Gel permeation chromatography

About: Gel permeation chromatography is a research topic. Over the lifetime, 10412 publications have been published within this topic receiving 227159 citations.

The Chemist's Companion: A Handbook of Practical Data, Techniques, and References

Abstract: Properties of Molecular Systems I. Properties of Solvents and Common Liquids II. Azeotropic Data III. Empirical Boiling Point-Pressure Relationships IV. Properties of Selected Gases V. Properties of Representative Fused Salt Systems VI. Structure and Properties of Naturally Occurring -Amino Acids VII. Properties and Applications of Liquid Crystals VIII. Prototropic Tautomerism IX. Acids and Bases Properties of Atoms and Bonds I. Properties of the Elements II. Table of Isotopes III. Selected Bond Lengths IV. Effective van der Waals Radii V. Bond Angles and Hybridization VI. Selected Bond Strengths VII. Force Constants VIII. Torsion and Inversion Barriers IX. Bond and Group Dipole Moments X. Aromaticity Kinetics and Energetics I. Activation Parameters and Kinetics of Selected Reactions II. Linear Free Energy Relationships III. Conformational Free Energy Values IV. Free Energy-Composition Chart Spectroscopy I. The Electromagnetic Spectrum II. Solvents and Other Media for Spectral Measurements III. Optical Materials for Spectroscopy and Photochemistry IV. Vibration Spectra V. Electronic Absorption and Emission Spectra: UV and Vis VI. Optical Activity and Optical Rotation VII. Mass Spectrometry VIII. Nuclear Magnetic Resonance Spectroscopy IX. Electron Spin Resonance Spectroscopy X. Nuclear Quadrupole Resonance Spectroscopy XI. Bibliography of Spectral Data Compilations Photochemistry I. Electronic Energy State Diagram II. Excited State Energy Transfer: Sensitizers and Quenchers III. Photochemistry Light Sources and Equipment IV. Chemical Actinometry: Quantum Yield V. Suppliers VI. References Chromatography I. Fundamental Types of Chromatography and Basic Definitions II. Adsorption Chromatography III. Paper Chromatography IV. Column and Thin Layer Partition Chromatography V. Ion-Exchange Chromatography VI. Gel Filtration and Gel Permeation Chromatography VII. Automated Liquid Chromatography VIII. Electrophoresis IX. Vapor Phase Chromatography X. Chromatography Supply Directory XI. References Experimental Techniques I. Properties of Laboratory Materials II. Standard Glassware Cleaning Solutions III. Purification of Common Solvents IV. Detection of Peroxides and Their Removal V. Chemical Methods for Deoxygenating Gases and Liquids VI. Simple Chemical Methods for Detecting Specific Gases VII. Simple Preparations of Some Dry Gases VIII. Common Solvents for Crystallization IX. Solvents for Extraction of Aqueous Solutions X. Drying Agents XI. Solvents and Baths for Heating and Cooling XII. Molecular Weight Determination Mathematical and Numerical Information I. Approved International Units System and General Constants II. Useful Conversion Factors III. Wavelength-Wavenumber Conversion Table IV. Multiples of Element and Group Weights V. Molecular Symmetry: Definitions and Common Systems VI. Character Tables for Common Symmetry Groups VII. Computer Programs VIII. Statistical Treatment of Data Miscellaneous I. Important Chemistry Reference Sources: A Bibliography II. Atomic and Molecular Models III. Addresses of Publishers that Deal With Chemistry IV. Combustion Microanalysis and Other Custom Analytical Services V. Hazards of Common Chemicals Suppliers Index Subject Index

Biodegradable polymers for use in surgery—polyglycolic/poly(actic acid) homo- and copolymers: 1

Abstract: The historical development of polyglycolic acid (PGA) and polylactic acid (PLA) polymers and copolymers for use in surgery is set down. Details of the synthesis of PGA and PLA polymers from their cyclic diesters are described, as well as a series of glycolide/lactide copolymers. The reactions were followed by time sampling techniques. The resulting samples were characterized by gel permeation chromatography (g.p.c.), differential scanning calorimetry (d.s.c.), thermogravimetric analysis (t.g.a.) and 220 MHz proton nuclear magnetic resonance spectroscopy (n.m.r.). Details of these analytical technicques are given. The respective reactivity ratios of glycolide and lactide are elucidated. The effect of 60Co γ radiation on the molecular properties of PGA is also shown.

A universal calibration for gel permeation chromatography

Abstract: Gel permeation chromatography is one of the most powerful techniques for characterizing the polydispersity of polymeric materials. A versatile commercial apparatus has been used successfully in numerous laboratories on various problems of molecular weight distributions. But one of the difficulties still unsolved is the problem of calibration, i.e., the relation between elution volume and molecular weight. Some authors have assumed that retention time depends on the contour length of the molecular chain. Others think that it is more reasonable to use the radius of gyration or some average volume of the polymer molecule as the calibration parameter. In a recent paper we have reported GPC retention times of a series of polystyrenes exhibiting different molecular structures: linear, star-shaped, and comb-like. All were of known molecular weight and of low polydispersity. Obviously the conventional calibration method, where the logarithm of molecular weight is plotted against elution volume, does not ...

Physico-chemical characterization of lignins from different sources for use in phenol–formaldehyde resin synthesis

Abstract: During the last decades lignin has been investigated as a promising natural alternative to petrochemicals in phenol-formaldehyde (PF) resin production, due to their structural similarity. Physico-chemical characterization of three types of lignin, namely kraft pine lignin (L1), soda-anthraquinone flax lignin (L2), and ethanol-water wild tamarind lignin (L3) has been evaluated to determine which one is the most suitable chemical structure for above purpose. Characterization has been performed using Fourier transform infrared spectroscopy (FT-IR) and proton nuclear magnetic resonance spectrometry ((1)H NMR) to analyse the chemical structure, gel permeation chromatography (GPC) for determining molecular weight (MW) and molecular weight distribution (MWD), differential scanning calorimetry (DSC) to measure the glass transition temperature and thermogravimetric analysis (TGA) to follow the thermal degradation. Both structural and thermal characteristics suggest that kraft pine lignin (L1) would be a better phenol (P) substitute in the synthesis of lignin-phenol-formaldehyde (LPF) resins, as it presents higher amounts of activated free ring positions, higher MW and higher thermal decomposition temperature.

Large-scale single-chirality separation of single-wall carbon nanotubes by simple gel chromatography

Abstract: Monostructured single-wall carbon nanotubes (SWCNTs) are important in both scientific research and electronic and biomedical applications; however, the bulk separation of SWCNTs into populations of single-chirality nanotubes remains challenging. Here we report a simple and effective method for the large-scale chirality separation of SWCNTs using a single-surfactant multicolumn gel chromatography method utilizing one surfactant and a series of vertically connected gel columns. This method is based on the structure-dependent interaction strength of SWCNTs with an allyl dextran-based gel. Overloading an SWCNT dispersion on the top column results in the adsorption sites of the column becoming fully occupied by the nanotubes that exhibit the strongest interaction with the gel. The unbound nanotubes flow through to the next column, and the nanotubes with the second strongest interaction with the gel are adsorbed in this stage. In this manner, 13 different (n, m) species were separated. Metallic SWCNTs were finally collected as unbound nanotubes because they exhibited the lowest interaction with the gel.