Synthesis,structural characterization,and photoluminescence properties of TTB‐type PbTa2O6:Eu3+ phosphor

Undoped and Eu³⁺‐doped tetragonal tungsten bronze (TTB) PbTa₂O₆ phosphors were synthesized by using solid‐state reaction method. Synthesized samples were characterized by XRD, SEM‐EDS, and photoluminescence analyses. XRD results revealed TTB‐type crystal structure with single phase up to 10 mol% Eu³⁺ doping concentration. In SEM‐EDS analyses, elemental composition of Pb decreased with the increasing concentration of Eu³⁺. Emissions at the excitation wavelength of 398.5 nm were observed at 593.2 and 618.8 nm due to ⁵D₀→⁷F₁ transitions and ⁵D₀→⁷F₂ transitions, respectively. Emission increased with the increasing Eu³⁺ doping concentration up to 10 mol% and not observed concentration quenching.     

Characterization and photoluminescence properties of diglycidyl methacrylic resin doped with the Eu3+–β‐diketonate complex

Triaquatris(acetyl acetonate)europium(III) [Eu(acac)₃] at 1, 5, 10, and 15% was doped in diglycidyl methacrylic (DGMA) resin, and their luminescent properties in the solid state are reported. These systems were characterized with elemental analysis, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and Fourier transform infrared spectroscopy. On the basis of TGA data, the thermal stability of the DGMA/Eu(acac)₃x% system was similar to that of the polymer, except at the highest concentration (15%). The DSC results indicated that the new systems were chemically stable and underwent the cure process before decomposition. The emission spectra of the Eu³⁺/acetyl acetonate complex doped in DGMA, recorded at 298 and 77 K, exhibited the characteristic bands arising from the ⁵D₀→⁷F_J transitions (J = 0–4). The luminescence intensity decreased with an increasing precursor concentration in the doped polymer. The system doped at a low concentration (1% Eu³⁺ complex) presented more luminescence efficiency than those doped at 5, 10, and 15%. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 406–412, 2006     

Enhancement of the luminescent intensity of the novel system containing Eu3+‐β‐diketonate complex doped in the epoxy resin

Photoluminescent properties of the europium tris(thenoyltrifluoroacetonate) dihydrate [Eu(TTA)₃(H₂O)₂] incorporated in epoxy resin in the solid state are reported. The polymeric Eu³⁺ complex and the precursor compound were characterized by elemental analysis, thermogravimetry (TG), differential scanning calorimetry (DSC), infrared spectroscopy, nuclear magnetic resonance (NMR), and electronic spectroscopy. Due to efficient energy transfer from the polymer to the rare earth ion, the polymer phosphorescence intensity was observed to decrease with an increase of the Eu³⁺ ion concentration. High values of the Ω₂ intensity parameter were obtained, reflecting the hypersensitive character of the ⁵D₀ → ⁷F₂ transition and indicating that the Eu³⁺ ions are in a highly polarizable chemical environment. This is consistent with systems containing epoxy resin that generally show a higher value for the Ω₄ parameter as a consequence of the difference in the basicity of the oxygen donor from the polymer. Lifetime measurement (τ = 0.442 ms) suggests that the Eu³⁺ luminescence has a higher efficiency than in the case of hydrated compound (τ = 0.260 ms). The emission quantum efficiency shows higher luminescence for the polymer containing 1% of Eu³⁺‐β‐diketonate complex. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2716–2726, 2002     

Gd3Al5O12：Eu^3＋柠檬酸盐硝酸盐燃烧法合成及其发光性能研究

采用柠檬酸盐硝酸盐燃烧法，在较低的温度（900℃）下成功地合成单一晶相Gd3Al5O12：Eu^3＋发光粉体，紫外激发荧光光谱分析表明，粉体615m和593m荧光发射源于Eu^3＋的^5D0-^7F2和^5D0-^7F1跃迁．该方法中各工艺条件（如pH值、柠檬酸／金属离子比、煅烧温度）对Gd3Al5O12：Eu^3＋发光性能均有影响，通过试验得出了获得最佳发光性能荧光粉体的工艺参数．     

Synthesis and photoluminescence of novel blue-emitting phosphor of Eu2+-activated fluoroborate BaGaBO3F2

Pure and Eu²⁺-activated fluoroborate BaGaBO₃F₂ was prepared using high-temperature solid-state reaction. BaGaBO₃F₂ is a wide band semiconductor with the indirect transition characteristic. The excitation and luminescence spectra of the phosphor were measured, and it was found that Eu²⁺-activated BaGaBO₃F₂ exhibits a bright blue color under ultraviolet (UV) light. The narrow emission band peaked at 425 nm is attributed to the transitions of 4f⁶5d→4f⁷(⁸S_7/2), and the Stokes shift estimated for this phosphor sample is 3140 cm⁻¹. The lifetime of the luminescence is also reported. The absolute quantum efficiency (QE) of the phosphor was evaluated, and it was found that the absolute QE decreases with increasing Eu²⁺ concentration. The phosphor shows an excellent quantum efficiency of 72.5% and a high thermal activation energy of 0.342 eV. The study concludes that Eu²⁺-doped BaGaBO₃F₂ phosphor has promising luminescence application abilities and can be used as a blue-emitting phosphor in a variety of applications.     

Synthesis and photoluminescence properties of Eu2+/Eu3+ or Ce3+/Eu3+ co-doped Sr5(BO3)3F compounds

The synthesis and photo-luminescence properties of Eu²⁺/Eu³⁺ or Ce³⁺/Eu³⁺ co-doped Sr₅(BO₃)₃F compounds are reported. Using the Sr₅(BO₃)₃F as the host, through the solid state reaction under the reductive atmosphere, Eu²⁺/Eu³⁺ and Ce³⁺/Eu³⁺co-doped samples were prepared. These compounds exhibit good photo-luminescence properties. Under the excitation of 376 nm, an unusual red orange emission coming from the Eu²⁺ ions can be obtained in Eu ions doped Sr₅(BO₃)₃F, which exhibits a broadband emission in the range of 450–800 nm with the peak at around 600 nm. At the same time, the characteristic f-f excitation and emission of Eu³⁺ can improve and adjust the Eu²⁺ emission in Eu³⁺/Eu²⁺ codoped Sr₅(BO₃)₃F. In addition, the adjustable luminescence properties from blue to white of Sr₅(BO₃)₃F:Ce³⁺, Eu³⁺ are investigated. The energy transfer behavior from Ce³⁺ to Eu³⁺ was confirmed. In the spectra of the co-doped samples, we can hardly observe the characteristic peak of Eu²⁺, because Ce⁴⁺ can oxidize Eu²⁺ to Eu³⁺, and Ce⁴⁺ itself is reduced to Ce³⁺. The CIE coordinates from (0.2758, 0.2420) to (0.3857, 0.3015) show Sr₅(BO₃)₃F:3%Ce³⁺, x%Eu³⁺ (x = 1,3,5,7,9) are in the white light emission region. All results demonstrate that the Sr₅(BO₃)₃F:Eu³⁺/Eu²⁺ and Sr₅(BO₃)₃F:Ce³⁺/Eu³⁺ phosphors have good application prospects for LED plant growth and white LED, respectively. The bond energy method was used to explain the reason why the Eu²⁺/Eu³⁺ ion instead of only Eu²⁺ and Ce³⁺/Eu³⁺ instead of Ce³⁺/Eu³⁺/Eu²⁺ can exist in the host Sr₅(BO₃)₃F. The theoretical analysis agree well with the experimental result.     

Controllable hydrothermal synthesis and photoluminescence properties of CaGd2(WO4)4:Eu3+ red-emitting phosphor

CaGd₂(WO₄)₄:Eu³⁺ phosphors with controllable morphology were synthesized via the hydrothermal method. The influences of pH value, reaction time and Eu³⁺ concentration on the crystal structure, morphology, and photoluminescence properties of CaGd₂(WO₄)₄:Eu³⁺ were studied. The pure tetragonal structure CaGd₂(WO₄)₄ is obtained when the pH value is 8 and 9. Furthermore, by altering the pH value of the reaction solution, the morphologies of the CaGd₂(WO₄)₄:Eu³⁺ phosphors evolve from spindle-shaped grains to tetragonal plate-like grains and finally to aggregated bulk particles. Under the 394 nm excitation, the phosphors display a bright red emission corresponding to the characteristic 4f-4f transitions of Eu³⁺, and the intensity of emission peaks depends mainly on the pH value, the reaction time, and the Eu³⁺ concentration. The optimum photoluminescence performance is achieved for CaGd_2-x(WO₄)₄:xEu³⁺ (x = 1) phosphor synthesized at pH = 8 under the reaction time of 16 h. Finally, the thermal stability of the phosphors is analyzed at different ambient temperatures.     

SrAl2O4:Eu2+,Dy3+,Pr3+纳米长余辉发光材料的制备与表征

以硝酸盐和尿素为基质,采用燃烧法在650℃合成了SrAl2O4:Eu2+,Dy3+,Pr3+长余辉发光粉体.研究了样品的晶体结构、晶粒大小及发光性能.结果表明:Eu2+,Dy3+,Pr3+共掺杂的磷光体没有改变铝酸锶的晶体结构,平均晶粒尺寸为41.5nm;激发和发射光谱分别为360nm和515nm的宽带谱,与SrAl2...     

A novel dazzling Eu3+‐doped whitlockite‐type phosphate red‐emitting phosphor for white light‐emitting diodes

A series of novel red‐emitting Ca₈ZnLa_1?xEu_x(PO₄)₇ phosphors were successfully synthesized using the high‐temperature solid‐state reaction method. The crystal structure, photoluminescence spectra, thermal stability, and quantum efficiency of the phosphors were investigated as a function of Eu³⁺ concentration. Detailed analysis of their structural properties revealed that all the phosphors could be assigned as whitlockite‐type β‐Ca₃(PO₄)₂ structures. Both the PL emission spectra and decay curves suggest that emission intensity is largely dependent on Eu³⁺ concentration, with no quenching as the Eu³⁺ concentration approaches 100%. A dominant red emission band centered at 611 nm indicates that Eu³⁺ occupies a low symmetry sites within the Ca₈ZnLa(PO₄)₇ host lattice, which was confirm by Judd‐Ofelt theory. Ca₈ZnLa_1?xEu_x(PO₄)₇ phosphors exhibited good color coordinates (0.6516, 0.3480), high color purity (~96.3%), and high quantum efficiency (~78%). Temperature‐dependent emission spectra showed that the phosphors possessed good thermal stability. A white light‐emitting diode (LED) device were fabricated by integrating a mixture of obtained phosphors, commercial green‐emitting and blue‐emitting phosphors into a near‐ultraviolet LED chip. The fabricated white LED device emits glaring white light with high color rendering index (83.9) and proper correlated color temperature (5570 K). These results demonstrate that the Ca₈ZnLa_1?xEu_x(PO₄)₇ phosphors are a promising candidate for solid‐state lighting.     

Synthesis,characterization, and thermodynamic properties of poly(3‐mesityl‐2‐hydroxypropyl methacrylate)

Poly(3‐mesityl‐2‐hydroxypropyl methacrylate) (PMHPMA) was synthesized in a 1,4‐dioxane solution with 2,2′‐azobisisobutyronitrile as the initiator at 60°C. The homopolymer and its monomer were characterized with ¹H‐ and ¹³C‐NMR, Fourier transform infrared, differential scanning calorimetry, thermogravimetric analysis, size exclusion chromatography, and elemental analysis techniques. According to size exclusion chromatography analysis, the number‐average molecular weight, weight‐average molecular weight, and polydispersity index of PMHPMA were 65,864 g/mol, 215,375 g/mol, and 3.275, respectively. According to thermogravimetric analysis, the carbonaceous residue value of PMHPMA was 14% at 500°C. The values of the specific retention volume, adsorption enthalpy, sorption enthalpy, sorption free energy, sorption entropy, partial molar free energy, partial molar heat of mixing, weight fraction activity coefficient of solute probes at infinite dilution (Ω), and Flory–Huggins interaction parameter (χ) were calculated for the interactions of PMHPMA with selected alcohols and alkanes by the inverse gas chromatography method at various temperatures. According to Ω and χ, selected alcohols and alkanes were nonsolvents for PMHPMA at 423–453 K. Also, the solubility parameter of PMHPMA (δ₂) was found to be 24.24 and 26.33 (J/cm³)^0.5 from the slope and intercept of (δ/RT) ? χ/V₁ = (2δ₂/RT)δ₁ ? δ/RT at 443 K, respectively [where δ₁ is the solubility parameter of the probe, V₁ is the molar volume of the solute, T is the column temperature (K), and R is the universal gas constant]. The glass‐transition temperature of PMHPMA was found to be 386 and 385 K by inverse gas chromatography and differential scanning calorimetry techniques, respectively. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 101–109, 2006     

Structural and emission properties of Eu3+‐doped alkaline earth zinc‐phosphate glasses for white LED applications

Quaternary alkaline earth zinc‐phosphate glasses in molar composition (40 ? x)ZnO – 35P₂O₅ – 20RO – 5TiO₂ – xEu₂O₃ (where x=1 and R=Mg, Ca, Sr, and Ba) were prepared by melt quenching technique. These glasses were studied with respect to their thermal, structural, and photoluminescent properties. The maximum value of the glass transition temperature (T_g) was observed for BaO network modifier mixed glass and minimum was observed for MgO network modifier glass. All the glasses were found to be amorphous in nature. The FT‐IR suggested the glasses to be in pyrophosphate structure, which matches with the theoretical estimation of O/P atomic ratio and the maximum depolymerization was observed for glass mixed with BaO network modifier. The intense emission peak was observed at 613 nm (⁵D₀→⁷F₂) under excitation of 392 nm, which matches well with excitation of commercial n‐UV LED chips. The highest emission intensity and quantum efficiency was observed for the glass mixed with BaO network modifier. Based on these results, another set of glass samples was prepared with molar composition (40 ? x)ZnO – 35P₂O₅ – 20BaO – 5TiO₂ – xEu₂O₃ (x=3, 5, 7, and 9) to investigate the optimized emission intensity in these glasses. The glasses exhibited crystalline features along with amorphous nature and a drastic variation in asymmetric ratio at higher concentration (7 and 9 mol%) of Eu₂O₃. The color of emission also shifted from red to reddish orange with increase in the concentration of Eu₂O₃. These glasses are potential candidates to use as a red photoluminsecent component in the field of solid‐state lighting devices.     

GdF3∶Eu3+和NaGdF4∶Eu3+发光粉的可控合成与发光性质

采用聚乙烯吡咯烷酮(PVP)辅助水热法合成了GdF3∶Eu3+和NaGdF4∶Eu3+发光粉。利用X射线衍射(XRD)、扫描电子显微镜和荧光光谱对样品的结构、形貌和发光性能进行了研究。XRD分析表明:GdF3晶相到NaGdF4晶相的转换可以通过改变初始溶液pH值、PVP加入量和NaF与稀土离子(Gd3+和Eu3+)摩尔配比等合成条件实现。NaGdF4∶Eu3+发光粉的形貌受合成条件的影响。荧光光谱研究表明:GdF3∶Eu3+发光粉主发射峰位于593nm处,来自于Eu3+的5 D0→7 F1磁偶极跃迁;NaGdF4∶Eu3+发光粉主发射峰位于616nm,来自于Eu3+的5 D0→7 F2电偶极跃迁。2个样品中Gd3+与Eu3+离子之间存在较好的能量传递,而NaGdF4晶格更有利于2种离子的能量传递。     

Synthesis,characterization, and fluorescence properties of lanthanide complexes with the copolymers of 2‐butenedioic acid (z)‐mono‐ethyl ester and styrene

In this study, the luminescent macromolecular lanthanide complexes with the copolymers of styrene (St) and 2‐butenedioic acid (z)‐mono‐ethyl ester (BAME) have been synthesized, and an extensive characterization has been carried out by means of elemental analysis, FTIR, thermal analysis, and fluorescence determination. The results showed that the carboxylic groups on the chain of the polymers acted as bidentate ligands coordinated to lanthanide ions; and the coordination degree of ‐COO^?/Ln³⁺ in the macromolecular complexes was closely dependent on both the pH value of the solution and the molar ratio of St to BAME in the polymeric ligands. Thermal analysis manifested that the macromolecular complexes Ln‐PSt/BAME (Ln = Y, Sm, Dy, Eu, and Tb) were highly crosslinked and had high thermal stability and solvent resistance. The fluorescence determination indicated that Ln‐PSt/BAME complexes could emit characteristic fluorescence with comparatively high brightness and good monochromaticity, and the fluorescence intensity increased with an increasing of lanthanide content. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

NaBaY(BO3)2:Ce3+,Tb3+: A novel sharp green‐emitting phosphor used for WLED and FEDs

A new borate phosphor NaBaY(BO₃)₂: Ce³⁺, Tb³⁺ (NBY:Ce³⁺, Tb³⁺) was successfully synthesized under low temperature designed to put into application in the fields of ultraviolet (UV)‐excited light emitting diodes (LEDs) and field emission displays (FEDs). The structure distortion between Ce³⁺, Tb³⁺ single‐ and co‐doping NBY was discussed by X‐ray powder diffraction Rietveld refinement, high‐resolution transmission electron microscopy (HRTEM) and spectra. NBY: Ce³⁺, Tb³⁺ presents a wide absorption band ranging from 310 to 400 nm and efficient green emission (λ_max = 542 nm) with a full‐width at half‐maximum of 3.3 nm. The remarkable thermal stability has also been tested, indicating that the intensity at 200°C is still beyond 70% of the original intensity. In addition, a white LED device was manufactured by connecting a 370 nm UV chip with a blend of BaMaAl₁₀O₁₇: Eu²⁺ (BAM: Eu²⁺), NBY: Ce³⁺, Tb³⁺ and CaAlSiN₃: Eu²⁺. The color coordinate, correlated color temperature and color rendering index of the manufactured LED device were (0.335, 0.347), 5511 K and 80.16, respectively. Meanwhile, the cathodoluminescence (CL) spectra under the various conditions of probe currents and accelerating voltages were also analyzed. Through successive excitation of low‐voltage electron‐beam, the wonderful performances of degradation property and color stability were obtained. These results suggest that the green‐emitting NBY: Ce³⁺, Tb³⁺ phosphor has the prospect of becoming applications in white UV LEDs and FEDs.     

YVO4:Eu3+,Bi3+荧光粉的制备及荧光性能研究

用溶胶凝胶法在较低温度下制备了YVO4:Eu3+,Bi3+荧光粉,采用X射线衍射仪(XRD),扫描电子显微镜(SEM)及荧光分光光度计测试,研究了合成产物的结构、表面形貌,分析了在Eu3+含量一定的情况下掺杂Bi3+的浓度的变化对发光性能的影响.结果表明,溶胶凝胶法合成的YVO4:Eu3+,Bi3荧光粉为单相结构、粒径在1 μm左右、无团聚现象;Bi3+对Eu3+离子有敏化作用,在一定浓度下使荧光粉的发射强度增加.     

Distinct composite structure and properties of Eu(phen)2Cl3(H2O)2 in poly(methyl methacrylate) and polyvinylpyrrolidone

The luminescent europium complex Eu(phen)₂ Cl₃(H₂O)₂ (phen refers to 1,10‐phenanthroline) was doped in poly(methyl methacrylate) (PMMA) and polyvinylpyrrolidone (PVP), respectively. The formed composite systems with different molar ratios of C?O groups in polymers and Eu ions were characterized by X‐ray diffractometry (XRD), FTIR, and photoluminescent (PL) spectroscopy and lifetime measurement. The XRD diffractograms show that the composites of PMMA/Eu(phen)₂Cl₃(H₂O)₂ and PVP/Eu (phen)₂Cl₃(H₂O)₂ have crystalline and amorphous structures, respectively, arising from different interactions between the polymers and the complex, as revealed by FTIR spectra. This leads to distinct luminescent characteristics arising from the ⁵D₀→⁷F_J transitions of Eu(III) ion (J = 0–4). For the composite systems of PMMA/complex, the characteristics of the emission lines change with decreasing molar ratios of C?O/Eu and approach that of the pure complex; whereas the composite systems of PVP/complex have similar spectral features, regardless of the molar ratios, differing from that of the pure complex. The polymer matrices have a substantial influence on the structure and properties of the composites. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3524–3530, 2004     

Synthesis,structural and spectral properties of an ionic polyacetylene: Poly[N‐(5‐nitro‐2‐furanmethylene)‐2‐ethynylpyridinium bromide]

A new ionic polyacetylene was prepared by the activation polymerization of 2‐ethynylpyridine with 2‐(bromomethyl)‐5‐nitrofuran in high yield without any additional initiator or catalyst. This polymerization proceeded well in a homogeneous manner to give a high yield of the polymer (92%). The activated acetylenic triple bond of N‐(5‐nitro‐2‐furanmethylene)‐2‐ethynylpyridinium bromide, formed in the first quaternerization process, was found to be susceptible to linear polymerization. This polymer was completely soluble in such polar organic solvents as dimethylformamide, dimethyl sulfoxide, and N,N‐dimethylacetamide. The inherent viscosities of the resulting polymers were in the range 0.12–0.19 dL/g, and X‐ray diffraction analysis data indicated that this polymer was mostly amorphous. The polymer structure was characterized by various instrumental methods to have a polyacetylene backbone structure with the designed substituent. The photoluminescence peak was observed at 593 nm; this corresponded to a photon energy of 2.09 eV. The polymer exhibited irreversible electrochemical behaviors between the doping and undoping peaks. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Splitting upconversion emission and phonon‐assisted population inversion of Ba2Y(BO3)2Cl:Yb3+, Er3+ phosphor

Upconversion (UC) peak of ⁴S_3/2→⁴I_15/2 transition of Er³⁺ is close to that of ²H_11/2→⁴I_15/2 transition. The UC emission splitting of Er³⁺ caused by coordination fields of host results in that it is difficult to confirm which transitions (⁴S_3/2→⁴I_15/2 or ²H_11/2→⁴I_15/2) are responsible for the splitting UC emission peaks. In this work, the UC luminescence peaks located at 524, 540, 551, 565, 662, 677, and 683 nm were observed in the Ba₂Y(BO₃)₂Cl:Yb³⁺, Er³⁺ phosphor upon the 980 nm excitation. The 524 and 540 nm UC emissions intensity were increased, while the 551 and 565 nm UC emissions intensity were decreased with the temperature increasing from 323 to 573 K, which is attributed to the phonon‐assisted population inversion from the ⁴S_3/2 to ²H_11/2 level. The temperature dependence of UC emission spectra demonstrated that the 524 and 540 nm UC emissions are from ²H_11/2→⁴I_15/2 transition, and 551 and 565 nm UC emissions are from the ⁴S_3/2→⁴I_15/2 transition. Temperature sensing property was characterized by the UC intensity ratio of the ²H_11/2→⁴I_15/2 transition to ⁴S_3/2→⁴I_15/2 transition. The Ba₂Y(BO₃)₂Cl:Yb³⁺,Er³⁺ phosphor has potential application as the non‐contact temperature sensor.     

Coexistence mechanism of Eu2+/Eu3+ ions in YAl3(BO3)4: Crystal structure,luminescence property,and substitution defects

The coexistence mechanism of Eu²⁺ and Eu³⁺ ions in YAl₃(BO₃)₄ host under different reducing conditions is investigated and confirmed in great detail, which can be described by three aspects as following. First, Eu³⁺ is protected by the layered structure of YAl₃(BO₃)₄. Second, the number of the interstitial defects ((Al)_i^…,(Y)_i^…) increases with increasing Eu²⁺ to maintain the charge balance of the system. And these defects can capture free electrons which are used for the reduction of Eu³⁺. Finally, free holes become more and more with the number of nonequivalent substitution defects (Eu_Y') increasing, which make the 5d electrons of Eu²⁺easily escape to the conduction band and Eu²⁺ convert to Eu³⁺. This work will be of great significance to research coexistence of multiple valence ions in the structure of borate and defect motion with nonequivalent substitution.     

Synthesis and characterization of core‐shell SiO2 nanoparticles/poly(3‐aminophenylboronic acid) composites

SiO₂/Poly(3‐aminophenylboronic acid) (PAPBA) composites were synthesized under different experimental conditions, using ultrasonic irradiation method. Polymerization was carried out in the presence of sodium fluoride and D ‐fructose to anchor 3‐aminophenylboronic acid groups on to SiO₂ surface. The SiO₂/PAPBA nanocomposite prepared by NaF and D ‐fructose in the polymerization medium was found to show different morphology, electrical properties, thermal behavior and structural characterization in comparison to the nanocomposites prepared under other conditions. Ultrasonic irradiation minimizes the aggregation of nanosilica and promotes anchoring of PAPBA units over SiO₂ surface. The morphology of PAPBA/ SiO₂ nanocomposite was investigated by using transmission electron microscopy, UV‐visible spectroscopy; thermogravimetric analysis, Fourier transform infrared spectroscopy, and X‐ray diffraction analysis were used for characterization. Transmission electron microscope of the nanocomposites observation shows that SiO₂/PAPBA composite, prepared with D ‐fructose and NaF under ultrasonication has a core–shell morphology. The thermal and crystalline properties of core‐shell SiO₂/PAPBA nanocomposite was prepared via ultrasonication method is different from the SiO₂/PAPBA nanocomposite prepared via conventional stirring method, in which SiO₂ nanoparticles are submerged in PAPBA. Conductivity of the composite prepared via ultrasonication shows around 0.2 S/cm. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2743–2750, 2007