices. When stimulated, these materials can be bent into a predetermined shape, when the stimulus disappears, the material is returned to the original shape.v For example, the PNIPAM gel was modified at four equally spaced points on a temperature insensitive PAM gel. At room temperature, the composite material is shaped in a straight line, but when the temperature rises, composite gel in the PNIPAM modified at began to bend, forming a pentagonal, then continue to bend so as to form a square pattern, cooling, reverse bending process, materials and recovery is a linear type. According to this, the design and manufacture of the gel hand and other gel device can be grabbed.Application of polymer gel drug control releaseTo smart polymer materials as the basis, it can make the drug release system intelligence, drug is released when needed, otherwise not be released. The characteristics of this system integrating drugs and whether agents on their own judgment, set of sensing, processing and executive function in a body, it can signal a change in the perceived disease caused by chemical and physical quantities, pharmaceutical according to this response to the signal from the feedback and release drug or termination of the release.In fact, the smart type of large molecules and large molecular hydrogels for biomedical applications are more reflected in the drug immobilization and controlled release.Application of polymer gel With the development of material science, the smart polymer material has broad development space and application prospect.