Poly(N-isopropylacrylamide): experiment, theory and application
About: This article is published in Progress in Polymer Science.The article was published on 1992-01-01. It has received 4701 citations till now.
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TL;DR: Development of environmentally sensitive hydrogels with a wide array of desirable properties can be made is a formidable challenge, however, if the achievements of the past can be extrapolated into the future, it is highly likely that responsive hydrogelWith such properties can been made.
4,216 citations
TL;DR: The majority of examples, discussed in this paper, deal with pH-responsive drug delivery system, and Thermo-responsive polymer is also covered to a large extent, as well as double-responsive system.
2,746 citations
TL;DR: The exciting successes in taming molecular-level movement thus far are outlined, the underlying principles that all experimental designs must follow, and the early progress made towards utilizing synthetic molecular structures to perform tasks using mechanical motion are highlighted.
Abstract: The widespread use of controlled molecular-level motion in key natural processes suggests that great rewards could come from bridging the gap between the present generation of synthetic molecular systems, which by and large rely upon electronic and chemical effects to carry out their functions, and the machines of the macroscopic world, which utilize the synchronized movements of smaller parts to perform specific tasks. This is a scientific area of great contemporary interest and extraordinary recent growth, yet the notion of molecular-level machines dates back to a time when the ideas surrounding the statistical nature of matter and the laws of thermodynamics were first being formulated. Here we outline the exciting successes in taming molecular-level movement thus far, the underlying principles that all experimental designs must follow, and the early progress made towards utilizing synthetic molecular structures to perform tasks using mechanical motion. We also highlight some of the issues and challenges that still need to be overcome.
2,301 citations
TL;DR: In this article, the authors focused on temperature and pH responsive polymer systems and additionally the other stimuli-based responsive polymers will be assessed, which is more helpful to design new approaches because the basic concepts and mechanisms are systematically connected.
2,233 citations
Cites background from "Poly(N-isopropylacrylamide): experi..."
...[59] Schild HG....
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...1a) is the most popular temperature-responsive polymer since it exhibits a sharp phase transition in water (LCST) at around 32 8C [59]....
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...Phase separation between the collapsed polymer molecules and the expelled water follows this cloud point [59]....
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TL;DR: There is a highly promising role of stimuli-responsive nanocarrier systems for drug and gene delivery in the future with greater understanding of the difference between normal and pathological tissues and cells.
1,993 citations
References
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Book•
01 Jan 1985
TL;DR: The forces between atoms and molecules are discussed in detail in this article, including the van der Waals forces between surfaces, and the forces between particles and surfaces, as well as their interactions with other forces.
Abstract: The Forces between Atoms and Molecules. Principles and Concepts. Historical Perspective. Some Thermodynamic Aspects of Intermolecular Forces. Strong Intermolecular Forces: Covalent and Coulomb Interactions. Interactions Involving Polar Molecules. Interactions Involving the Polarization of Molecules. van der Waals Forces. Repulsive Forces, Total Intermolecular Pair Potentials, and Liquid Structure. Special Interactions. Hydrogen-Bonding, Hydrophobic, and Hydrophilic Interactions. The Forces between Particles and Surfaces. Some Unifying Concepts in Intermolecular and Interparticle Forces. Contrasts between Intermolecular, Interparticle, and Intersurface Forces. van der Waals Forces between Surfaces. Electrostatic Forces between Surfaces in Liquids. Solvation, Structural and Hydration Forces. Steric and Fluctuation Forces. Adhesion. Fluid-Like Structures and Self-Assembling Systems. Micelles, Bilayers, and Biological Membranes. Thermodynamic Principles of Self-Assembly. Aggregation of Amphiphilic Molecules into Micelles, Bilayers, Vesicles, and Biological Membranes. The Interactions between Lipid Bilayers and Biological Membranes. References. Index.
18,048 citations
Book•
01 Jan 1985
TL;DR: In this paper, the authors describe a chain transfer characterisation of polymers charge-transfer complexes, charge transfer complexes and charge transfer complexes of charge transfer and charge-Transfer complexes.
Abstract: Cellular Materials Cellulose Cellulose, Biosynthesis Cellulose, Graft Copolymers Cellulose, Microcrystalline Cellulose Derivatives Cellulose Esters, Inorganic Cellulose Esters, Organic Cellulose Ethers Cement Additives Chain-Reaction Polymerization Chain Transfer Characterization of Polymers Charge-Transfer Complexes Chelate- Forming Polymers Chemical Analysis Chemically Resistant Polymers Chitin Chloroprene Polymers Chlorotrifluorethylene Polymers Chromatography Classification of Polymerization Reactions Coating Methods Coatings Coatings, Electrodeposition Cold Forming.
7,256 citations
Book•
01 Jan 1986
TL;DR: In this paper, the authors present a model for the behavior of polymers in the Liquid Crystalline State (LCS) and the Amorphous State (ACS).
Abstract: Chain Structure and Configuration. Molecular Weights and Sizes. Concentrated Solutions and Phase Separation Behavior. The Amorphous State. The Crystalline State. Polymers in the Liquid Crystalline State. Glass-Rubber Transition Behavior. Cross-Linked Polymers and Rubber Elasticity. Polymer Viscoelasticity and Rheology. Mechanical Behavior of Polymers. Modern Topics. Index.
2,701 citations
TL;DR: In this paper, a lower critical solution temperature of poly(N-isopropyl acrylamide was found to be due to an entropy effect, which was attributed to the formation of nonpolar and intermolecular hydrogen bonds.
Abstract: Aqueous solutions of poly(N-isopropyl acrylamide) show a lower critical solution temperature. The thermodynamic properties of the system have been evaluated from the phase diagram and the heat absorbed during phase separation and the phenomenon is ascribed to be primarily due to an entropy effect. From viscosity, sedimentation, and light-scattering studies of solutions close to conditions of phase separation, it appears that aggregation due to formation of nonpolar and intermolecular hydrogen bonds is important. In addition, a weakening of the ordering effect of the water-amide hydrogen bonds as the temperature is raised contributes to the stability of the two-phase system.
2,698 citations