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Influence of addition of [2-(methacryloyloxy)ethyl] trimethylammonium chloride to an experimental adhesiveAbstract: The aim of this study was to develop an experimental adhesive with addition of [2-(methacryloyloxy)ethyl]trimethylammonium chloride (METAC) and to evaluate its mechanical and biological properties and its in vitro antibacterial activity. An experimental adhesive resin was formulated with Bis-GMA, TEGDMA, and HEMA. The antibacterial monomer was added at concentrations of 1%, 2.5%, and 5% (METAC groups). A group without METAC addition was used as control. The experimental adhesives were evaluated as to their antibacterial potential against Streptococcus mutans, degree of conversion, and softening in ethanol for 2 hours. The data were analyzed by one-way ANOVA, Tukey's post-hoc test, and the paired Student's t-test (significance level of 0.05). METAC showed antibacterial activity against S. mutans at all concentrations (p < 0.05). There was no statistical difference across METAC groups (p > 0.05). The 1%, 2.5%, and 5% groups yielded the highest mean values for degree of conversion (p < 0.05). The 1% group did not differ from the control group (p > 0.05). There was no statistical difference in baseline microhardness values (p > 0.05) and microhardness values after immersion in ethanol were lower than at baseline for all groups (p < 0.05). There was no statistical difference in the reduction of Knoop hardness number (KHN) after immersion in ethanol for any of the groups (p > 0.05). The results of the present study indicate that METAC is a promising antibacterial agent when added to an adhesive system.

SfliO, capacitor material with indiffused BiZ03 was studied using SEM, ESCA combined with Ar+ ion-etching, and TEM equipped with EDX. The apparent thickness of a second-phase layer observed with SEM was found to be influenced by in-depth effects. ESCA and TEM results show that only a 10-to 100-nm thick layer of second phase is present between the S f f i 0 3 grains. In addition, it was found with TEM that the outer part of each grain contained Bi (at most 2 at.%), representing a diffusion layer. These results have implications for the boundary-layer model proposed to explain the dielectric proper ties.

315(9) and a varying A a over the entire temperature range. If necessary, the required corrections can easily be introduced into the algorithm for computing net strains.Equation (10) is empirical only. Although some relation between log 77 at T , and B is expected, it cannot be altogether a general relation covering many glass compositions and all the possible values ofB. Yet, laboratory experience has shown that Eq. (10) is a fair approximation for glass systems other than AA, BB, and CC glasses. A practical use of Eq. (10) could be in writing manufacturer's specifications for the effective thermal expansion of a glass suitable for sealing to a metal as a function of the seal cooling rate.

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An einem SrTiO3‐ Grenzschichtmaterial, in das Bi2O3 eindiffundiert ist, wird mit Hilfe der Rasterelektronenmikroskopie, der ESCA (kombiniert mit Artlonenätzung) sowie der Transmissionselektronenmikroskopie (ausgerüstet mit einem energiedispersiven Röntgen‐ Spektrometer) eine detaillierte Korngrenzenuntersuchung durchgeführt.