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Publication Metadata only Effect of Ionic and Nonionic Carriers in Electrical Field-Flow Fractionation(2016-02-02) Mathuros Ornthai; Atitaya Siripinyanond; Bruce K. Gale; Mahidol University; Huachiew Chalermprakiet University; University of Utahmaterials and biological materials typically have high ionic strengths and high osmotic concentrations, we explore the effect of concentration for phosphate buffered saline (PBS), a typical ionic medium for biological samples, and for two nonionic materials...© 2015 American Chemical Society. A major limitation of electrical field-flow fractionation (ElFFF) is the polarization of the electrodes that occurs when using an ionic carrier liquid. As there is great interest in using ElFFF with biologicalPublication Metadata only Use of nitrogen-doped amorphous carbon nanodots (N-CNDs) as a fluorometric paper-based sensor: A new approach for sensitive determination of lead(ii) at a trace level in highly ionic matrices(2021-08-28) Siwaluck Boonruang; Puttaraksa Naksen; Wipark Anutrasakda; Kantapat Chansaenpak; Vinich Promarak; Rattaporn Saenmuangchin; Chutima Phechkrajang; Purim Jarujamrus; Vidyasirimedhi Institute of Science and Technology; Ubon Ratchathani University; Chulalongkorn University; Thailand National Nanotechnology Center; Mahidol UniversityThis work reports a facile synthesis of nitrogen-doped amorphous carbon nanodots (N-CNDs) and their use as a fluorometric paper-based sensor for the determination of Pb2+ at a low concentration. Both solution-based and paper-based systems were...+ concentration.Publication Metadata only Comparison of DNA, aminoethylglycyl PNA and pyrrolidinyl PNA as probes for detection of DNA hybridization using surface plasmon resonance technique(2010-01-15) Cheeraporn Ananthanawat; Tirayut Vilaivan; Voravee P. Hoven; Xiaodi Su; Chulalongkorn University; Mahidol University; Institute of Materials Research and Engineering, A-Star, Singaporeof SPR on various important aspects. These include the effect of ionic strength on hybridization efficiency, the specificity to detect the mismatch(es) in target DNAs, the direction of binding (parallel or antiparallel) to target DNAs, and the effect... of target DNA concentration on hybridization efficiency. Results indicated that the immobilized acpcPNA probe possesses distinct hybridization properties relative to aegPNA (and/or DNA) counterparts, including a higher single-base mismatch sensitivityPublication Metadata only Observation of salt-induced β-lactoglobulin aggregation using sedimentation field-flow fractionation(2006-11-01) Sudarat Saeseaw; Juwadee Shiowatana; Atitaya Siripinyanond; Mahidol University-lactoglobulin concentrations, as well as contact time, on the aggregation of β-lactoglobulin were examined. All factors exhibited a combined effect on the size of aggregates, whereby larger aggregates were obtained at increased concentrations of Zn2+and β...-lactoglobulin. At fixed concentrations of 2% (w/v) β-lactoglobulin and 10 mM Zn2+, the particle size of the aggregates increased from 0.19 μm (at 15 min) to 0.38 μm (at 2880 min). Further, a hyphenated technique of SdFFF and inductively coupled plasma-opticalPublication Metadata only Sphere-to-rod transition of non-surface-active amphiphilic diblock copolymer micelles: A small-angle neutron scattering study(2007-08-28) Ploysai Kaewsaiha; Kozo Matsumoto; Hideki Matsuoka; Kyoto University; Mahidol University; Kindai University.; Matsumoto, K.; Matsuoka, H. Langmuir 2005, 21, 9938) that this strongly ionic amphiphilic diblock copolymer shows almost no surface activity but forms micelles in water. In this study, the size, shape, and internal structures of the micelles formed.... Furthermore, the addition of salt at high concentration also induced the sphere-to-rod transition in micellar shape as a result of the shielding effect of electrostatic repulsion. The corona thickness was almost constant up to the critical salt concentrationPublication Metadata only Prevulcanisation of skim latex: Morphology and its use in natural rubber based composite material(2005-12-01) Umaporn Paiphansiri; Pramuan Tangboriboonrat; Mahidol UniversityThe prevulcanisation of skim latex, a by-product of field natural rubber (NR) latex concentrated by centrifugation, using sulphur and peroxide systems was investigated. Compared to the peroxide prevulcanisation, the lower swelling ratio of film...) (PEO) moieties of a non-ionic surfactant (Nonidet) adsorbed on small SPVS particles and the indigenous surfactant (protein-lipid) on a large NR particle. The value of zeta potential of heterocoagulated particle and the better oil resistance of filmsPublication Metadata only Adsorption of polystyrene-poly(4-vinylpyridine) diblock copolymer on the assembled latex film(2005-07-01) S. Sangribsub; P. Tangboriboonrat; T. Pith; G. Decher; Mahidol University; Institut Charles Sadroncopolymer (PS-PVPy) dissolved in tetrahydrofuran, the contact angle value indicated that the PS-PVPy could be adsorbed on the film to provide PS block at the outermost layer. The selective solvent, block length of PVPy, latex concentration, immersion time... and ionic strength of aqueous solution of poly(allylamine hydrochloride) (PAH) previously adsorbed on the substrate showed influence on the adsorption of the block copolymer and, hence, the contact angle of the film. © 2005 Elsevier Ltd. All right reserved.Item Metadata only Observing zinc oxide nanoparticles suspension stability in various media by using single particle inductively coupled plasma mass spectrometry (SP-ICP-MS)(2024-01-01) Pusuwan P.; Siripinyanond A.; Pusuwan P.; Mahidol Universitythe method allows to detect specific nanoparticles at very low concentration. The settling experiment of ZnO nanoparticles suspended in various media, including deionized water, non-ionic, cationic and anionic surfactants, was carried out to study size... the sample at various times and vertical distances. Then, the collected samples were diluted and analyzed by SP-ICP-MS to obtain the information on particle size distribution and the particle number concentration. The size and morphology of the ZnPublication Metadata only Surface nanostructure of Hevea brasiliensis natural rubber latex particles(2011-10-20) Kanjanee Nawamawat; Jitladda T. Sakdapipanich; Chee C. Ho; Yujie Ma; Jing Song; Julius G. Vancso; Mahidol University; Universiti Tunku Abdul Rahman; MESA Institute for NanotechnologyNatural rubber (NR) from the Hevea brasiliensis tree is the main commercial feedstock for rubber and latex dipping industries. NR latex particles in a matured commercial latex concentrate are stabilized by charged groups derived from proteins, long...-chain fatty acid soaps and polypeptides adsorbed on the particle surface. The colloidal stability of the latex is extremely sensitive to pH as well as to the ionic environment of the dispersing medium. Previous work on particle microelectrophoresis hasItem Metadata only Use of single particle inductively coupled plasma mass spectrometry for understanding the formation of bimetallic nanoparticles(2022-01-01) Heetpat N.; Sumranjit J.; Siripinyanond A.; Mahidol UniversityNPs to dissolved ionic silver with the formation of AuNPs covering the remaining AgNPs, producing a hole inside the core nanoparticles. Another protocol was to prepare AgAu alloy nanoparticles. SP-ICP-MS was used in combination with FlFFF to provide information.... With prior FlFFF, monomodal distributions were observed by SP-ICP-MS, which allow the use of particle concentration and size to estimate the mass concentration of elements on the fractionated bimetallic nanoparticles. This study illustrates the potential use