• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.248-248
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• 2012

인산염을 기초로 한 다양한 촉매 기질의 합성과 더불어, 촉매활성를 가지는 여러 가지 전이 금속을 이러한 기질에 도입한 다양한 이종상 촉매가 개발되어 왔다. 우리는 phosphoric acid 와 zirconyl chloride을 이용하여 간단한 방법으로 ${\alpha}$-zirconium phosphate (Zr(HPO4)2.H2O)을 합성하였다. Phosphoric acid의 농도 변화에 따른 crystallinity의 변화를 XRD를 통해 분석하였고, FE-SEM을 통하여 형태를 확인 하였다. 특히, 합성한 각각의 생성물을 다양한 종의 amine을 이용하여 intercalation 반응을 수행하였다. 이를 XRD, TEM을 통하여 결정 구조 변화를 확인 하였고, 더 나아가 잠재적 촉매로서의 응용성을 연구할 예정이다.

• Journal of Powder Materials
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• v.9 no.5
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• pp.336-340
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• 2002

The $\alpha$-zirconium phosphate particles as fine as 20 nm were fabricated through solution technique using $ZrOCl_2{\cdot}8H_2O$ and $H_3PO_4$ as precursors. Stability of $\alpha$-Zirconium phosphate could be ensured by adding excess phosphoric acid to a stoichiometric composition Instead of using reflux route that resulted in coarsening of particles due to an inevitably long aging. The excess phosphorous incorporated in the crystal could be successfully eliminated afterwards through careful washing. Moreover, heavily agglomerated particles are observed before washing, but fairly dispersed state is found out after washing treatment. Thus, it is found that dispersed state as well as phase stability is ensured through proper washing treatment.

• Proceedings of the Korean Ceranic Society Conference
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• 2002.10a
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• pp.51.2-51
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• 2002

• Proceedings of the Korean Ceranic Society Conference
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• 2002.10a
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• pp.69.2-69
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• 2002

• The Journal of Advanced Prosthodontics
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• v.16 no.3
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• pp.163-173
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• 2024

PURPOSE. This study assessed the effect of storage time on chemical structure of a single-bottle and a two-bottle experimental ceramic primer and micro-shear bond strength (µSBS) of composite to ceramic. MATERIALS AND METHODS. This study was conducted on 60 sintered zirconia and 60 feldspathic porcelain blocks. Half of the specimens (n = 30) were subjected to surface treatment with the single-bottle Clearfil ceramic primer (n = 15) and two-bottle experimental primer (n = 15) after 24 hours. The remaining half received the same surface treatments after 6 months storage in distilled water. Composite cylinders were bonded to the ceramics, and they were then subjected to µSBS test. Also, the primers underwent Fourier-transform infrared spectroscopy (FTIR) after 24 hours and 6 months to assess their chemical structure. Data were analyzed with 3-way ANOVA and adjusted Bonferroni test (alpha = 0.05). RESULTS. The µSBS of both ceramics significantly decreased at 6 months in one-bottle ceramic primer group (P = .001), but it was not significantly different from the two-bottle experimental primer group (P = .635). FTIR showed hydrolysis of single-bottle primer, cleavage of silane and 10-MDP bonds, and formation of siloxane bonds after 6 months. CONCLUSION. Six months of storage caused significant degradation of single-bottle ceramic primer, and consequently had an adverse effect on µSBS.

• The Journal of Korean Academy of Prosthodontics
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• v.53 no.4
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• pp.318-324
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• 2015

Purpose: This study compared shear bond strengths of five self-adhesive cements with phosphate monomer to zirconium oxide ceramic with and without airborn particle abrasion. Materials and methods: One hundred zirconia samples were air-abraded ($50{\mu}mAl_2O_3$). One hundred composite resin cylinders were fabricated. Composite cylinders were bonded to the zirconia samples with either Permacem 2.0 (P), $Clearfil^{TM}$ SA Luting (C), $Multilink^{(R)}$ Speed (M), $RelyX^{TM}$ U200 Automix (R), G-Cem $LinkAce^{TM}$ (G). All bonded specimens were stored in distilled water ($37^{\circ}C$) for 24 h and half of them were additionally aged by thermocycling ($5^{\circ}C$, $55^{\circ}C$, 5,000 times). The bonded specimens were loaded in shear force until fracture (1 mm/min) by using Universal Testing Machine (Model 4201, Instron Co, Canton, MA, USA). The failure sites were inspected under field-emission scanning electron microscopy. The data was analyzed with ANOVA, Tukey HSD post-hoc test and paired samples t-test ($\alpha$=.05). Results: Before and after thermocycling, $Multilink^{(R)}$ Speed (M) revealed higher shear-bond strength than the other cements. G-Cem $LinkAce^{TM}$ (G) showed significantly lower bond strengths after thermocycling than before treatment (P<.05), but the other groups were not significantly different (P>.05). Conclusion: Most self-adhesive cements with phosphate monomer showed high shear bond strength with zirconia ceramic and weren't influenced by thermocycling, so they seem to valuable to zirconia ceramic bonding.