Novel energy-saving window coating based on F doped TiO2 nanocrystals with enhanced NIR shielding performance

To reduce the energy consumption of cooling in the hot summer days, searching for novel NIR shielding materials for buildings is of great value. In this report, monodispersed F doped TiO₂ nanocrystals with an average size of 8.6 nm were synthesized as novel solar shielding materials for energy-saving windows. All the products adopted an anatase TiO₂ structure. After doping of F ions, the morphology of TiO₂ was transformed from an irregular shape to a pseudospherical shape. The Raman shift and XPS depth analysis confirmed the successful doping of F⁻ ions into the lattice oxygen sites in the TiO₂ structure. The introduction of F⁻ ions generated free electrons and bulk Ti³⁺ in TiO₂ crystals, which activated a localized surface plasmon resonance (LSPR) absorption in the NIR region. Correspondingly, the NIR shielding performance of the TiO₂ films improved with increasing F doping amounts. The NIR shielding value of the films increased from 1.3% to 43.2% when the molar ratio of F to Ti increased from 0 to 0.3. The reason can be attributed to the enhanced NIR absorption induced by the increased electron concentration after doping of fluorine ions. The F–TiO₂ films showed superior visible transmittance (90.1–96.7%). Moreover, the F–TiO₂ films lowered the indoor temperature of the heat box by 5.3 °C in the thermal tests. Overall, the prepared F–TiO₂ nanocrystals show a great potential to be used for energy-saving windows.     

Preparation and Characterization of Copper Gallium Diselenide Thin Films from the Solgel‐Derived Precursors

A simple process for preparing CuGaSe₂ (CGS) absorber layers was developed in this study. The solgel‐derived Cu‐Ga‐O precursor paste with variable Ga³⁺/Cu²⁺ ratios was coated on glass substrates using a doctor‐blade technique. The precursor films were selenided with a selenium vapor at the temperature ranging from 250 to 550°C. The GIXRD patterns showed that single‐phase CuGaSe₂ through the whole films was obtained at a Ga³⁺/Cu²⁺ molar ratio of 1.5 on selenization at 450°C. The Raman measurements also indicated that the grown CuGaSe₂ thin films exhibited the chalcopyrite structure. The SEM images of the films reveal that with an increase in Ga/Cu ratio in the films, the amount of Cu₂Se particles on the surface of the film was reduced. The resistivity of the films was increased with the increase in Ga content in the films. The formation mechanism of CuGaSe₂ thin films was proposed based on the XRD and Raman measurements of the films. The binary copper selenides are formed first, and then these phases lead to the formation of CuGaSe₂.     

New Magneto‐Optical Film of Ce,Ga:GIG with High Performance

Ce³⁺‐doped Gd₃Fe₅O₁₂ (Ce:GIG) film has a good application prospect in the field of integrated optical device. In this article, Ce:GIG and Ce,Ga:GIG films were deposited onto the quartz glass substrate by using radio‐frequency magnetron sputtering technology. The crystal phase, surface morphology, magnetization, and magnetic circular dichroism properties of films were characterized by using the X‐ray powder diffraction, atomic force microscopy, vibrating sample magnetometer, and circular dichroism spectrometer. The results show that as‐prepared Ce,Ga:GIG films has a good quality and show an excellent magneto‐optical performance, and the doping of Ga³⁺ ion and the annealing process have significant effect on the magnetism and magneto‐optical performances. It is expected that Ce,Ga:GIG film with a moderate Ga³⁺‐doping content is a better candidate than Ce:GIG and Ce:YIG films for the next generation of integrated optical isolator and other magneto‐optical equipment.     

Preparation and characterization of PVC/CsxWO3 composite film with excellent near-infrared light shielding and high visible light transmission

Near-infrared (NIR) shielding is essential not only in the building and automobile glass films but also in achieving energy conservation. However, effectively shielding NIR and maintaining high transmittance in the visible light region have been great challenges in the past decade. Recently, hexagonal cesium tungsten bronze (Cs_xWO₃) nanoparticles have been widely studied due to the excellent transparency in the visible light region and strong heat-shielding ability in the NIR region. Herein, a design concept of transparent polyvinyl chloride (PVC)/Cs_xWO₃ composite film, as a heat insulation material for glasses, was proposed. To achieve this purpose, the PVC/Cs_xWO₃ composite film was prepared by incorporating Cs_xWO₃ slurry with better dispersion than traditional Cs_xWO₃ nanoparticles powder into a transparent PVC matrix. By the UV-Vis-NIR spectrophotometer characterization, the PVC/Cs_xWO₃ composite film containing 2.1 phr Cs_xWO₃ slurry displays high blocking of NIR (78%) and high transmittance of visible light (76%). In order to further understand the actual heat insulation effect from the PVC/Cs_xWO₃ composite films, the indoor sunlight simulation test and outdoor cooling experiment with solar illumination variations were carried out, which both showed heat insulation that is superior to the antimony tin oxide and indium tin oxide thin films prepared in our previous work. In addition, the mechanical property of PVC/Cs_xWO₃ composite films shows almost no change with the increase of Cs_xWO₃ slurry. The PVC/Cs_xWO₃ composite films simultaneously achieve excellent shielding of NIR and high transmittance of visible light, which makes it an ideal material to alleviate the current building energy consumption issues.     

Effect of weak reductant on properties of electroless copper polyacrylonitrile nanocomposites for electromagnetic interference shielding

In this work, the electroless copper method with different reductant compositions (NaHSO₃/Na₂ S₂O₃·5H₂O and Na₂S₂O₃·5H₂O) without sensitizing and activating, was used to deposit copper‐sulfide deposition on the polyacrylonitrile (PAN) surface for electromagnetic interference (EMI) shielding materials. The weak reductant, NaHSO₃, in the electroless copper method was used to control the phase of copper‐sulfide deposition. The Cu_x(x=1–1.8)S was deposited on the PAN (Cu_xS‐PAN) by reductant composition (NaHSO₃/Na₂S₂O₃·5H₂O) and the Cu_x(x=1–1.8)S deposition of Cu_xS‐PAN possesses three kinds of copper‐sulfide phases (CuS, Cu_1.75S and Cu_1.8S). However, the electroless copper with reductant was only Na₂S₂O₃·5H₂O (without weak reductant, NaHSO₃), the hexagonal CuS deposition was plated on the PAN (CuS‐PAN) and increased the EMI shielding effectiveness of CuS‐PAN composites about 10–15 dB. In this study, the best EMI SE of CuS‐PAN and Cu_xS‐PAN composites were about 27–30 dB and 15–17 dB respectively, as the cupric ion concentration was 0.24 M. The volume resistivity of CuS‐PAN composite was about 1000 times lower than that of Cu_xS‐PAN composite and lowest volume resistivity of CuS‐PAN composites was 0.012 Ω cm, as the cupric ion concentration was 0.24 M. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Alkali metal tungsten bronze-doped energy-saving glasses for near-infrared shielding applications

Tungsten bronze has attracted global attention for its applications in near-infrared (NIR)-shielding windows. Here, alkali metal tungsten bronze (M_xWO₃, M = one or two types of Li, Na, and K)-doped glasses are prepared by a simple melt-quenching method. Their structure and properties were characterized by XRD, Raman spectroscopy, XPS and UV–Vis–NIR spectrophotometry. The effects of M on their structure and the NIR shielding performance are investigated. The LiF sample has the best NIR shielding performance, but its visible transmittance is sacrificed due to its low quality. The glasses containing mixed Li⁺ and K⁺ cooperate to form a high-quality Li⁺/K⁺-codoped tungsten bronze, while the glasses containing mixed Li⁺ and Na⁺ compete for limited tungsten resources to form Li⁺- and Na⁺-doped tungsten bronzes separately. The research here is helpful for understanding the role of different alkali metal ions in bulk energy-saving glass and is hugely significant for the guidance of the future applications of energy-saving glass without films.     

Doping saturation in dye-sensitized solar cells based on ZnO:Ga nanostructured photoanodes

The origins of the performance of dye-sensitized solar cells based on ZnO:Ga nanostructured photoelectrodes, compared to analogous ZnO solar cells, were studied by means of impedance spectroscopy under illumination as a function of forward bias voltage. The film capacitance is governed by Ga doping. It can be assumed that the higher donor density of states of ZnO materials and, principally, ZnO:Ga-doped materials pin the Fermi level at a certain shallow energy level so that there is no photovoltage variation as a function of doping level. On the other hand, short circuit current is determined by the increasing roughness factor obtained at the higher doping levels while the lower fill factor values of DSCs based on ZnO:Ga, compared to analogous ZnO, were attributed to the higher ohmic resistive losses associated with the increasing photocurrent densities. In any case, the microstructure and morphological aspects were also considered as a possible origin of the low fill factor values. The estimated donor density level exceeds 10²¹ cm⁻³, indicating a high doping level in the semiconductor. As a consequence of the synthesis process of ZnO:Ga nanoparticles its size diminishes with the higher Ga contents producing an increase in the overall roughness factor of the films, and then a larger dye upload and short circuit current.     

Defect cluster engineering in ZnGa2−x(Mg/Ge)xO4:Cr3+ nanoparticles for remarkably improved NIR persistent luminescence

Recently, study on Cr³⁺-doped zinc gallate and zinc gallogermanate persistent phosphors has become a hot topic in persistent luminescence and bio imaging areas, because of their near infrared (NIR) emission and long afterglow. However, regulation of efficient traps and improvement of persistent luminescence through bottom-up design are the key challenge. Here, we recommend a new paradigm of chemical unit co-substitution with [Mg²⁺-Ge⁴⁺] substituting for [Ga³⁺-Ga³⁺] in ZnGa₂O₄, which contributes to the opposite charged and distorted octahedral defects of Mg_Ga′ and Ge_Ga ^· in pair around the Cr_N2 ions. The formed defect clusters of Mg_Ga′-Cr_N2-Ge_Ga ^· , which are closely related to the trap depth, can be accurately regulated through varying the doping content of Mg²⁺/Ge⁴⁺ in the resulting spinel solid solutions of ZnGa_2−x(Mg/Ge)_xO₄:Cr³⁺ (x = 0–1.25). Moreover, the defect clusters cannot only store and recharge visible and UV radiations that contributes to the long lasting NIR persistent luminescence but also can enhance the NIR emission intensity at ~695 nm. The persistent luminescence induced by UV light excitation exhibits an improvement at a deeper trap depth, but it follows an opposite law through visible light excitation. The prepared nanoparticles have the advantages of intense NIR emission, long lasting afterglow, and excellent rechargeability for visible/UV radiations, so they are the potential nanoprobes for long-term bio imaging in living animals.     

Novel preparation of ITO nanocrystalline films with plasmon electrochromic properties by the sol-gel method using benzoylacetone as a chemical modifier

In this paper, benzoylacetone (BzAcH) was introduced as a chelating agent to the sol-gel technique to fabricate indium tin oxide (ITO) nanocrystalline films. BzAcH was found to decrease the grain size of the ITO film, and the growth of ITO nanocrystals was controlled by varying the BzAcH content. ITO nanocrystalline films prepared by this method showed significant localized surface plasmon resonance (LSPR) absorption features that could be manipulated electrically by electrochemical doping. Plasmonic electrochromism realized in ITO films indicated a strongly reversible and persistent variation of the film transmittance in the near-infrared region (NIR). Furthermore, the plasmon electrochromic mechanism of ITO nanocrystals is discussed in this paper.     

Structural,optical and morphological evolution of Ga2O3/Al2O3 (0001) films grown at various temperatures by pulsed laser deposition

This study systematically investigated the structural, optical, and morphological evolution of Gallium oxide (Ga₂O₃) films deposited at different substrate temperatures on Al₂O₃(0001) using pulsed laser deposition (PLD). The thickness of the Ga₂O₃ films was standardized in order to eliminate its effect on the film properties. The effect of substrate temperature from room temperature to 600 °C on the film's transmittance, crystalline structure, chemical composition and surface morphology, was explored. The plasma species generated during the deposition of the PLD process were monitored and analyzed employing in situ optical emission spectroscopy. The deposition rate of the films decreased with increasing substrate temperature. X-ray photoelectron spectroscopy was used to detect both Ga³⁺ and Ga ⁺ oxidation states in all prepared films, which indicated substoichiometric Ga₂O₃ films deficient in oxygen. The percentage of non-lattice oxygen decreased with increasing substrate temperature. At optimal condition, mono-crystaline β-Ga₂O₃ was produced with a high visible and near-infrared transmittance, large grain size and smooth surface, which is suitable for the application in high-performance power electric devices and photoelectronic devices.     

Influence of Ca/Al Ratio on Properties of Amorphous/Nanocrystalline Cu–Al–Ca–O Thin Films

This article reports the characterization of thin films sputtered from CuAl_1?xCa_xO targets (x = 0, 0.05, 0.1, 0.15, and 0.2) at room temperature. All films exhibit amorphous/nanocrystalline structures. Their transparency increases slightly with the addition of Ca. Furthermore, the resistivity decreases as the Ca/Al atomic ratio increases. Transmission electron microscopy with energy dispersive spectroscopy mapping indicates that the composition is uniform throughout the films deposited from the highest Ca doping concentration target. Some nanocrystals are present at the top surface of the CuAl_0.8Ca_0.2O thin film as well as the interface region between the CuAl_0.8Ca_0.2O thin film and the glass substrate, whereas the interior of the film is pretty amorphous with some embedded nanocrystals. X‐ray photoelectron spectroscopy shows that the Cu²⁺/Cu⁺ atomic ratio increases with the Ca/Al atomic ratio, indicating the enhancement of p‐type conductivity from the nonisovalent Cu–O alloying.     

Enhanced photocatalytic and antifungal activity of ZnO–Cu2+and Ag@ZnO–Cu2+ materials

Zinc oxide is one of the most versatile nanostructured materials with a broad range of applications. Besides, its physicochemical properties can be tuned easily by synthesis conditions to be optimal for a specific application. In our group, we aim for the production of visible light-active materials with enhanced antimicrobial activity. Thus, we synthesize ZnO–Cu²⁺and Ag@ZnO–Cu²⁺ by using a fast and robust microwave solvothermal reaction. We investigate the limit of solubility of Cu²⁺into ZnO lattice producing Cu doped ZnO materials with different doping levels (1, 2, 3, 4, and 5 at. %, Cu/Zn). We also investigate the role of the copper precursor, using copper(II) acetate or copper(II) sulfate as model precursors. Copper acetate incorporates more efficiently into ZnO lattice by decreasing the Eg value of the doped materials at low doping levels. Furthermore, we study the composites Ag@ZnO–Cu²⁺ aiming to reduce doping levels and to improve antimicrobial activity. Characterization of the materials by different techniques demonstrates their uniform size, purity, crystallinity, and visible light activity. In this study, we evaluate airborne fungal contamination and demonstrate the capacity of ZnO–Cu²⁺ and Ag@ZnO–Cu²⁺ to inhibit fungal growth. We studied the microbiological quality of indoor air (vivarium) by sampling air under different conditions. By sampling air with a photocatalytic prototype, the amount of fungi in the air decreases considerably, particularly fungi that can enter the lung. In addition, ZnO–Cu²⁺ shows excellent antifungal activity against Candida sp at low doses. We use Atomic force microscopy (AFM) and holotomographic microscopy (HTM) to provide further evidence on the capacity of the prepared materials to achieve effective damage to fungal cells and to inhibit biofilm formation.     

CuxS/PAN 3D Nanofiber Mats as Ultra‐Lightweight and Flexible Electromagnetic Interference Shielding Materials

Shielding materials are becoming increasingly important, but present materials suffer from either insufficient mechanical stability or limited shielding properties. In this study, 3D flexible copper sulfide (Cu_xS)/polyacrylonitrile (PAN) nanofiber mats are developed via air spinning followed by chemical reaction with copper salt. The Cu_xS/PAN nanofiber mats exhibit an ultra‐lightweight density of 0.044 g cm^?3 and a thickness of 0.423 mm. Stable electromagnetic interference (EMI) shielding effectiveness (SE) (29–31 dB) of the Cu_xS/PAN composite is achieved in the frequency range of 500–3000 MHz. EMI SE per unit surface density of 16 655.92 dB cm² g^?1 is several orders of magnitude higher than most copper sulfide containing EMI shielding materials reported in literature. In addition, the introduction of the Cu_xS improves the thermal stability and launderability of the PAN mats giving the mats thermal, mechanical, and aqueous stability. Finally, the shielding mechanism of the Cu_xS/PAN nanofiber mats for electromagnetic waves is proposed     

Tungsten doped M-phase VO2 mesoporous nanocrystals with enhanced comprehensive thermochromic properties for smart windows

The phase transition temperature (~68?°C) of M-VO₂ film can be lowered significantly by tungsten (W) doping into the crystal lattice of VO₂ due to the reduction of the strength of V-V pair interaction. However, W doping was always coupled with a serious weakening of luminous transmittance and solar modulation efficiency because W dopants can increase the electron concentration of VO₂ film. Herein, the simultaneous introduction of W dopants and mesopores into M-VO₂ nanocrystals was employed to prepare VO₂ film. Interestingly, the obtained 0.4?at%?W-doped mesoporous VO₂ nanocrystals based composite films exhibited enhanced comprehensive thermochromic performance with excellent solar modulation efficiency (ΔT_sol = 11.4%), suitable luminous transmittance (T_lum = 61.6%) and low phase transition temperature around 43?°C, much lower than 65.3?°C of undoped VO₂. It was demonstrated that the lower phase transition temperature of VO₂ can be primarily attributed to abundant lattice distortion after W doping, whereas the mesoporous structure can facilitate the uniform distribution of W dopants in VO₂ nanocrystals, enhance the luminous transmittance and guarantee enough VO₂ nanocrystals in the composite film to keep relatively high solar modulation efficiency. Therefore, this work can provide a new way to balance the three important parameters for the thermochromic performance of VO₂ film (ΔT_sol, T_lum and T_c) and probably promote the application of VO₂ nanocrystals in the energy efficient windows.     

The state of Cu2+ ions and highly dispersed CuS immobilized in PVA-PAA polymer matrix

Microheterogeneous water swelling polymer compositions containing highly dispersed semiconductive component CuS have been obtained on the basis of PVA-PAA mixtures. Average CuS particle size range is 8–13 nm. The formation of highly dispersed CuS phase takes place upon attraction of coordinately bonded (immobilized) Cu²⁺ ions and sulfide ions. The interaction occurs directly in polymer matrix bulk (in situ method). According to IR spectroscopy data, the state of Cu²⁺ ions in polymer matrix is characterized by formation of coordination centers with donor-acceptor and ionic bonds between Cu²⁺ and carboxylic groups of PAA. Structure characteristics of highly dispersed polymer-CuS compositions (particle size distribution, crystallite size, specific surface, concentration) and phase boundary intermolecular interactions type in polymer CuS compositions have been studied using X-ray scattering and IR spectroscopy methods. Such compositions possess rather high swelling (～400 wt%) and under hydrogel state display good mechanical properties (E=0.6 MPa,σ _b MPa, ?=370%) and permeability (～2 l/m²·h).     

Preparation and electrical properties of metal sulfides–amidoximated PAN composite film

To improve the electrical conductivity of polyacrylonitrile (PAN) film, metallic sulfides and PAN composite film were prepared by the chelating method. Dense PAN film and porous PAN film were prepared by dry process and wet process, respectively. These PAN films were treated to NH₂OH solution to introduce the amidoxime group coordinated with metallic ion. Cu⁺² and Cd⁺² ions were adsorbed to amidoximated PAN films, the sulfur ion was treated with metal-adsorbed PAN films, and thus CuS—and CdS–PAN composite films were prepared. The adsorptive capacity of amidoximated PAN film for the Cu⁺² ion was independent of the morphology of the PAN film, but the adsorptive capacity of the Cd⁺² ion on amidoximated PAN film was dependent on porosity of the polymer. Adsorptive capacity of amidoximated porous PAN film for Cd⁺² was improved about four times than that of amidoximated dense PAN film. The electrical conductivities of CuS–dense and porous PAN composite film were both 10^?1 S/cm in optimum condition, but because of the difference in adsorptive capacity, the electrical conductivities of CdS–dense and CdS–porous PAN composite films were 10^?9 S/cm and 10^?4 S/cm, respectively. Additionally, because CdS was known as a photoconductive material, the photoconductive properties of CdS–porous PAN composite film were investigated.     

Controlling thickness to tune performance of high-mobility transparent conducting films deposited from Ga-doped ZnO ceramic target

Structure modification has been found to tune significantly the transparent-conducting performance, especially mobility and conductivity of hydrogenated Ga-doped ZnO (HGZO) films. The strong correlation between film thickness and mobility of the films is revealed. The mobility increases quickly with increasing the thickness from 350 to 900 nm, and then tends to be saturated at further thicknesses. A higher mobility than 50 cm²/Vs can be achieved, which is an extra-high value for polycrystalline ZnO films deposited by using the sputtering technique. The thickness-dependent mobility originates from scatterings on grain boundaries and dislocation-induced defects controlled by thin-film growth. Based on the Volmer-Weber model, an expansion model is built up to describe the thickness-dependent crystal growth of the HGZO films, especially at the thick films. As a result, the 800 nm-thick HGZO film obtains the highest performance with high mobility of 51.5 cm²/Vs, low resistivity of 5.3 × 10^?4 Ωcm, and good transmittance of 83.3 %.     

Structural,optical and electrical properties of indium doped Cu2ZnSn(S,Se)4 thin films synthesized by the DC and RF reactive magnetron cosputtering

Element doping into the Cu₂ZnSn(S,Se)₄ (CZTSSe) absorber is an effective method to optimize the performance of thin film solar cells. In this study, the Cu₂In_xZn_1-xSn(S,Se)₄ (CIZTSSe) precursor film was deposited by magnetron cosputtering technique using indium (In) and quaternary Cu₂ZnSnS₄ (CZTS) as targets. Meanwhile, the In content was controlled using the direct current (DC) power on In target (P_In). A single kesterite CIZTSSe alloy was formed by successfully doping a small number of In³⁺ into the main lattice of CZTSSe. The partial Zn²⁺ cations were substituted by In³⁺ ions, resulting in improving properties of CZTSSe films. Morphological analysis showed that large grain CIZTSSe films could be obtained by doping In. The well-distributed, smooth, and dense film was obtained when the P_In was 30 W. The band gap of CIZTSSe could be continuously adjusted from 1.27 to 1.05 eV as P_In increased from 0 to 40 W. In addition, the CIZTSSe alloy thin film at P_In = 30 W exhibited the best p-type conductivity with Hall mobility of 6.87 cm²V^?1s^?1, which is a potential material as the absorption layer of high-performance solar cells.     

Photoluminescence and third-order nonlinear optical limiting properties of Sn1-xNdxO2 thin films deposited via spray pyrolysis

In the present work, spray pyrolysis method was adopted to synthesis nano thin films of Sn_1-xNd_xO₂ (x = 0.01 to 0.1) possessing tetragonal structure with (1 1 0) plane orientation. Nd doping reduced the overall crystallinity of the films, however Sn_0.92Nd_0.08O₂ film showed crystallite size of 18.7 nm, similar to that of the pure film. The morphology changed to distinct grains at lower doping concentration, beyond which a fibrous nature evolved but again changed to smaller grains with further increase in the doping. The oxidation states of the constituent elements were confirmed using XPS. The transmittance of the films reduced due to incorporation of Nd ions. A decrease in the energy band gap was also noticed in the films following dopant addition. The PL emissions corresponding to the Nd ion transitions was found in the NIR region resulting from internal 4f-shell transitions of Nd³⁺ ions. Other defect related emissions like the one from oxygen vacancies also showed up in the UV and visible wavelength regions, which were responsible for a near white light emission. The third-order optical nonlinearity of the films was confirmed using the Z-scan technique. All the Sn_1-xNd_xO₂ films till 8 at. % of doping showed reverse saturable absorption. The highest and lowest nonlinear absorption coefficient was exhibited by Sn_0.92Nd_0.08O₂ and Sn_0.98Nd_0.02O₂ films, respectively. Depending on the Nd concentration, the films either showed self-focusing or self-defocusing behavior and influenced the nonlinear refractive indices of the films. The least optical limiting values among the doped films was obtained in the range of 1.73 kJ/cm² for Sn_0.92Nd_0.08O₂ films.     

Effect of swelling pretreatment on the deposition structure on electroless copper of polyacrylonitrile nanocomposites for electromagnetic interference shielding

In this investigation, the electroless copper method with various cupric sulfate concentrations (0.24, 0.36, 0.48, 0.60M) without sensitizing and activating is used to deposit electroless copper compounds (CuS) on the swelling pretreatment polyacrylonitrile(SPAN) surface for electromagnetic interference (EMI) shielding materials. The acetic acid can swell polyacrylonitrile (PAN) effectively which donot destroy the hexagonal structure of polyacrylonitrile, only looses the molecule chain of polyacrylonitrile then the hexagonal CuS crystal deposits on the SPAN easily, and increases the EMI shielding effectiveness (SE) of CuS‐SPAN composites. However, the nearly amorphous of CuS deposits on the surface of without swelling pretreatment PAN(CuS‐PAN). The EMI SE of CuS‐SPAN composites are better than those of CuS‐PAN, 10–15 dB larger from CuS‐PAN. In the study, the best EMI SE of CuS‐SPAN and CuS‐PAN composites are about 30–35 dB and 18–20 dB respectively, as the cupric ion concentration is 0.48M. From the high resolution transmission electron micrographs(HR‐TEM) analysis, there are two structures, face‐centered cubic(FCC) Cu_2‐xS crystal in the inner layer of CuS‐SPAN composite and hexagonal CuS crystal on the outer layer of CuS‐SPAN composite, in the SPAN as the cupric ion concentration is 0.48M. The particle size distribution of Cu_2‐xS in the inner layer of CuS‐SPAN is from 6 to 30 nm. However, the major particle size distribution of Cu_2‐xS in the inner layer of CuS‐SPAN is from 15 to 20 nm. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008