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.     

Hybrid paper sheets with improved barrier properties

Hybrid paper sheets were prepared by applying a thin coating layer of cross-linked polydimethylsiloxane (PDMS) and inorganic particles onto Whatman Grade 1 filter paper substrates. Several coatings with different inorganic particle contents and types were applied onto the paper substrates to investigate the effect of the variation in the coating formulation on the (i) wetting, (ii) water barrier properties, (iii) air barrier properties, (iv) surface roughness, and (v) mechanical properties of the samples. It was revealed that the superhydrophobic hybrid paper sheets with significantly low air permeability and high water barrier properties could be prepared which is an indication that the method proposed can be used for the preparation of packaging materials.     

基于3种荧光化合物检测草酰氯气体的化学发光试纸法

研究了3种发光材料聚芴(PF)、5,5'-双(9,9-二辛基芴)-2,2'-联噻吩(F-T-T-F) 和4,7-双(5-(9,9-二丙基芴)噻吩)苯并噻二唑(3FT-BTD) 的固态化学发光。 将这3种材料吸附于滤纸上得到了相应的检测试纸,研究了其与草酰氯蒸气的相互作用。 与溶液体系相比,基于试纸的固态化学发光时间可以延长至8~10 min。 该方法对草酰氯蒸气的检测限较低,分别为0.013 mg/m³(PF)、0.27 mg/m³(F-T-T-F)和1.8 mg/m³(3FT-BTD)。 制备的检测试纸可以反复暴露于草酰氯蒸气中引发化学发光,发光强度没有明显的降低,说明试纸有很好的重复使用性。 由于该试纸对草酰氯有选择性的作用,因此可以对毒性草酰氯气体进行简便的可视化检测。     

Novel Surface-Enhanced Fluorescence D Etection of Polynuclear Aromatic Hydrocarbons Separated by Paper Chromatography

Abstract

Amorphous famed silica was used to enhance the fluorescence signal of a mixture of polynuclear aromatic (PMA) compounds separated by paper chromatography. Benzo[a]pyrene-r-7, t-8, 9, 10-tetrahydrotetrol (BPT) and benzo[a]pyrene (BaP) were well resolved by paper chromatography using a 50% (v/v) mixture of acetonitrile and 5 mM pH 7.0 phosphate buffer as the chromatographic solvent. A 200–400% enhancement of the fluorescence intensity was observed when fumed silica was applied to the chromatographic paper prior to separation. the results demonstrate that paper chromatography using fumed silica treated paper offers a simple, cost-effective method to improve sensitivity for fluorescence detection of PNA components in environmental samples relative to untreated paper.     

Relationship between the decrease of degree of polymerisation of cellulose and the loss of groundwood pulp paper mechanical properties during accelerated ageing

During natural ageing, paper undergoes colour changes and becomes brittle. It is mainly due to the degradation of cellulose, the main component of paper fibres. From the viewpoint of conservation/protection of paper-based information carriers, as well as of the utilisation of secondary fibres, knowledge of the impact of a decrease of the degree of polymerisation (DP) of cellulose on mechanical properties of paper becomes of key importance. In this paper, correlations between the decrease of DP of cellulose and the loss of paper folding endurance (FE) using three model samples (pure cellulose, groundwood pulp paper, and degraded groundwood pulp paper) at accelerated ageing were investigated. The existence of such correlations between DP and FE is supported by experimental results; the correlations are linear for pure cellulose and groundwood pulp paper ageing, while exponential correlation was observed in case of degraded groundwood pulp paper. The results indicate that the rate of paper degradation can be evaluated by means of the rate of glycosidic bonds breaking in cellulosic polymer chains both for cellulose and groundwood pulp paper.     

Reversed-phase partition chromatographic separations with 2-ethylhexyl dihydrogen phosphate and di-2-ethylhexyl hydrogen phosphate

Di-2-ethylhexyl hydrogen phosphate (HDEHP) and 2-ethylhexyl dihydrogen phosphate (H(2)MEHP) are compared as stationary phases in reversed-phase chromatography of selected lanthanides, strontium, yttrium, barium, manganese(II), iron(III), cobalt(II), nickel, gold(III), platinum(IV), palladium(II) and silver. Chromatograms were mainly developed with hydrochloric acid at various concentrations. In general H(2)MEHP was found to be less satisfactory than HDEHP. Development of chromatograms by dilute aqueous electrolytes on paper is slower and separations of chemically similar metals such as lanthanides is not encouraging. However, movement of lanthanides by EDTA at pH 3 in an aqueous sodium perchlorate medium occurs only on H(2)MEHP-treated paper. Good separations of iron(III) and cobalt(II) are possible on paper treated with either ester, and gold(III) and platinum(IV) are separated on HDEHP-impregnated paper. Column methods for the separation of carrier-free gold-199 and iron-59 from macro-amounts of neutron-irradiated platinum and cobalt, respectively, have been developed.     

Low Cost Layer by Layer Construction of CNT/Chitosan Flexible Paper‐based Electrodes: A Versatile Electrochemical Platform for Point of Care and Point of Need Testing

Modification of cellulosic paper with carbon nanotubes (CNT) was studied for the development of electronic and analytical devices. Interesting results were published by using a CNT aqueous solution and the capillary forces of filter paper to make conductive tracks, supercapacitors, potentiometric electrodes and chemometric sensors. In this report, we show for the first time an electrochemical characterization of CNT‐CS‐SDS paper electrodes constructed with an ink containing optimized proportions of multi‐wall CNT, chitosan (CS) and sodium dodecyl sulfate (SDS), and we compared our data with CNT‐SDS paper electrodes constructed with a previously reported ink. We achieved better reversibility (ΔE=131±14 mV, CVs) and reproducibility (RSD=3.63 %) with CNT‐CS‐SDS paper electrodes, when compared to CNT‐SDS paper electrodes (ΔE=249±7 mV; RSD=6.8 %) used as controls. When electrodes were fold at 90° angle, CNT‐CS‐SDS paper electrodes showed lower RSD than CNT‐SDS paper electrodes, 8.43 % and 21.5 % respectively. These results are in concordance with SEM analysis indicating a dense CS film in CNT‐CS‐SDS paper electrodes. As a proof of concept, we determine dopamine concentration by DPV in the presence of ascorbic and uric acids, the limit of detection calculated was 6.32 μM. Moreover, a bismuth‐film was prepared by in situ plating of Bi into CNT‐CS‐SDS paper electrodes. ASV allowed us to detect Pb in the presence of Bi (10–200 ppb) with a limit of detection of 6.74 ppb.     

A simple in situ visual and tristimulus colorimetric method for the determination of trace arsenic in environmental water after its collection on a mercury(II)-impregnated paper.

A simple in situ visual and tristimulus colorimetric method for the determination of trace arsenic in environmental water after collecting arsenic on a test paper impregnated with mercury(II) bromide and rosaniline chloride by its reduction aeration has been developed. The color development on the test paper is based on the formations of AsH(HgBr)2 (yellow) and/or As(HgBr)3 (brownish yellow) by a reaction between mercury(II) bromide and arsine (AsH3), which is produced through the reduction of As(III) (arsenite ion) and/or As(V) (arsenate ion) in a sample solution. To a sample solution, potassium iodide, tin(II) chloride, zinc sand and 4 ml of 6 M hydrochloric acid solution were added successively. The liberated arsine was collected on the test paper. The yellow or brownish-yellow color intensity on the test paper was measured by a tristimulus colorimeter and also by a visual method. The established method is applicable to the determination of arsenic in environmental water sample such as river, brackish, and seawater types.     

高分辨气相色谱/质谱法分析新闻纸和复印纸中的二恶英

随机选择空白的和经过印刷的新闻纸和复印纸,粉碎后用溶剂提取并经多步色谱柱纯化,采用同位素稀释、高分辨气相色谱/高分辨质谱(HRGC/HRMS)联用技术分析了其中的二含量。结果表明:新闻纸中二的总量高于复印纸,但是毒性当量却低于复印纸;经过印刷的新闻纸和复印纸中二的含量均高于空白的新闻纸和复印纸;新闻纸和复印纸中相同二异构体的含量 是不同的。空白的和经过印刷的新闻纸中二毒性当量分别为0.48 ng/kg和0.61 ng/kg,而空白的和经过印刷的复印纸中二恶英毒性当量分别为0.74 ng/kg和0.79     

高分辨气相色谱/质谱法分析新闻纸和复印纸中的二噁

随机选择空白的和经过印刷的新闻纸和复印纸 ,粉碎后用溶剂提取并经多步色谱柱纯化 ,采用同位素稀释、高分辨气相色谱 /高分辨质谱 (HRGC/HRMS)联用技术分析了其中的二含量。结果表明 :新闻纸中二的总量高于复印纸 ,但是毒性当量却低于复印纸 ;经过印刷的新闻纸和复印纸中二的含量均高于空白的新闻纸和复印纸 ;新闻纸和复印纸中相同二异构体的含量是不同的。空白的和经过印刷的新闻纸中二毒性当量分别为 0 4 8ng/kg和 0 6 1ng/kg,而空白的和经过印刷的复印纸中二毒性当量分别为 0 74ng/kg和 0 79ng/kg。所有样品中添加的13 C标记的 2 ,3,7,8位取代的二回收率均在 4 9 82 %至 131 34%之间。     

Total synthesis of scytophycin C. 2. Coupling reaction of the C(1)-C(18) segment and the C(19)-C(31) segment, a key macrolactonization, and the crucial terminal amidation reaction

[reaction: see text] Stereoselective syntheses of the C(1)-C(18) segment (segment A) and the C(19)-C(31) segment (segment B) are described in the preceding paper. This paper reports the key coupling reaction of both segments, 22-membered lactonization, and the crucial terminal amidation reaction culminating in the total synthesis of scytophycin C.     

Solution processed aluminum paper for flexible electronics

As an alternative to vacuum deposition, preparation of highly conductive papers with aluminum (Al) features is successfully achieved by the solution process consisting of Al precursor ink (AlH(3){O(C(4)H(9))(2)}) and low temperature stamping process performed at 110 °C without any serious hydroxylation and oxidation problems. Al features formed on several kinds of paper substrates (calendar, magazine, and inkjet printing paper substrates) are less than ～60 nm thick, and their electrical conductivities were found to be as good as thermally evaporated Al film or even better (≤2 Ω/□). Strong adhesion of Al features to paper substrates and their excellent flexibility are also experimentally confirmed by TEM observation and mechanical tests, such as tape and bending tests. The solution processed Al features on paper substrates show different electrical and mechanical performance depending on the paper type, and inkjet printing paper is found to be the best substrate with high and stable electrical and mechanical properties. The Al conductive papers produced by the solution process may be applicable in disposal paper electronics.     

Paper‐based Electrochemical Devices Coupled to External Graphene‐Cu Nanoparticles Modified Solid Electrode through Meniscus Configuration and their Use in Biological Analysis

This paper demonstrates, for the first time, the use of paper‐based electrochemical devices coupled to external solid working electrodes. The paper‐based electrochemical cells were fabricated using inexpensive and largely available office paper, according to a simple protocol that consists on the creation of hydrophobic barriers using paraffinized paper and preheated metal stamp. The counter and reference electrodes were integrated to the paper platform through the deposition of carbon and silver inks, respectively. The electrochemical paper analytical device (ePAD) was coupled to external glassy carbon rod electrode modified with reduced graphene oxide doped with Cu nanoparticles through meniscus configuration. The analytical usefulness of this electrochemical approach was demonstrated through the simultaneous determination of paracetamol and caffeine in biological samples. The analytes were successfully quantified in real urine samples and limits of detection of 24.6 nM (paracetamol) and 36.1 nM (caffeine) were obtained. The paper platform showed good stability (RSD of 1.07 % for the peak currents and 1.43 % for the peak potentials) and satisfactory performance. The use of solid electrodes coupled to paper electrochemical devices, firstly demonstrated here, opens new possibilities for the utilization of ePADs in electrochemistry and electroanalytical chemistry and offers advantages such as the extremely reduced consumption of reagents and the minimal generation of wastes.     

Conductive paper through LbL multilayering with conductive polymer: dominant factors to increase electrical conductivity

A conductive paper was made of cellulose fibers with a multilayer of polyethyleneimine (PEI) and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) and the factors to increase the conductivity of the paper were investigated. The adsorption amount and the structure of PEI and PEDOT:PSS multilayer was changed by controlling salt concentration and the number of layers, and inter-contact degree of fibers was controlled by calendering. The adsorption behavior of the polyelectrolytes onto cellulose was evaluated using a quartz crystal microbalance with dissipation monitoring, and the adsorption amount was quantitatively analyzed through Kjeldahl nitrogen analysis and an Inductively Coupled Plasma Optical Emission Spectrometer. The conductivity of the resultant paper was in the range of 10^?5–10^?4 S/cm without loss of paper strength. The conductivity of the paper increased when the multilayer was formed at low salt concentration and the conductive paper was calendered. It appeared that electron transfer by increased contact between PEDOT:PSS improved the conductivity of the paper.     

Grafting of cyclodextrins onto filter paper

Grafting of cyclodextrins and cyclodextrins derivatives on cellulosic surface, such as paper or filter paper, provides hosting cavities that can include a large variety of chemicals for specific cellulose finishing. In this study grafting of monocholorotriazinyl-β-cyclodextrin (MCT-β-CD) and β-cyclodextrin (β-CD) to filter paper has been performed. β-cyclodextrin has been bonded to filter paper using 1,4-butanediol diglycidyl ether as the crosslinking agent. The untreated and treated filter papers were characterized by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), demonstrating the covalent binding of cyclodextrins to filter paper. The quantification of β-CD and MCT-β-CD grafted to filter paper was determined by the dye extinction method with the inclusion of phenolphthalein. The final β-CD content amounted to 15.9 μmol per gram of support (1.8% by weight), and 72.8 μmol per gram of support (11.3% by weight) for MCT-β-CD.     

Thin Layer Chromatographic Systems for the Classification and Identification of Antibiotics

Abstract

Several comparative chromatoqraohic systems described in the literature may he useful for facilities dealing with a relatively large number of different antibiotics, such as clinical laboratories engaged in the identification of antbiotics in human serum; research laboratories screening for new antbiotics; and regulatory agencies testing drug preparations. Ishida et al. (1) introduced the “summarized paper chromatogram” which is obtained when R_f values computed from several solvent systems are represented graphically. Retina (2) classified 62 antibiotics on the basis of graphical representation using paper chromatographic techniques. Later Betina and Nemec (3) used paper chromatography (PC) with buffered solutions for the classification of antibiotics. Snell et al. (4) used paper chromatographic classification of antibiotics in crude preparations.     

Development of a detection tablet for a portable NO2 monitoring system.

We have already developed a HCHO monitoring system which is called FP-30. In this experiment, we have developed a NO(2) detection tablet which can be used by the monitoring system. The detection tablet for the NO(2) was constructed with the sensing paper: porous cellulose paper that contains silica gel as an adsorbent, N-1-naphthylethylenediamine dihydrochloride (NED), and glycerin. The NO(2) in sample gas was blown over and adsorbed on the surface of the sensing paper. Then the NO(2) reacted with NED, producing a yellow compound. The coloring reaction took place on the surface of the sensing paper. The degree of color change of paper from white to yellow was monitored as a function of the intensity of the reflected light (lambda = 475 nm) of an LED. The detection limit was 0.01 ppm when the sampling time was 30 min, and the flow rate of sample gas was 250 ml/min. This sensing paper process was not interfered with by acetaldehyde, acetone, alcohols, hydrocarbons, carbon monoxide or carbon dioxide. The NO(2) concentrations in the rooms of a house or school were monitored using this monitoring system and the standard chemiluminescence method. The concentrations of NO(2) monitored by both methods were within 18% of the average. This highly sensitive, selective, and handy NO(2) gas monitoring system will be widely applicable and convenient for users who are not specialists in this field.     

Properties of silver nanoparticle-polypyrrole composite film grown on cellulosic paper

Cellulose - In this work, a cellulosic paper substrate (Pap) coated by in situ polymerization of polypyrrole (PPY) was designed. This paper was subsequently coated with silver nanoparticles...     

Evaluation of the effect of cleaning on the morphological properties of ancient paper surface

In the conservation field, the original morphology and texture of the paper surface represent an important aspect to be preserved as historical evidence of the papermaking process. The aim of this preliminary research is to evaluate the effects of aqueous (cellulose ethers, rigid gels of Agar and Gellan gum) and not aqueous cleaning treatments (a typical dry cleaning treatment with wishab sponge) on the original surface morphology of late nineteenth century paper. Nineteenth century newspaper paper was chosen because it is strongly affected by cellulose oxidation and depolimerization due to the rough materials (wood pulp) and the papermaking process used at the time and to the environmental conditions (light, humidity, temperature) to which such paper has been subjected. A preliminary characterization of the paper with Herzberg and Phloroglucinol reactives and Fourier Transform infrared Spectroscopy analysis was performed to understand the paper composition and the type of inorganic fillers used. The paper surface microtopography was then measured by contact profilometry to analyze the effects of the cleaning treatments on paper surface roughness. The effects of the cleaning action was qualitatively evaluated by means of stereo microscopy and scanning electron microscopy. Preliminary results suggest that the treatments which are most respectful of the original surface micromorphology of the paper are those based on the use of rigid gels (Agar and Gellan gum), because they determine the smallest variation in the roughness of surface paper, unlike the application of cellulose ethers by brush. This finding was confirmed by statistical analysis of the roughness results by means of ANOVA and Tukey HSD post hoc test.     

Preparation and physical properties of superhydrophobic papers

In this study, we developed a facile method for preparing a superhydrophobic paper surface using a multi-layer deposition of polydiallyldimethylammonium chloride (polyDADMAC) and silica particles, followed by a fluorination surface treatment with 1H,1H,2H,2H-perfluorooctyltriethoxysilane (POTS, CF(3)(CF(2))(5)CH(2)CH(2)Si(OC(2)H(5))(3)). The superhydrophobic wood fiber products prepared in this study have contact angles of water greater than 150 degrees and sliding angles less than 5 degrees. Besides their high water repelling property, the superhydrophobic paper products kept a high tensile strength at high relative humidity condition. The superhydrophobic paper products also showed high resistance to bacterial contamination.