Mech Time Depend Mater — Part II. Rheology and mechanical performance. J Polym Res 19 :1—9. CAS Google Scholar. Macromol Symp — Download references. Chirag B. Agostino 1, , Camerino, MC, Italy. You can also search for this author in PubMed Google Scholar. Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. Reprints and Permissions. Godiya, C. Download citation.
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Chavarria, D. Paul, Polymer 45 , p. Wang, T. Pinnavaia, Chem Matter 10 , p. Hu, S. Wang, Z. Ling, Y. Zhuang, Z. Chen, W. Fan, Macromol Mater Eng , p. Into Fluorescence microscopy imaging of particle uptake in cells. A white slurry was obtained after 5 min, the solution organoclay in serum-free media 1 mg mL 1 was added to each well. To observe the morphology sizes, from 50 nm to micron size, which is typical of a terrace- of the exfoliated sheets of the as-prepared Mg-organoclay, 5 mg of like layered structure Fig.
EDX analysis showed that the Mg-organoclay was dispersed in DI water by 5 min sonication, composition, based on weight, of the Mg-organoclay was Mg dropped onto the clean surface of a glass substrate and air-dried. SEM In addition, 0. Each spec- 5.
The stacked exfoliated Mg-organoclay sheets of 4 cm 1, was collected from to cm 1. The absorption spectra of the Mg-organoclay and showed a range of micro-scale organic building blocks FITC-organoclay were investigated in ethanol solvent by UV—Vis Fig. However, the degree of exfoliation of Mg- SLM; AMINCO using a Xe arc lamp light source and 4 nm organoclay depended on drying sample conditions or the band pass excitation and emission monochromators. TEM images of the clay structure showed the to correct the time- and wavelength-dependent variation in the Xe light source.
The lifetime of the FITC-organoclay was measured by time- presence of exfoliated sheets containing nanoparticles, 30— Figure 1. SEM image of powder Mg-organoclay a , exfoliated stacked sheets of Mg-organoclay in DI water b , whose concentration was 2. Inset shows the EDX of rectangular selected area of a , Pt is surface-coating material. Figure 3. Photochemistry and Photobiology, , 86 Figure 4. We intensity of FITC, at nm, was redshifted by 50 nm in found that 0. Figure 3b shows a weaken- ing of the CH2 mode cm 1 due to the formation of covalent bonds at the primary amines of Mg-organoclay 12,13, As a result, the neighboring CH2 became more rigid.
This observation revealed that the basic unit of the structural Mg-organoclay was conserved, which agreed with observations from SEM Figure 5. Comparison ethanol. As shown in Fig. In contrast, FTIC-organoclay showed a different photoreaction pattern. This effect resulted from an increase in the dispersion of clay nanoparticles, implying that FITC-organo- clay in ethanol showed increased exfoliation upon irradiation.
As the irradiation time increased, photobleaching was ob- served Fig. Figure 6. Fluorescence solid lines and excitation dotted lines spectra of a FITC 3. The excitation and emission wavelength was and nm, respectively.
Table 1. Lifetime values s in nanoseconds As shown in the scheme, FITC-organoclay was synthesized by the covalent coupling of aminopropyl groups on the Mg-organoclay to the isocyanate group of FTIC via thiourea linkage.
FITC molecules randomly bound to the terminal amine groups of Mg-organoclay on both sides of the clay nanoparticles Fluores- cence lifetime data revealed that FITC molecules were characterized by two exponential decay values 0. As shown in Table 1, pure FITC showed a single decay component with one lifetime, indicating a homogeneous structure and microenvironment. This is probably due to the room at room temperature, respectively. The cause of the shortened lifetime in the FITC-organoclay structure has not yet been elucidated.
This observation contrasts with the lifetime extension observed for FITC conjugation to silica nanoparticles, which was attributed to a stabilization effect of the core shell structure The optical properties, particularly the time-dependent photobleaching of FITC-organoclay, suggest a dominant reversible photoinduced isomerization as a result of either photoirradiation or protection from photodegradation Fig.
More interestingly, a hyperchromic effect was observed for FITC-organoclay in ethanol but not in aqueous Figure With increasing irradiation time, photobleaching cells. Dosage is 1 mg mL 1. The two emission concentration.
The FITC-organoclay consists of clusters cellular uptake under the same conditions data not shown. The energy gap between the highest Previous studies of FITC labeling have discussed a variety of occupied molecular orbital HOMO and the LUMO may be particle labeling schemes, including the labeling of silica reduced by interaction with the spins of the unoccupied Mg nanoparticles 19,24—27 ; however, the conjugation of FITC levels 3s and 3p orbitals.
This explanation is consistent with to Mg-organoclay has not been described previously. Therefore, we propose that excited FITC and characterized the physicochemical properties of the electrons may undergo charge-transfer to the Mg levels 3s and products. Wang, Y. Su, X. Zhang and W. Wu, Y. Chen, C. Yang and Y. Tsai to Mg-organoclay 29— B , — Payet, L. Ponton, L. Hervet, J. Grossiord and timescale of the internal conversion process. Macromolecules 41, — Burkett, S.
Press and S. Mann Synthesis, charac- intensity of nanoparticles, making them less suitable for terization, and reactivity of layered inorganic-organic nanocom- immunoassay applications.
The cellular uptake of FITC- posites based on tricoctahedral phyllosilicates. As shown in Mann, S. Davis, C. Boesel and L. B Occurrence Handle Santana, R. Barbosa, H. Ferreira, A. Oliveira, H. Araujo and M. Barbosa, A. Rodrigues, T.
Melo and E. Ito, Mater.
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