Polyacrylamide gels. Process of network formation

Baselga, Juan; Llorente, M. A.; Hernández-Fuentes, I.; Piérola, Inés F.

doi:10.1016/0014-3057(89)90189-4

Cited by 55 publications

(45 citation statements)

References 24 publications

(24 reference statements)

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“…The different reaction rates of the comonomers lead to a shift in the instantaneous relative comonomer concentration (Baselga et al 1988, 1989). The reaction rates of the growing copolymer chains are not only dependent on the number of monomer units but also on the crosslinking density and the shape of the polymer structures (Tobita and Hamielec 1992).…”

Section: Fundamental Principles Of Polymer Gel Dosimetrymentioning

confidence: 99%

Polymer gel dosimetry

et al. 2010

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Polymer gel dosimeters are fabricated from radiation sensitive chemicals which, upon irradiation, polymerize as a function of the absorbed radiation dose. These gel dosimeters, with the capacity to uniquely record the radiation dose distribution in three-dimensions (3D), have specific advantages when compared to one-dimensional dosimeters, such as ion chambers, and two-dimensional dosimeters, such as film. These advantages are particularly significant in dosimetry situations where steep dose gradients exist such as in intensity-modulated radiation therapy (IMRT) and stereotactic radiosurgery. Polymer gel dosimeters also have specific advantages for brachytherapy dosimetry. Potential dosimetry applications include those for low-energy x-rays, high-linear energy transfer (LET) and proton therapy, radionuclide and boron capture neutron therapy dosimetries. These 3D dosimeters are radiologically soft-tissue equivalent with properties that may be modified depending on the application. The 3D radiation dose distribution in polymer gel dosimeters may be imaged using magnetic resonance imaging (MRI), optical-computerized tomography (optical-CT), x-ray CT or ultrasound. The fundamental science underpinning polymer gel dosimetry is reviewed along with the various evaluation techniques. Clinical dosimetry applications of polymer gel dosimetry are also presented.

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Section: Fundamental Principles Of Polymer Gel Dosimetrymentioning

confidence: 99%

Polymer gel dosimetry

et al. 2010

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“…It fits well with the three stages in the crosslinking copolymerization of AM/BAM: pre-gel reactions, gelation, and postgel reactions. [26] Effect of duration of Swelling on the Immobilization It takes time for the penetrant transport of methanol and diffusion of monomers in semicrystalline PET. With longer swelling time, more monomers could be uptaken and take part in the polymerization.…”

Section: Effect Of Irradiation Duration On the Immobolizationmentioning

confidence: 99%

Surface Interpenetrating Networks of Poly(ethylene terephthalate) and Polyamides for Effective Biocidal Properties

Liu

Zhao

Rudenja

2010

Macro Chemistry & Physics

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Poly(ethylene terephthalate) (PET) fabrics were modified by diffusing vinyl amide monomers, divinyl crosslinker N,N′‐methylenebisacrylamide (MBA) and photoinitiator benzophenone (BP) into the surface of the PET substrate, which was swollen in a mutual solvent. Subsequent in situ photo‐polymerization resulted in the stable entrapment of the polyamides within the surface of the PET. The PET/polyamide systems produced by this technique were physically inseparable except by melting or dissolving PET. It is referred to as a sequential interpenetrating polymer network (IPN): thermoplastic semi‐IPN. Analyses of these materials by infrared spectroscopy, X‐ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) confirmed the successful incorporation of polyamide and revealed that the polyamide is also uniformly distributed along the PET yarns. Modulated differential scanning calorimetry (MDSC) indicated a certain degree of phase‐mixed structure between PET and polyacrylamide, despite the thermodynamic incompatibility of two polymers, which could be induced to separate upon heating above the melting point of PET. These materials were stable upon Soxhlet extraction with distilled water for 72 h, and also with methanol for 24 more hours. After being converted to N‐halamine via chlorine bleaching, these materials can bring 100% reduction of the hospital acquired methicillin‐resistant Staphylococcus aureus within 10 min contact.magnified image

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“…The gelation mechanism has been studied extensively [10,13,14] and remains an active research area [6,9]. Polymerization begins with the reaction between radicals and monomers, forming growing centers to which monomers diffuse, thus forming clusters that are linked by PA chains to form a connected network (percolating cluster).…”

Section: Introductionmentioning

confidence: 99%

Universal aspects of hydrogel gelation kinetics, percolation and viscoelasticity from PA-hydrogel rheology

Adibnia

Hill

2016

Journal of Rheology

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Polyacrylamide (PA) hydrogels have been studied extensively, but fundamental aspects of their gelation kinetics, percolation dynamics, and viscoelasticity are still not well understood. This paper focuses on the rheology of PA hydrogels having unusually low monomer concentrations. These furnish loss tangents that span four orders of magnitude when varying the crosslinker concentration [...] Close correspondence of the exponents with those of Adam et al. for the radical copolymerization of a di↵erent material supports the long-standing hypothesis that dynamics at the gel point are universal for a prescribed gelation mechanism

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Polyacrylamide gels. Process of network formation

Cited by 55 publications

References 24 publications

Polymer gel dosimetry

Polymer gel dosimetry

Surface Interpenetrating Networks of Poly(ethylene terephthalate) and Polyamides for Effective Biocidal Properties

Universal aspects of hydrogel gelation kinetics, percolation and viscoelasticity from PA-hydrogel rheology

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