Low field Overhauser images of the formation process of a hydrogel

Barros, Wilson; de Souza, Ricardo E.; Engelsberg, M.; Golman, Klaes; Ardenkjær-Larsen, J. H.
January 2002
Applied Physics Letters;1/7/2002, Vol. 80 Issue 1, p160
Academic Journal
The gelation of sodium alginate by calcium ions is studied by proton-electron double resonance imaging in a magnetic field of only 16 mT using a newly developed free radical. The high sensitivity of the Overhauser enhancement to small variations in water mobility permits the detection of minute changes in gel composition. Spatial inhomogeneity and temporal evolution of this, and possibly other processes involving diffusion and chemical reaction, could be accurately monitored by this technique.


Related Articles

  • The steady state nuclear Overhauser effect revisited. Karthik, G. // Journal of Chemical Physics;3/15/1999, Vol. 110 Issue 11, p4992 

    Studies the steady state of a two spin system coupled to an isotropic environment and to each other through a dipolar interaction and under irradiation by a monochromatic, circularly polarized radio frequency field. Use of the steady state to describe nuclear Overhauser effect in liquids;...

  • Cross relaxation in magnetic resonance: An extension of the Solomon equations for a consistent description of saturation. Boulat, Benoit; Bodenhausen, Geoffrey // Journal of Chemical Physics;11/1/1992, Vol. 97 Issue 9, p6040 

    In magnetic resonance studies of cross relaxation or Overhauser effects by steady-state continuous irradiation, it is shown that the Solomon equations do not allow one to obtain a consistent picture of the expectation values of various magnetization components. The contradictions can be resolved...

  • Solution to nuclear Overhauser effect challenge. Meusinger, Reinhard // Analytical & Bioanalytical Chemistry;Oct2011, Vol. 400 Issue 9, p2683 

    The article announces that Albrecht Roscher of Génie Enzymatique et Cellulaire has won the nuclear Overhauser effect challenge.

  • The Overhauser model: Equilibrium fluctuation dynamics. Broidioi, Marino; Nachtergaele, Bruno; Verbeure, André // Journal of Mathematical Physics;Oct91, Vol. 32 Issue 10, p2929 

    A Goldstone-type theorem is derived to reveal the nature of the spontaneous symmetry breaking occurring in the Overhauser model. Explicit expressions for the equilibrium states of the model are calculated. The fluctuations of the fields satisfy a central limit theorem. The limit is a new set of...

  • Changes in ultraweak luminescence from living fish induced by three chemicals. Yingyan, Wang; Yuqin, Ma; Da, Li; Shenxun, Li; Yujing, Zhang; Xueling, Song // Bulletin of Environmental Contamination & Toxicology;Mar1991, Vol. 46 Issue 3, p456 

    The article presents a study on the effect of uranium dioxide (UO2), sodium azide (NaN) and cyclophosphamide in the ultraweak luminescence of a fish. It mentions adult zebra fish which was used in the study and its luminescence was measured through high sensitive single-photon counting system...

  • Synthesis and characterization of high performance superabsorbent hydrogels using [bis2-(methacryloyloxy)ethyl] phosphate as crosslinker. Gonçalves, A. A. L.; Fonseca, A. C.; Fabela, I. G. P.; Coelho, J. F. J.; Serra, A. C. // Express Polymer Letters;2016, Vol. 10 Issue 3, p248 

    Various superabsorbent polymers (SAPs) were synthesized by free radical copolymerization at 70°C using acrylic acid (AA), potassium acrylate (KA), N-isopropyl acrylamide (NIPAM) and sulfopropyl methacrylate potassium salt (SPM) as monomers, bis[2-(methacryloyloxy)ethyl] phosphate (BMEP) as...

  • Synthesis and Characterization of Magnetic Fe3O4/PAAm/LMSH Nanocomposite Hydrogel. Shuqiong Ma; Haihui Bai; Ran Jin; Qingsong Zhang; Xiaonan Zheng; Hengshui Zhang // Materials Science Forum;2016, Vol. 848, p49 

    Based on the preparation of polyacrylamide/clays lithium magnesium silicate hydrate (PAAm/LMSH, abbreviated as AP) nanocomposite hydrogel by in-situ free radical polymerization, Fe3O4 nano particles were introduced by chemical co-precipitation method, to form magnetic Fe3O4/PAAm/LMSH...

  • Polydopamine Nanoparticle for Poly(N-isopropylacrylamide)-based Nanocomposite Hydrogel with Good Free-radical-scavenging Property. Shuqiang Xiong; Yan Wang; Jing Zhu; Zuming Hu; Junrong Yu // Materials Science Forum;2016, Vol. 848, p94 

    Nanocomposite hydrogels (NC gels) consisting of poly(N-Isopropyl acrylamide) (pNIPAM)/polydopamine nanoparticles (PDAPs) were prepared by in-situ-free-radical polymerization of N-isopropyl acrylamide in the presence of modified PDAP in aqueous solution. The composition of the NC gels could be...

  • Biodegradable Chitosan Hydrogels for In Vitro Drug Release Studies of 5-Flurouracil an Anticancer Drug. Kokkarachedu Varaprasad; Vimala, K.; Sakey Ravindra; Narayana Reddy, N.; Siva Mohana Reddy, G.; Mohana Raju, K. // Journal of Polymers & the Environment;Jun2012, Vol. 20 Issue 2, p573 

    Novel semi-interpenetrating network (semi-IPN) hydrogels based on biodegradable chitosan and poly( N-isopropylacrylamide-co-2-acrylamido-2-methyl-1-propanesulfonic acid) were prepared by free radical addition polymerization. Fourier transform infrared spectra and scanning electron microscopy...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics