A new method for the evaluation of biodegradable plastic using coated cellulose paper

A highly sensitive analytical method for evaluation of poly(L-lactide) (PLA), poly(epsilon-caprolactone) (PCL), poly(beta-hydroxybutyrate) (PHB), and poly(butylene succinate) (PBS) degradability was developed using coated cellulose paper, prepared by penetration and adhesion of these plastics into/onto the cellulose paper. Enzymatic degradability of the obtained plastic coated papers was evaluated using various commercial proteases and lipases. PLA coated paper was highly susceptible to subtilisin and mammalian enzymes, alpha-chymotrypsin, elastase and trypsin. To our knowledge, this is the first report on the degradation of PLA coated paper using subtilisin and mammalian enzymes. Almost all lipase preparations degraded PCL and PHB coated papers but not PBS coated paper. The biodegradability of plastic coated paper was greater than that of plastic powder. The penetration of plastic into cellulose paper by coating improved the plastic degradability, and can be regulated easily.     

水凝胶涂覆纸喷雾离子化用于生物流体样品直接质谱分析

基于琼脂糖水凝胶涂覆的纸基质,实现了纸喷雾离子化,建立了一种新的纸喷雾离子化质谱技术,直接分析生物流体样品。利用纸表面涂覆的水凝胶材料限制液滴的扩散,使互不相溶的喷雾溶剂液滴与生物样品液滴之间形成液液萃取,提高了检测灵敏度。同时通过限制液滴扩散,减少了喷雾溶剂挥发面积,降低了挥发速度,获得了时间更长的稳定质谱信号,可对生物流体样品中的低丰度药物快速、准确定量。相较于常规纸喷雾离子化,该方法喷雾时间延长近10倍,分析物信号提高近100倍,定量分析全血和尿液中的药物,检出限可降低7～33倍。方法材料制备简单,方便快捷,灵敏度高,在现场临床诊断上具有很大的应用潜力。     

Localized surface plasmon resonance interfaces coated with poly[3-(pyrrolyl)carboxylic acid] for histidine-tagged peptide sensing

The paper reports on a novel localized surface plasmon resonance (LSPR) substrate architecture for the immobilization and detection of histidine-tagged peptides. The LSPR interface consists of an ITO (indium tin oxide) substrate coated with gold nanostructures. The latter are obtained by thermal deposition of a thin (2 nm thick) gold film followed by post-annealing at 500 °C. The LSPR interface was coated with poly[3-(pyrrolyl)carboxylic acid] thin films using electrochemical means. The ability of the LSPR interfaces coated with poly[3-(pyrrolyl)carboxylic acid] to chelate copper ions was investigated. Once loaded with metal ions, the modified LSPR interface was able to bind specifically to histidine-tagged peptides. The binding process was followed using LSPR.     

The adsorption behavior of p-hydroxybenzoic acid on a silver-coated filter paper by surface enhanced Raman scattering

On dried filter paper coated with silver nanoparticles, surface-enhanced Raman scattering (SERS) spectra of p-hydroxybenzoic acid (PHBA) were studied, and high-quality SERS spectra were obtained, indicating that the silver-coated filter paper is a highly SERS-active substrate. The analysis showed that the adsorption behavior of PHBA molecules on silver nanoparticles coated on filter paper was different from that in silver aqueous colloids. On the filter paper, it was found that the SERS spectra of PHBA changed with the proportion of PHBA molecules and silver nanoparticles, indicating that the adsorption behavior of PHBA molecules changed with the proportion. The probable reasons are given.     

Octadecyltrimethoxysilane functionalized ZnO nanorods as a novel coating for solid-phase microextraction with strong hydrophobic surface

In this paper, we have, for the first time, proposed an approach by combining self-assembled monolayers (SAMs) and nanomaterials (NMs) for the preparation of novel solid-phase microextraction (SPME) coatings. The self-assembly of octadecyltrimethoxysilane (OTMS) on the surface of ZnO nanorods (ZNRs) was selected as a model system to demonstrate the feasibility of this approach. The functionalization of OTMS on the surface of ZNRs was characterized and confirmed using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The OTMS-ZNRs coated fiber exhibited stronger hydrophobicity after functionalization, and its extraction efficiency for non-polar benzene homologues was increased by a factor of 1.5-3.6 when compared to a ZNRs fiber with almost identical thickness and fa?ade. In contrast, the extraction efficiency of the OTMS-ZNRs coated fiber for polar aldehydes was 1.6-4.0-fold lower than that of the ZNRs coated fiber, further indicating its enhanced surface hydrophobicity. The OTMS-ZNRs coated fiber revealed a much higher capacity upon increasing the OTMS layer thickness to 5 μm, leading to a factor of 12.0-13.4 and 1.8-2.5 increase in extraction efficiency for the benzene homologues relative to a ZNRs coated fiber and a commercial PDMS fiber, respectively. The developed HS-SPME-GC method using the OTMS-ZNRs coated fiber was successfully applied to the determination of the benzene homologues in limnetic water samples with recovery ranging from 83 to 113% and relative standard deviations (RSDs) of less than 8%.     

Synthesis of high performance,conductive PEDOT‐coated polyester yarns by OCVD technique

Production of high performance conductive textile yarn fibers for different electronic applications has become a prominent area of many research groups throughout the world. We have used oxidative chemical vapor deposition (OCVD) technique to coat flexible and high strength polyester yarns with conjugated polymer, poly(3,4‐ethylenedioxythiophene) (PEDOT) in presence of ferric (III) chloride (FeCl₃) oxidant. OCVD is an efficient solvent free technique used to get uniform, thin, and highly conductive polymer layers on different substrates. In this paper, PEDOT‐coated polyester (PET) yarns were prepared under specific reaction conditions, and the electrical, mechanical and thermal properties were compared to previously studied PEDOT‐coated viscose yarns. Scanning electron microscopy (SEM) and FT‐IR analysis revealed that polymerization of PEDOT on the surface of the polyester yarns has been taken place successfully and structural analysis showed that PEDOT has strong interactions with viscose yarns as compared to PET yarns. The voltage–current (V–I) characteristics showed that PET yarns are more conductive than PEDOT‐coated viscose yarns. The variation in the conductivity of PEDOT‐coated yarns and the heat generation properties during the flow of current through coated yarns for longer period of time, was studied by time–current (t–I) characteristics. Thermogravimeteric analysis (TGA) was employed to investigate the thermal properties and the amount of PEDOT in PEDOT‐coated PET yarns compared to PEDOT‐coated viscose. The effect of PEDOT coating and ferric (III) chloride concentration on the mechanical properties of coated yarns was evaluated by tensile testing. The obtained PEDOT‐coated conductive polyester yarns could be used in smart clothing for medical and military applications. Copyright © 2011 John Wiley & Sons, Ltd.     

Electrophoretic separation of environmentally important phenolic compounds using montomorillonite-coated fused-silica capillaries

This paper reports a simple procedure for coating fused-silica capillaries with poly(diallyldimethyl ammonium chloride) and montmorillonite. The coated capillaries were characterized by performing EOF measurements as a function of buffer pH, number of layers of coating, and number of runs (stability). The coated capillaries showed a highly stable mu(EOF) (run-to-run RSD less than 1.5%, n = 20), allowing continuous use for several days without conditioning. The coated capillaries were then used for the effective separation of nine environmentally important phenolic compounds showing a significant improvement in the resolution, when compared to bare fused-silica capillaries. The EOF of the coated capillaries was constant in alkaline solutions (pH > or = 7), allowing the optimization of the separation conditions of phenolic compounds without significantly affecting the mu(EOF).     

β-Cyclodextrin modified filter paper based solid phase extraction–room temperature phosphorimetry for preconcentration and determination of nitrogen heterocyclic compounds in water samples

A highly selective method for the preconcentration and the determination of nitrogen heterocyclic compounds (NHCs) by solid phase extraction–room temperature phosphorimetry (SPE–RTP) was described. The β-cyclodextrin (β-CD) coated filter paper was synthesized and used as the SPE membrane and the substrate for the measurement of RTP emission of NHCs in water samples. The RTP characteristics of NHCs on the coated filter paper were studied. The conditions for the measurement of RTP intensities of NPAHs were discussed and optimized in detail. Several experimental parameters related to the preconcentration of NHCs on the coated filter paper were also examined. The experimental results showed that the β-CD coated filter paper could selectively extract NHCs containing three benzene rings with a high enrichment efficiency. The limit of detections of carbazole, 7,8-benzoquinoline and phenanthridine were found to be 9.1 × 10⁻¹⁴, 8.3 × 10⁻¹³ and 7.8 × 10⁻¹³ mol mL⁻¹, respectively. The proposed method was applied to the analysis of NHCs in water samples. The recoveries of carbazole, 7,8-benzoquinoline and phenanthridine in water samples was in the range of 86.1–109.3%.     

Encapsulation of Organic Pigment Particles with Silica via Sol-Gel Process

This paper presented a novel preparation method of silica coated organic pigment. In this approach, the surfaces of the organic pigment were first orderly modified by poly(sodium 4-styrenesulfonate) (PSS) and poly(diallyldimethylammonium chloride) (PDADMAC), then coated by silica via sol-gel process of tetraethylorthosilicate (TEOS). The results showed that PVP, pH value, water and TEOS contents had significant influence on the morphology of the silica encapsulated organic pigment. Organic pigments coated silica by this approach could scatter UV ray with wavelength less than 270 nm, and this scattering property increased with more silica coated.     

Hydrophobic octadecylamine-polyphenol film coated slow released urea via one-step spraying co-deposition

Polymer coated fertilizer has been designed for gradual release of nutritional content of fertilizer to improve the utilization efficiency. However, the better slow release property of the coated fertilizer and simplified preparation process are still a huge challenge. The hydrophobic ODA-polyphenol film coated urea was prepared by one-step spraying for excellent nutrient release performance. Octadecylamine (ODA) was used to modify poly(tannic acid) (PTA) and poly(pyrogallol) (PPG) coating on substrates and prepare the hydrophobic ODA-PTA and ODA-PPG coated urea granules. The nutrient release rate of ODA-PTA and ODA-PPG coated fertilizers was much slower than PTA and PPG coated fertilizers in water and soil. The N release longevities of ODA-PTA coated fertilizers will be extended from 2 h to 30 days compared with PTA coated fertilizers. Moreover, pot experiments showed that coated fertilizer could effectively promote plant growth. This work will provide one-step spraying co-deposition approach to fabricate hydrophobic ODA-polyphenol film coated urea to improve the N release longevity, which can shine a light on the development of new slow release fertilizers (SRFs).     

SERS of C60/C70 on gold-coated filter paper or filter film influenced by the gold thickness

SERS of C(60)/C(70) adsorbed on gold nanoparticles coated on filter paper or filter film was studied. As a new SERS substrate, dried gold-coated filter paper or filter film has a high SERS activity, whose enhancement factor can be up to about 10(5), because it avoided the influence of solvents in C(60)/C(70) solution and water in gold hydrosols. The influence of the gold thickness coated on filter paper or filter film to SERS of C(60)/C(70) adsorbed on gold nanoparticles was mainly discussed. It is indicated that the SERS effect of C(60)/C(70) was very sensitive to the distribution and aggregated characteristics of gold nanoparticles, and the SERS intensity of each mode increased at its own proportion, but it integrally tended to saturation when the thickness of colloidal gold coatings increased.     

Switchable water absorption of paper via liquid flame spray nanoparticle coating

Surface wetting/anti-wetting and liquid absorption are relevant properties of many porous solids including paper and other cellulose-based materials. Here we demonstrate how surface wetting by water and water absorption of commercially available kraft paper can be altered by thin nanoparticle coatings fabricated by liquid flame spray in facile and continuous one-step process. Surface wettability and absorption properties of paper increased with silica and decreased with titania (TiO₂) nanoparticle coatings. Moreover, the water-repellent (superhydrophobic) TiO₂ nanoparticle coated paper could be switched to superhydrophilic and water absorbing by ultraviolet illumination. The experiments revealed that although surface wetting and liquid absorption of nanoparticle coated paper are strongly related to each other, they are two distinct phenomena which do not necessarily correlate. We propose wetting regimes on the nanoparticle coated paper samples on the basis of the experimental observations.     

Sticking coefficient and processing of water vapor on organic-coated nanoaerosols

Organic-based aerosols may play an unexpectedly important role in the atmospheric processing of water vapor. In this paper, we report results of a molecular dynamics (MD) study on the sticking coefficient of water vapor on a coated particle (water droplet coated with fatty acid of radius approximately 4 nm). The sticking coefficient was found to be almost a constant (11-16%) for incident speeds around the most probable speed as opposed to 100% for water vapor incident on a pure water droplet. The sticking coefficient was found to increase with the size of the water cluster (water-Nmer) impinging the surface of the particle and was seen to approach 1 for impinging water clusters consisting of 10 molecules or more. We also computed the average energy transferred per collision for monomers impinging the surface of the coated particle and found the value to be 4.4581 kJ/mol. Most important perhaps was the fact that despite the lower sticking coefficient, the equilibrium vapor pressure of water over these inverted micelles was considerably lower due to the surface tension effects of the fatty acid layer. As such, these coated particles act as effective substrates for water vapor condensation and may play a role as cloud condensation nuclei.     

Analysis of paper by laser-induced plasma spectroscopy

Material distributions in paper and paper coatings are important factors which determine the characteristics and quality of paper. We have used laser-induced plasma spectroscopy (LIPS) to determine various properties of coated and uncoated papers. Depth profiles of double coated papers were determined. Microscopic variations of pigments in a double-coated paper were analyzed. It was observed, that the two coating layers can be distinguished, if they differ enough in composition. Filler distributions of uncoated copier papers were determined. The surface of the paper was studied for five samples containing different amounts of binder in the coating. Lateral contamination in paper analysis i.e. splash over effect of ablation was studied by varying the sampling distance and number of laser pulses used for ablation. Influence of splash over effect on lateral analysis is briefly discussed.     

Robust superhydrophobic surface fabrication by fluorine-free method on filter paper for oil/water separation

Robust superhydrophobic surface exhibiting anti-fouling and self-cleaning ability were successfully fabricated by nano TiO2 modified by γ-aminopropyltriethoxysilane (KH550) and polydimethylsiloxane (PDMS) via wire rod coating. Due to the lower surface energy of PDMS and the hierarchical structure caused by the different aggregation sizes of TiO2 nanoparticles, the contact angle of the resulting superhydrophobic coating was 154.5° and the rolling angle was 3.5°. And the coated paper still had good non-wettability under water immersion. In addition, the coated paper was tolerant to mechanical damage and various temperature conditions. Even after 40 sandpaper wear cycles, the coating can still maintain good mechanical stability and superhydrophobicity. The superhydrophobic paper was used for oil-water separation, the separation efficiency was about 98% even after used 10 times. Furthermore, the prepared superhydrophobic paper exhibited excellent self-cleaning and anti-fouling properties, as well as demonstrated superb resistance to various water solutions owing to its high hydrophobicity. Moreover, the prepared superhydrophobic paper has application prospects in the industry of special wetting materials.     

外消旋萘普生酯类在四种纤维素衍生物手性柱上分离及手性 识别机理研究

在纯聚合物型的纤维素三醋酸酯(CTA)、纤维素三苯甲酸酯(CTB)与涂敷型的CTB、纤维素三(4-甲基苯甲酸酯)(CTMB)四种纤维素衍生手性柱上成功地分离了几种外消旋萘普生酯,研究了流动相组成以及溶质的结构对手性分离的影响,探讨了纤维素衍生物手性固定相对外消旋萘普生酯手性识别的机理,得出溶质在固定相手性空腔中体积大小的适应性,尤其是立体结构上的空间适应性是手性识别的关键,不同的固定相这种适应性有所不同,     

Water vapor adsorption equilibria and mass transport in unmodified and modified cellulose fiber-based materials

Water vapor adsorption isotherms of different unmodified and coated paper samples were studied to determine their suitability as water barrier packaging materials. The sorption behavior of these samples was compared with commercially available paper. The experimental data were analyzed using the Hailwood–Horrobin (H–H), Guggenheim–Anderson–De Boer (GAB) and BET models for extraction of isotherm parameters and determination of monolayer moisture contents. The H–H and GAB models were found to provide good fits to the experimental data. The monolayer moisture content of modified papers was less than 3.0 % (dry basis) as compared to unmodified paper samples (4.20 %), at saturation. It was also observed that the sorption behavior of modified paper samples differed with substrate type. Water vapor permeability (WVP) of unmodified and coated paper samples at the temperatures of 25 and 38 °C were also measured for a wide range of vapor partial pressure gradients. The permeabilities of the modified samples were found to be generally low compared to the unmodified (reference) paper sample. Among the investigated samples, PLA and PHBV coated paper samples showed higher mass transfer resistance to water vapor transport. Furthermore, the water vapor permeabilities of different samples were found to be relatively constant up to the modest relative humidity levels; however, at the higher humidity levels they showed increasing trend with the further increase in relative humidity. Results of this study confirmed that blocking of active surface sites by coating with PLA and PHBV is the most effective way to increase the water vapor barrier properties of modified papers, thus making them the appropriate candidates for green-based food packaging materials.     

Fabrication of NiO coated SiO2 and SiO2 coated NiO for the removal of Pb2＋ ions

We have prepared silica,SiO2coated NiO and NiO coated SiO2by sol-gel method.The physicochemical properties of the desired materials were investigated by surface charge properties,scanning electron microscopy（SEM）,energy dispersive X-ray（EDX） spectroscopy,surface area measurements and X-ray diffraction（XRD） analyses.The point of zero charge（PZC） of the solid was determined by the salt addition method.In coated materials,two PZC values were noted representing the surface charge of their counterparts.The SEM image of SiO2coated NiO displays a uniform coating of silica on the surface of NiO whereas in case of NiO coated SiO2,a honeycomb like appearance was observed with highly porous structures.In the diffractograms of NiO,the characteristic peaks were suppressed in NiO coated silica however,no diffraction peak could be seen in SiO2coated NiO.Batch adsorption technique was applied for the removal of Pb2＋ions from aqueous solution.The sorption trend for Pb2＋ions was observed in the order of NiO coated SiO2〉 SiO2coated NiO 〉 NiO 〉 SiO2.This trend confirms that the coated materials have more sorption capacities than their parent counterparts.     

Production of highly conductive textile viscose yarns by chemical vapor deposition technique: a route to continuous process

An oxidative chemical vapor deposition (OCVD) process was used to coat flexible textile fiber (viscose) with highly conductive polymer, poly (3,4‐ethylenedioxythiophene) (PEDOT) in presence of ferric (III) chloride (FeCl₃) oxidant. OCVD is a solvent free process used to get uniform, thin, and highly conductive polymer layer on different substrates. In this paper, PEDOT coated viscose fibers, prepared under specific conditions, exhibited high conductivity 14.2 S/cm. The effects of polymerization conditions, such as polymerization time, oxidant concentration, dipping time of viscose fiber in oxidant solution, and drying time of oxidant treated viscose fiber, were carefully investigated. Scanning electron microscopy (SEM) and FT‐IR analysis revealed that polymerization of PEDOT on surface of viscose fiber has been taken place and structural analysis showed strong interactions between PEDOT and viscose fiber. Thermogravimetric analysis (TGA) was employed to investigate the amount of PEDOT in PEDOT coated viscose fiber and interaction of PEDOT with viscose fiber. The effect of PEDOT coating on the mechanical properties of the viscose fiber was evaluated by tensile strength testing of the coated fibers. The obtained PEDOT coated viscose fiber having high conductivity, could be used in smart clothing for medical and military applications, heat generation, and solar cell demonstrators. Copyright © 2010 John Wiley & Sons, Ltd.     

INTERACTIONS BETWEEN POLY(ETHYLENE OXIDE) COATED SURFACES AND BETWEEN SUCH SURFACES AND PROTEINS

Surfaces coated with poly(ethylene oxide) containing nonionic polymers are of interest in medical applications due to, among other things, the low adsorption of proteins on such surfaces. In this paper we have studied the interfacial properties of surfaces coated with PEO by measuring the forces acting between two such surfaces in water and across a protein solution as well as between one such surface and a surface carrying adsorbed proteins. One type of surface coating was a graft copolymer of poly(ethylene imine) and poly(ethylene oxide) where the cationic poly(ethylene imine) group anchored the polymer to negatively charged mica surfaces. Three different ways to prepare this coating was used and compared. It was found that this coating was not stable in the presence of lysozyme, a small positively charged protein, when the PEO graft density was low. The other type of coating was obtained by adsorbing ethyl(hydroxyethyl)-cellulose onto hydrophobised mica surfaces. The driving force for adsorption is in this case the hydrophobic interaction between nonpolar segments of the polymer and the surface. The EHEC coating was stable in the presence of lysozyme and the interactions between adsorbed layers of lysozyme and EHEC coated surfaces are purely repulsive due to long-range steric forces.