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1.
A new plastic scintillator was prepared from a renewable polymer source. It is composed of the mighty 2,5-diphenyloxazole and 1, 4-bis(2-methylstyryl)benzene molecules (PPO and bis-MSB), acting as primary and secondary fluorophores, respectively, together dissolved in a polylactic acid matrix—PLA. This polymer is indeed considered as the biomass-based equivalent of petroleum-derived plastics in terms of mechanical and optical properties. Subsequent to the bis-MSB emission, the emission wavelength is centered around 424 nm and the fluorescence decay time is in the nanosecond range. The material was fully characterized, and its scintillation performances were compared to a commercial PVT-based plastic scintillator: EJ-200. Like polystyrene- or polyvinyltoluene-based scintillators, the material displayed a good response linearity with the energy of the incident gamma-ray. However, the observed scintillation yield was rather modest, with a reported 500 ph/MeV value when excited with a gamma-ray-emitting 60Co source. This preliminary test could pave the way to new and renewable polymers for unexpected applications such as nuclear physics. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48724. 相似文献
2.
Because of the biocompatible and nontoxic character of both PLA (polylactide) and POSS (Polyhedral Oligomeric Silsesquioxane) nanoparticles, recently being a significant alternative for biomedical parts; the main purpose of this study was to investigate performance of the 3D-printed PLA/POSS nanocomposites with respect to the compression molded PLA/POSS specimens. Due to the higher uniformity and higher homogeneity in the distribution of POSS nanoparticles in each PLA matrix layer, mechanical tests (tensile, flexural, and toughness) revealed that the improvements in the strength, elastic modulus and fracture toughness values of the 3D-printed specimens were much higher compared to their compression molded counterparts, the benefits starting from 13% increasing up to 78%. It was also observed that there was almost no deterioration in the physical structure and mechanical properties of the 3D-printed specimens, even after keeping them 120 days at 37°C in a physiological solution prepared by using the standard PBS (phosphate buffered saline) tablet. 相似文献
3.
Patrícia S. de O. Patrício Fabiano V. Pereira Meriane C. dos Santos Patterson P. de Souza Juan P. B. Roa Rodrigo L. Orefice 《应用聚合物科学杂志》2013,127(5):3613-3621
Bionanocomposites based on polyhydroxybutyrate (PHB) and cellulose nanowhiskers (CNWs) were prepared by dispersing CNWs in poly(ethylene glycol) (PEG) plasticizer subsequently incorporating the CNWs/PEG suspensions in the matrix. The thermal properties of the nanocomposites indicate an enlargement in the processing window in comparison to the neat PHB. The nanocomposites showed a remarkable increase in the strain level (50 times related to the neat PHB), without a significant loss of the tensile strength with the incorporation of small concentrations of CNWs in the final nanocomposite (up to 0.45 wt %). This behavior was explained in terms of a considerable chain orientation promoted by the presence of CNWs in the same direction of the applied load, which activated shear flow of the polymer matrix. The results described here can be explored to extend the applications of this biopolymer. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 相似文献
4.
Laura Sisti Grazia Totaro Maurizio Fiorini Annamaria Celli Christian Coelho Mohammed Hennous Vincent Verney Fabrice Leroux 《应用聚合物科学杂志》2013,130(3):1931-1940
A series of poly(butylene succinate) (PBS) containing organo‐modified layered double hydroxide (LDH) are prepared by melt compounding and by in situ polymerization of succinic ester and 1,4‐butanediol. Various LDHs intercalated with renewable organic anions are used. More specifically, lauryl sulfate, stearate, succinate, adipate, sebacate, citrate, and ricinoleate ions are used as LDHs organo‐modifiers. The thermal, rheological, and dynamic mechanical properties of the samples are investigated. The results reveal a general mechanical reinforcement imparted by the clays. Significant changes are observed for the in situ polymerized nanocomposites, especially for LDH stearate which improves the properties of PBS nanostructure, whereas very few differences are observed for the other samples. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1931–1940, 2013 相似文献
5.
Brown seaweed Padina tetrastromatica (PTS)‐Zinc oxide (ZnO) composites were prepared by chemical precipitation method. The characteristic peaks of PTS and ZnO were confirmed by Fourier transform infrared spectroscopy. X‐ray diffraction study was confirmed the formation of ZnO with hexagonal wurtzite phase. Surface morphology and particle's distribution of ZnO were characterized by scanning electron microscopy. Transmission Electron microscopy image reveals that ZnO nanorods are in the size range of 14–164 nm having uniformly blended with polysaccharide of seaweed. Ultraviolet‐Visible absorption spectra indicated the sharp absorption peak at 219 nm and broad absorption peak in the 250–350 nm range. Fluorescence spectra shows the broad blue‐violet emissions is around at 380–480 nm. Because of the interaction between polysaccharide and ZnO nanorods/particles, the prepared seaweed‐ZnO composite exhibit better antibacterial activity than pure ZnO nanoparticles. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40948. 相似文献
6.
Microbial cellulose as a support for photocatalytic oxidation of toluene using TiO2 nanoparticles 下载免费PDF全文
The aim of this study was to investigate the feasibility of toluene degradation using impregnated microbial cellulose (MC) with titanium dioxide (TiO2) nanoparticles (MC/TiO2). The effects of the initial toluene concentration and ultraviolet (UV) source on the degradation efficiency of toluene have been evaluated. The experimental results showed that the rate of toluene degradation decreased with an increasing of the inlet toluene concentration. After 40 min reaction time, the decomposition rate (%) of toluene decreased from 72.3% to 36.02% for experiments conducted at 100 and 500 ppm, respectively. The degradation efficiency of toluene decreased with application of UVA source instead of UVC source. The toluene degradation efficiency (%) reached to 87.79% and 76.87% for UVC and UVA irradiation, respectively. At initial toluene concentration of 100 mg/L, toluene degradation efficiency for photocatalysis and photolysis processes were 70.2% and 10.65%, respectively; indicating that the photocatalytic degradation efficiency is significantly higher than that of photolytic degradation efficiency. Furthermore, photocatalytic degradation kinetics of toluene was studied and the rates of degradation were found to conform to pseudo‐second‐order kinetic. As shown in the present study, impregnation of TiO2 nanoparticles on MC/TiO2 significantly increases toluene removal for short exposure time. It can be concluded that the MC acted as a local toluene concentrator by adsorbing pollutants from the air stream, and thereby diffusing them to the TiO2 nanoparticles for photodegradation. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43051. 相似文献
7.
Polylactic acid (PLA)‐based nanocomposites comprising two different types of nanofillers, i.e. sepiolite (SEP) and nano calcium carbonate (NCC), were prepared by internal mixing and injection molding. Because of the different aspect ratio, surface area, and surface property of the nanofillers, their effects on the morphological, mechanical, dynamic mechanical, rheological, and thermal properties of the nanocomposites were shown to be very different. NCC demonstrated more uniform particle dispersion and matrix compatibility than did SEP because of the former's surface treatment, thus leading to higher strength and strain‐at‐failure of PLA/NCC composites. On the other hand, larger aspect ratio and surface area of SEP caused higher melt viscosity, stronger shear thinning, and better thermal resistance of PLA/SEP composites. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 相似文献
8.
Viviana Moreno-Serna Maximiliano Méndez-López Alejandro Vásquez-Espinal Cesar Saldías Ángel Leiva 《应用聚合物科学杂志》2020,137(36):49075
Biohybrid nanocomposite films were obtained through a simple two-step methodology. Films of chitosan/poly(3-hexylthiophene) (CS/P3HT) were used as polymer matrices for the in-situ synthesis and stabilization of CdSe quantum dots. The biohybrid materials were characterized by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), Raman spectroscopy, UV–visible spectroscopy, thermogravimetric analysis (TGA), field emission scanning electron microscope (FESEM), high-resolution transmission electron microscopy (HRTEM), and photoluminescence spectroscopy (PL). The effects of the P3HT composition on the properties of the QDs in the films were analyzed. The results confirmed that CS/P3HT films provided an adequately confining matrix for the growth of CdSe QDs with a fairly uniform size and revealed that the interactions between the CdSe nanoparticles and the CS/P3HT matrix mainly involved the OH and NH2 groups. The optical band gaps of the biohybrid nanocomposite films were estimated. The results of photoluminescence revealed that a charge transfer phenomenon occurred in the polymer system. Finally, theoretical analyses suggest that the CdSe QDs would be preferentially located onto the chitosan domains. 相似文献
9.
This study presents a new type of composite consisting of piezoelectric poly(γ-benzyl-α, l -glutamate) (PBLG) polymer fibers, which contain a large dipole moment, and the elastomer polydimethylsiloxane (PDMS) as the matrix material. PBLG microfibers were fabricated and polarized using the electrospinning method and cast in PDMS to form a unidirectional continuous-fiber composite. The PBLG/PDMS composite was characterized based on various aspects such as crystalline structure, mechanical properties, piezoelectricity, and electromechanical response. The piezoelectric charge constants in the transverse and longitudinal modes were measured to be 10.2 and 54 pC/N, respectively, which are the largest piezoelectric coefficients of biocompatible polymers up to date. The thin PBLG/PDMS composite film can produce up to 200 mV peak-to-peak under sinusoidal actuation and exhibit ultra-sensitivity up to 615 mV N−1. These results show the great potential of the highly flexible piezoelectric polymer fiber-based composite for use in a variety of applications such as energy harvesting devices, biomechanical self-powered structures, and force sensors. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48884. 相似文献
10.
Caroline Silva Danna Igor Osorio‐Román Guilherme Dognani Carlos Jose Leopoldo Constantino Vivechana Agarwal Aldo Eloizo Job 《应用聚合物科学杂志》2017,134(43)
This article presents the fabrication and characterization of polyisoprene fluorescent films doped with CdTe quantum dots (QDs). The biopolymer (polyisoprene) is extracted from natural rubber latex, generating flexible and transparent films in visible range (transmittance over 90%) ideal as a matrix to support QDs. The water solubility of the biopolymer facilitates its doping with water dispersed QDs at room temperature to obtain the fluorescent films. Thermogravimetric analysis reveals that QDs have no significant effect on the thermal properties of the biopolymer. Photophysical characterization of the solution and solid state (films) of the QDs evidenced that the polymer matrix does not influence its emission properties, the maximum fluorescence peaks have only 2 nm of difference between the solution and solid state (films) samples. Therefore, polyisoprene from natural rubber can be considered as an excellent flexible matrix to fabricate fluorescent films with QDs. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45459. 相似文献
11.
Optimized synthesis,characterization, and antibacterial activity of an alginate–cupric oxide bionanocomposite 下载免费PDF全文
In this research, the structural features and optimal conditions for the synthesis of an alginate–CuO nanocomposite with the highest antibacterial activity were investigated. CuO nanoparticles (NPs) and the alginate biopolymer were synthesized chemically and biologically, respectively. Nine nanocomposite compounds were produced on the basis of the Taguchi method with different levels of CuO NPs and the alginate biopolymer nanocomposite with different stirring times. Fourier transform infrared spectroscopy, high‐resolution field emission scanning electron microscopy, and energy‐dispersive X‐ray spectroscopy analysis confirmed the formation of the nanocomposites. The nanocomposite synthesized with 8 mg/mL copper oxide NPs and 2 mg/mL alginate biopolymer with 60 min of stirring time showed the highest antibacterial activity. The results of two colony forming units and disk‐diffusion methods indicated a stronger antibacterial activity of the alginate–CuO nanocomposite compared with those of its components. The alginate–CuO nanocomposite showed the potential ability to act as an antimicrobial agent against Gram‐negative and Gram‐positive bacteria. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45682. 相似文献
12.
This work aims at preparing and characterizing poly(butyl acrylate) (PBA)—laponite (LRD) nanocomposite nanoparticles and nanocomposite core (PBA‐LRD)‐shell poly(methyl methacrylate) (PMMA) nanoparticles, on the one hand, and the morphology and properties of poly(lactic acid) (PLA)‐based blends containing PBA‐LRD nanocomposite nanoparticles or (PBA‐LRD)/PMMA core–shell nanoparticles as the dispersed phase, on the other hand. The PBA and (PBA‐LRD)/PMMA nanoparticles were synthesized by miniemulsion or emulsion polymerization using LRD platelets modified by 3‐methacryloxypropyltrimethoxysilane (MPTMS). The grafting of MPTMS onto the LRD surfaces was characterized qualitatively using FTIR and quantitatively using thermogravimetric analysis (TGA). The amounts of LRD in the PBA‐LRD nanocomposites were characterized by TGA. The PBA/PMMA core–shell particles were analyzed by 1H‐NMR. Their morphology was confirmed by SEM and TEM. Mechanical properties of (PBA‐LRD)/PLA blends and (PBA‐LRD)/PMMA/PLA ones were tested and compared with those of the pure PLA, showing that core–shell particles allowed increasing impact strength of the PLA while minimizing loss in Young modulus and tensile strength. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 相似文献
13.
Low noise ultraviolet photodetector with over 100% enhanced lifetime based on polyfluorene copolymer and ZnO nanoparticles 下载免费PDF全文
Mohsen Azadinia Mohammadreza Fathollahi Mohsen Ameri Siyavash Shabani Ezeddin Mohajerani 《应用聚合物科学杂志》2018,135(31)
Stability and noise current of a hybrid UV photodetector with inverted planar heterojunction (PHJ) structure indium‐tin‐oxide/ZnO nanoparticles (NPs)/poly[9,9′‐dioctyl‐fluorene‐2,7‐diyl]‐copoly[diphenyl‐p‐tolyl‐amine‐4,4′‐diyl] (BFE)/Ag are investigated. ZnO NPs as the acceptor and BFE as the donor were deposited as the active layer. Under UV light illumination, light to dark current ratio of about 102 is observed at a very low bias voltage of ?1.5 V. The spectral response of the device is located near UV region with a maximum responsivity of ~57 mA/W at wavelength of 350 nm. In particular, the prepared device exhibits remarkably higher photoresponse (~350%) and stability (~115%) enhancement under ambient condition compared to the reference device. In addition, the presented results show that the noise current of our device with PHJ structure is about an order of magnitude lower than that of commonly used bulk heterojunction system. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46533. 相似文献
14.
Mohammad Mirzaei Sayed Alireza Hassani Najafabadi Majid Abdouss Saman Azodi‐Deilami Ebadullah Asadi Mohammad Reza Milani Hosseini Majid Piramoon 《应用聚合物科学杂志》2013,128(3):1557-1562
A polyacrylate tetracycline (TC) selective microporous molecularly imprinted polymer was prepared in three different porogenic solvents (chloroform, acetonitrile, and methanol) via precipitation polymerization, using methacrylic acid monomer, ethylene glycol dimethacrylate crosslinker, and TC as template. In all three solvents this method produced microporous particles in the scale range (200–400 nm), simply, quickly, cleanly, and in good yield. The effect of polarity of porogenic solvents on binding capacity was investigated. The imprinted polymer prepared in chloroform gave much higher binding capacity (KD = 198.6) for TC than the polymers prepared in acetonitrile (KD = 133.2) or methanol (KD = 104.7). The selectivity of imprinted polymers was evaluated by rebinding other structurally similar compounds. The results clearly indicated that the imprinted acrylate polymer exhibits an excellent selectivity toward TC, and has better ability to control the release of TC than the non‐imprinted polymer.© 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 相似文献
15.
Starch nanocrystals (SNC) are nanofillers of growing interest for barrier and mechanical improvement of bio‐based polymers. However, their potential use as fillers for organic coating material of industrial packaging has never been investigated. In this study, SNC processability in coating is assessed and the final properties of coated papers are measured. Coating colors composed of plasticized starch show higher Brookfield viscosity when filled with SNC even with the addition of water but rod‐coating is still possible. These diluted water‐based coatings induce paper wetting and surface crackling issues during drying as proved by drying process analysis. However no gelatinization of the SNC is observed whichever the type of drying. SNC compensate some of the water induced loss of mechanical properties of the base paper and decrease the water vapor permeability (WVP) up to 40% compared with the base paper. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39826. 相似文献
16.
ZnO is a useful material with stable physical and chemical properties for introducing surface roughness and UV-blocking properties. However, to inhibit ZnO particles’ photocatalytic degradation of peripheral organic materials, we conducted layer-by-layer (LbL) deposition with poly(sodium 4-styrenesulfonate) and poly(diallyl dimethyl ammonium chloride) to fabricate ZnO particles with an SiO2 shell with tetraethyl orthosilicate. Polylactide (PLA) films were prepared by compression molding and treated with a weak alkali solution for 0.5, 1.0, 1.5, and 2.0 h to induce hydroxyl and carboxyl groups. The LbL deposition of polyelectrolytes on the PLA film was performed to induce electrical interactions between the PLA films and ZnO composite particles. ZnO composite particles were deposited onto the surface of the PLA films with dip coating, and a stable superhydrophobic surface was developed after hexadecyl trimethoxysilane treatment via a reduction in the surface energy. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47760. 相似文献
17.
Planar conjugated 2,7‐linked carbazole blocks: Q1(2,7‐dibromo‐9‐octyl‐9H‐carbazole); Q2(7,7′‐dibromo‐9,9′‐dioctyl‐9H,9′H‐2,2′‐bicarbazole); Q3 (7‐bromo‐7′‐(7‐bromo‐9‐octyl‐9H‐carbazol‐2‐yl)‐9,9′‐dioctyl‐9H,9′H‐2,2′‐bicarbazole) were coupled with same acceptor (4,7‐di[2,5‐thiophene]‐5,6‐dioctyloxy‐2,1,3‐Benzothiadiazole) to prepare polymers HXS‐1, 2, 3 (Scheme 1 ). Bulk‐heterojunction polymer solar cells (BHJ PSCs) with these polymers were made. Power conversion efficiency of HXS‐1 was proved to be over 5.4%. It declined dramatically to 0.43% and 0.23% for HXS‐2 and 3 respectively. Their absorption and X‐ray diffraction pattern show the torsion angle in main chain increased when more carbazole units were added. More carbazoles will make polycondensation reaction more difficult to get high molecular weight polymers. The torsion angle was calculated using a semiempirical molecular orbital method. All the results pointed out that the coplanarity in the conjugated backbone was destroyed. Electron delocalization was disturbed because p‐orbital overlapping only occurs effectively in the parallel orbit so charge cannot move a longer distance. This study offers a useful and important insight to designing polymers for high performance PSCs. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 相似文献
18.
《应用聚合物科学杂志》2018,135(9)
In this work, we fabricated plasmonic organic bulk–heterojunction solar cells by inserting hydrophobic gold nanorods (GNRs) into the active layers. Power conversion efficiency was improved from 7.43% to 8.22% because the plasmonic effect of GNRs improved the light harvesting efficiency. Maximum exciton generation rate was increased from 1.35 × 10−26 to 1.51× 10−26m−3 s−1, and the electron mobility was also increased from 8.6 × 10−5 to 1.5× 10−4cm−2 V−1 s−1. As a result, the short circuit current density was improved from 15.5 to 16.7 mA cm−2—the dominant reason for performance enhancement. The open circuit voltage and fill factor were improved simultaneously. The plasmonic device showed a highest PCE of 8.43%, indicating that doping GNRs into active layers is a simple and effective way to fabricate high‐performance organic solar cells. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45920. 相似文献
19.
Fabiane Cerqueira de Almeida Carolina Oliveira de Souza Biane Oliveira Philadelpho Paulo Vitor França Lemos Lucas Guimarães Cardoso Jamille Santos Santana Jania Betania Alves da Silva Paulo Romano Cruz Correia Geany Peruch Camilloto Ederlan de Souza Ferreira Janice Izabel Druzian 《应用聚合物科学杂志》2021,138(18):50008
This study aimed to evaluate the effects of incorporation of cowpea protein isolate and cassava starch nanoparticles obtained by ultrasound on the properties of cassava starch:glycerol films. The cowpea bean protein isolate was successfully obtained with 72.5% of protein and solubility about 90%. The cassava starch nanoparticles yielded 97.85%. Increasing protein isolate concentration in starch:glycerol films resulted in a progressive reduction of water vapor permeability up to 27.0%. The cassava starch nanoparticles added films presented expressive increments in tensile strength (283.83%) as well as modulus of elasticity (204.31%), accompanied by decreasing in elongation at break (24.28%). The thermal stabilities of cassava starch films were affected by the addition of both protein isolate and cassava starch nanoparticles. The cassava starch nanoparticles obtained by ultrasound ensured the maintenance of film properties, optimizing the production time, with a higher yield, and without the need for chemical reagents. Thus, it could be useful for substitution of those obtained by acid hydrolysis. Therefore, giving rise to a trend of production of nanocomposite films suitable for reinforced packaging applications. 相似文献
20.
Stability and rheological study of sodium carboxymethyl cellulose and alginate suspensions as binders for lithium ion batteries 下载免费PDF全文
Currently, the most widely used binder in batteries is polyvinylidene fluoride with N‐methyl‐2‐pyrrolidone used as a solvent. This solvent is flammable and toxic. Here, we focus on the suitability of using water‐soluble sodium alginate (Na‐alginate) and sodium carboxymethyl cellulose (Na‐CMC) as alternative biobased binder materials for the anodes of lithium ion batteries. It reduces the environmental impact of current manufacturing processes. However, control of the rheological characteristics of the binder whilst containing active and conductive additives is key for optimized processing. Here, we perform stability and rheological measurements of Na‐alginate and Na‐CMC solutions containing varying amounts of graphite and carbon black used as active and conductive materials, respectively. Compared with the benchmark Na‐CMC, the degree of flocculation shows that for the same concentration of binder in water, Na‐alginate suspensions are more stable. The rheology measurements show that Na‐alginate slurries have a higher viscosity than Na‐CMC at a shear rate of 50 s?1 with that for a 1.5% of Na‐alginate binder being 1.26 Pa s while for Na‐CMC it was for 0.20 Pa s. The loss factor was lower for Na‐Alginate, between 2 and 3 against between 2.9 and 3.3 for Na‐CMC, showing a more developed network structure. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46217. 相似文献