Papermaking Technique Research Articles

Analytical modelling of the behaviour and scatter of the flexural modulus of randomly oriented carbon fibre strand thermoplastic composites

Randomly oriented strand composites are promising materials for complex-shaped parts, especially in the aerospace and automotive industries. However, test data from small specimens tend to have a high level of scatter as these materials contain several centimetres of chopped carbon fibre strands. In this study, we investigated the mechanical properties of ultra-thin chopped carbon fibre tape reinforced thermoplastics (UT-CTT), which contain chopped thermoplastic thin-ply prepreg tapes produced using a paper-making technique. We propose a model for accurately evaluating the flexural modulus and its scatter, which was verified by comparison with experimental data. The predictions of the model showed excellent agreement with the experimental results. This method makes it possible to quantify the scatter of the flexural modulus and is useful for designing geometries of, not only standard test specimens, but also complex parts for actual applications.

Analysis of compiling date of Huang di nei jing (Huangdi's Internal Classic)

There are Seven Medical Classics recorded in the Han shu Yi wen zhi(Bibliography in Annals of the Han Dynasty), among which the 18-volume Huang di nei jing (Huangdi's Internal Classic) is not the current edition of Ling shu (Miraculous Pivot) and Su wen(Plain Questions). The present edition of Huang di nei jing containing these two works might be merged in the Eastern Han Dynasty, benefited from the invention of Cai Lun's papermaking technique and the development of Nine needles, especially filiform needle manufacturing. Huang di nei jing was compiled on the basis of two major integrations: The first was joined by some medical experts such as Bian Que and tai yi ling (minister of imperial physicians) of the Qin State by using the language in the Warring States, contributing mainly to the theoretical system and forming its basic academic framework; The second was the second Royal book-collating activity in the Eastern Han Dynasty (100-110), which had revised the seven volumes of Chinese Medical Classics and incorporated them into two parts, Ling Shu and Su Wen, together with Bian Que's medical works and the new contents from the introductory Chapter on Nine Needles and Twelve Yuan(origin) Acupoints.

Composite Paper Sheet Containing TiO2-diatomite for Removing Phenol in Aqueous Solution

Composite paper sheet containing titanium dioxide and diatomite (TiDI) was prepared via a papermaking technique. The composite sheet was applied to remove phenol from aqueous solution. The composite sheet with a 2:1 mass ratio of cellulosic-fiber to TiDI removed phenol more effectively under UV irradiation than the composite paper sheet that utilized titanium dioxide (TiO2) alone. Composite paper sheets that contained TiDI with a TiO2/diatomite mass ratio of 1:2 removed phenol most effectively. The results showed that the TiDI composite paper could serve as a functional material to photodegrade phenol from aqueous solution under UV irradiation effectively.

Multilayer-stacked paper-structured catalysts for microflow Suzuki–Miyaura cross-coupling reaction

Paper-like porous composites of ceramic fibers and ZnO whiskers were prepared using a papermaking technique, followed by the in situ synthesis of a Pd catalyst on the ZnO whiskers using a facile impregnation method. The flexible Pd@ZnO papers had micrometer-sized pores of average diameter ca. 25 μm, which promoted the effective diffusion of reactants passing through an assembly of vertically stacked papers in a flow reactor. The catalytic efficiency of the stacked Pd@ZnO papers in a flow Suzuki–Miyaura cross-coupling (SMC) reaction to synthesize 4-methylbiphenyl from phenylboronic acid and 4-iodotoluene was higher than that of a bead-type Pd particulate catalyst in a reactor. Microchannels originating from the porous fiber-network microstructures in the stacked papers contributed to effective heterogeneous catalysis, possibly by enabling smooth diffusion of substrates to the surfaces of the Pd catalysts, as in a microreactor system. K2CO3, which was used as the base in the SMC reaction, was also immobilized in the paper-structured fibrous composites. Stacks of two types of paper, i.e., containing either Pd catalysts or K2CO3, significantly affected the SMC catalytic activity in a continuous microflow reaction. A combination of K2CO3 papers upstream and Pd@ZnO papers downstream in the flow system provided higher catalytic efficiency via on-site K2CO3-mediated borate formation of phenylboronic acid in the initial stage in the reactor. Tailoring of the stacking patterns of the paper-structured composites is expected to be effective for sequential SMC reaction and to improve catalytic process engineering.

Catalytic paper made from ceramic fibres and natural ulexite. Application to diesel particulate removal

Ceramic paper discs were made by employing a dual papermaking technique and by partially substituting cellulosic fibres by SiO2-Al2O3 ceramic ones. Ulexite (NaCaB5O6(OH)6·5(H2O)), extracted from the natural mineral, was added as a binder to give ceramic paper the necessary strength for its manipulation and catalytic use.Either La,Co or Ba,Co was incorporated in order to give ceramic paper the capability of trapping NOx and oxidizing soot particles. Structured catalysts were characterised by SEM, FTIR and XRD, and the mechanical properties were also determined. Lanthanum was deposited on ceramic fibres as La2O2CO3 aggregates and barium as BaCO3 filaments, being cobalt deposited as Co3O4 flakes. Mechanical properties indicated that the ceramic paper obtained from natural ulexite proved to be stronger, though less flexible than those prepared using colloidal suspensions as a binder.Diesel soot oxidation activity was determined by TPO either adding or not 0.1% NO into the feeding stream. The thus prepared systems resulted in being active towards soot oxidation, being the value of maximum combustion rate 420°C, which is within the temperature range of diesel exhaust gases.

Paper-structured Catalysts with Porous Fiber Networks for Fischer-Tropsch Synthesis

The Fischer-Tropsch synthesis (FTS) is a promising catalytic process for converting syngas (hydrogen and carbon monoxide (CO)) into valuable hydrocarbons for use as fuels and fine chemicals. However, the FTS reaction is highly exothermic; hence careful process control is required to promote smooth gas flow and avoid the formation of local hot spots inside the catalyst layer. In this work, cobalt (Co)-based paper-structured catalysts with micrometer-size pores were prepared via a papermaking technique and an impregnation method. The FTS reaction was carried out using Co-containing paper composites having different Co loadings, residence times and stacking patterns to investigate the effects of the catalyst layer design on the FTS catalytic efficiency. Catalytically-active metallic Co nanoparticles were successfully synthesized inside the porous fiber networks of the flexible and easy-to-handle paper composites. An alternate stacking arrangement of five Co papers and a designated number of catalyst-free ceramic papers demonstrated higher CO conversion than stacks of the Co papers alone without ceramic spacing layers, despite the same total Co loading and gas residence time inside the catalyst layers. It was assumed that the catalyst-free ceramic papers with porous fiber networks effectively promoted the diffusion of both gas and heat during the exothermic FTS processes. Our paper-structured catalysts with a unique porous architecture allowed fine-tuning of the catalyst layers by stacking the various paper composites. These results are expected to advance catalytic FTS process engineering.

Solvent-free alcohol oxidation using paper-structured catalysts: Flow dynamics and reaction kinetics

Paper-structured fibrous composites with micrometer-sized pores were prepared using a papermaking technique, followed by in situ synthesis of Pd nanoparticles in the paper matrix using a facile impregnation method. The Pd-containing paper-structured catalysts showed high catalytic activities in solvent-free benzyl alcohol oxidation in a flow reaction system. Highly selective oxidation was achieved using the porous paper-structured catalysts set inside a gas–liquid–solid multiphase reactor. Kinetic and mechanistic studies of various reactions showed that the catalytic activity and selectivity were associated with microfluidic behavior in the fiber-network pores. A uniform distribution of the liquid-phase substrate, i.e., benzyl alcohol, provided high catalytic activity. High selectivity for the oxidation pathways can be attributed to efficient gas–liquid–solid mass transfer toward the thin liquid layer formed at the interface between the alcohol and Pd catalyst inside the porous fiber networks.

Effect of beating revolution on dispersion of flame attenuated glass wool suspension and tensile strength of associated glass fiber wet-laid mat

Beating is the most significant process in papermaking technique that can modify the fiber morphology, sheet-formation ability of fiber suspension and properties of the wet-laid mat. In this paper, flame attenuated glass wool was beaten in water at various revolutions, ranging from 1500r to 12000r. Compared to suspensions beaten at 0r and 1500r where glass fibers simply aggregated in water, glass wool suspensions beaten at 3000r to 8000r were homogeneous with separated and randomly arranged glass fibers. Further, suspensions beaten at revolutions above 8000r were uniform but with a few broken glass fibers. The dewatering characteristics of fiber suspensions were analyzed based on fiber plugging model. Drainage resistances of flame attenuated glass wool suspension increased dramatically from 22°SR (unbeaten) to 29°SR (at 1500r) and then maintained at this value till 12000r. Density and porosity of the fabricated wet-laid mat was 95kg/m3 and 94%, respectively. Maximum tensile strength of 170N/m for the wet-laid mat was achieved at 8000r, which then decreased significantly to 100N/m when the revolutions exceed 10000r.

Flexible Cellulose-Based Electrodes: Towards Eco-friendly All-paper Batteries

In the present work an easy paper-making technique is used for the manufacture of low cost and low environmental impact all-paper-based Li-ion cells. The cells are composed of two paper-like electrodes, prepared using micrometric-sized graphite (anode) and LiFePO4 (cathode) as active materials and truly natural microfibrillated cellulose as binder, and paper hand-sheets soaked in a standard liquid electrolyte solution as separator between them. The specific capacity obtained is even superior to that of standard PVdF-binded cell assembled with the same electrodes, and remains stable over prolonged cycling, indicating that the cellulose fibres do not affect the cycling stability. In this study, no organic solvents or synthetic polymer binders are used all along the production of the cell components which, in addition, can be easily re-dispersed in water by simple mechanical stirring as well as common paper handsheets.

Multiphase catalytic oxidation of alcohols over paper-structured catalysts with micrometer-size pores

Paper-structured catalysts were prepared using ceramic fibers by a wet papermaking technique, followed by the deposition of ruthenium hydroxide on the fiber-network microstructures. As-prepared flexible paper catalysts possessed large geometric surface areas with micrometer-size pores. The paper-structured catalysts exhibited high catalytic efficiency for selective aerobic oxidation of aromatic and aliphatic alcohols to their corresponding aldehydes and ketones, in a fixed bed multiphase reactor. Hydrodynamic behavior in the reactor filled with either paper or bead catalysts was evaluated by measuring the residence time distribution in a cold flow model. It was revealed that the paper composites exhibited good wettability and internal diffusion of liquid substances compared with ceramic beads, showing heterogeneous liquid flow. Efficient catalytic oxidation of various alcohols was achieved using the paper-structured catalysts because uniform fluid dynamic behavior formed a thin liquid layer on the catalyst surfaces, possibly resulting in favorable gas–liquid–solid interfaces.

Preparation of Catalytic Paper Using Fe-Pillared Bentonite as Filler by a Paper-Making Technique

Fe-pillared bentonite was made into a paper-like composite by a papermaking technique using pulp fiber and activated carbon fiber. Orange II was used as a model compound to investigate the photocatalytic performance of the paper. SEM analysis showed that the catalytic paper had a porous structure originating from the layered fiber network, with Fe-pillared bentonite mostly embedded in the grooves along the axial direction of the carbon fibers. The optimum preparation conditions were: activated carbon fiber:Fe-pillared bentonite=1:2, activated carbon fiber:pulp fiber=5:3, the charges of Na2SiO3 and PAE were 2.5% based on the Fe-pillared bentonite and 0.4% based on the oven-dry fibers, respectively. The degradation ratio reached 85.2% at 180 min and after that little increase was observed. The catalyst could be repeatedly use and keep a high stability during the first 4 cycling use.

Ligno-Cellulosic Materials for the Next-Generation of Eco-Friendly Polymeric Energy Power Sources

In the last 20 years, the Li-ion battery (LIB) market has rapidly grown thanks to the extensive diffusion of mobile electronics devices. The optimisation of existing chemistries by the introduction of environmentally friendly materials and the simplification of the production process are intriguing challenges to promote the future widespread diffusion of LIBs. In order to lower the cost and reduce the environmental impact of LIBs, which is crucial in the perspective of their large-scale diffusion, an effort must be made to reduce the amount of inactive components in the cell, to substitute high cost materials, such as synthetic polymer binders / separators and organic solvents, with low-cost and bio-based/bio-inspired materials and to develop new eco-friendly processes for the manufacture of cell components [1].Nanoscale-microfibrillated cellulose particles (NMFC), first studied by Herrick and Tubark, are easily available and biodegradable; they show stiffness, impressive mechanical properties and reinforcing capability, low weight and, furthermore, their preparation process is easy, low cost and does not involve chemical reactions. They can significantly reinforce polymer electrolytes already at low filler loadings and also replace the commonly used PVdF as binder for self-standing and flexible electrodes, thus serving as a promising candidate for bio-composite production [2-4].In the present work paper-making technique was used for manufacturing low cost bio-inspired all-paper Li-ion cells, constituted by two paper-electrodes, prepared using micrometric size graphite (anode) and LiFePO4 (cathode) as active materials, and paper hand-sheets reinforced polymers as electrolyte. Considering the interesting properties of NMFC and the potentials of free radical photo-polymerisation, a UV cured NMFC-polymer composite membrane could surely result highly promising. Thus, NMFC particles as reinforcement for composite methacrylic/ethylene-oxide based solid or quasi solid polymer electrolyte membranes were also prepared by UV curing. The use of such a filler/binder results extremely interesting, giving the possibility to produce high performing, safe and extremely flexible electrolytes for Li-ion batteries. No organic solvents or synthetic polymer binders are used during the entire electrode/electrolyte/cell preparation process. The all-paper-cell can be easily re-dispersed in water by simple mechanical stirring, as well as common paper hand sheets and paper-battery materials can be recovered using well-known water-based recycling process. Finally, the results of an all-solid paper-cell, comprising methacrylic and/or PEO-based membranes as polymer electrolytes are presented, which demonstrate the possibility of obtaining in the next future “truly green” Li-based energy storage devices.[1] L. Jabbour, R. Bongiovanni, D. Chaussy, C. Gerbaldi, D. Beneventi Cellulose 20 (2013) 1523.[2] L. Jabbour, C. Gerbaldi, D. Chaussy, E. Zeno, S. Bodoardo, D. Beneventi, J. Mater. Chem. 20 (2010) 7344.[3] L. Jabbour, M. Destro, D. Chaussy, C. Gerbaldi, N. Penazzi, S. Bodoardo, D. Beneventi, Cellulose 20 (2013) 571.[4] A. Chiappone, Jijeesh R. Nair, C. Gerbaldi, L. Jabbour, R. Bongiovanni, E. Zeno, D. Beneventi, N. Penazzi, J. Power Sources 196 (2011) 10280.

Preparation of porous paper composites with ruthenium hydroxide and catalytic alcohol oxidation in a multiphase gas–liquid–solid reaction

Abstract In situ synthesis of ruthenium hydroxide catalysts on a microporous fiber-network structure of ceramic paper composites was achieved. The efficient catalytic oxidation of alcohol was investigated in a heterogeneous, multiphase gas–liquid–solid reaction. A simple papermaking technique and subsequent immersion in a ruthenium chloride solution allowed us to fabricate novel-concept microstructured catalysts. The paper-structured catalysts possess micropores ca. 30 μm in diameter with high porosity of ca. 90%. They exhibited much higher catalytic efficiency in the O 2 -mediated oxidation in toluene of benzyl alcohol to benzaldehyde in a fixed bed external loop reactor, as compared with conventional pellet- and bead-type solid catalysts. This excellent catalytic effect is possibly attributed to the porous paper composite microstructure like microreactors.

Ceramic papers as flexible structures for the development of novel diesel soot combustion catalysts

Currently, the most adequate technology for the abatement of particles coming from diesel engines is the one that employs catalytic filters. This work proposes the preparation of catalytic ceramic papers to be employed in the development of new catalytic filters. To this end, the papermaking technique was employed. The resulting papers were flexible, easy to handle and presented suitable mechanical properties to resist the tests from a test bench in which they were placed inside a metal housing, at the exhaust pipe outlet of a Corsa 1.7 vehicle. These optimal mechanical properties were obtained through the incorporation of a suspension of CeO2 nanoparticles during the papermaking process. It was found that the nanoparticles covered the ceramic fibers completely and that their excess accumulated under the form of patches. In order to promote the filter continuous regeneration, once the ceramic papers were formed they were impregnated with a cobalt salt which, after a calcination stage, produced oxidic clusters in tight contact with the CeO2 nanoparticles. The papers thus obtained exhibited a maximum soot combustion temperature close to 400 °C, being T50 = 376 °C for the more active catalytic ceramic paper, in the presence of NO (1000 ppm) in the feed. Even though more tests are necessary to determine filtration efficiency, preliminary experiments carried out in the test bench proved that the ceramic papers properly resisted the high gas flow rates of fumes emitted by a real diesel engine (approximately 2 m3 min−1). From the TPO experiments performed on samples of catalytic ceramic papers taken from the test bench and in tight contact with the soot retained, it was possible to obtain a maximum soot combustion temperature equal to 428 °C. It was also found that the presence of ceria aggregates caused the papers to deactivate to a lesser degree after being treated at 900 °C.

On-Paper Synthesis of Nickel Nanoparticles and Catalytic Propane Steam Reforming for Efficient Hydrogen Production

Nickel nanoparticles (NiNPs) were successfully synthesized in situ on a microstructured paper matrix composed of inorganic fibers as the main framework and zinc oxide (ZnO) whiskers as a preferential support for NiNPs. The paper-like inorganic fiber/ZnO whisker composites were prepared using a high-speed and low-cost papermaking technique, and then simply immersed in an aqueous solution of Ni(NO3)2. After reduction in hydrogen flow, NiNPs with a fine size about 20 nm in diameter were selectively formed on the ZnO whiskers in the paper composites. As-prepared NiNPs@ZnO paper is much like an ordinary paper product, being flexible, lightweight, and easy to handle. The NiNPs@ZnO paper composites exhibited excellent catalytic performance in the steam reforming of propane, and produced hydrogen more efficiently than commercial pellet-type nickel catalysts. These results are possibly attributed both to highly active NiNPs synthesized in situ and to the uniform flow of reactants inside a microporous paper structure.

In situ synthesis of Ni/MgO catalysts on inorganic paper-like matrix for methane steam reforming

In situ synthesis of nickel/magnesium oxides (Ni/MgO) on a microstructured inorganic paper support was investigated to develop high-performance, easily handled, paper-like catalysts, using two different methods: sequential impregnation and co-impregnation approaches. Porous paper supports were prepared beforehand using a conventional papermaking technique, and then simply impregnated with Mg(NO3)2 and Ni(NO3)2 solutions, either stepwise or at the same time. After reduction in a hydrogen flow, Ni/MgO catalysts were formed in the paper composites. The as-prepared Ni/MgO paper is much like an ordinary paper product, being flexible, lightweight, and easy to handle. The Ni/MgO paper composites, especially the co-impregnated paper, exhibited excellent catalytic performances in the steam reforming of methane, and produced hydrogen much more efficiently than did commercial Ni-based catalysts in powdered and pellet forms. The Ni/MgO paper composites also showed good durability for 24-h continuous reaction, and maintained their initial efficiency for methane steam reforming. These results were attributed to the favorable supply of gaseous reactants to the active Ni/MgO catalysts, which were well distributed inside a microporous paper structure.

Direct Synthesis of Gold Nanocatalysts on TEMPO-oxidized Pulp Paper Containing Aldehyde Groups

In situ synthesis of gold nanoparticles on paper sheets was achieved without any external reducing reagents and heat treatments. Surface-activated pulp fibers with carboxyl and aldehyde contents of 1.18 and 0.349 mmol g–1, respectively, which were obtained from softwood kraft pulp using 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO), were fabricated into paper sheets with polyamideamine epichlorohydrin (PAE) resin with a papermaking technique. The TEMPO-oxidized pulp papers were flexible, lightweight, and easy to handle in a wet state due to the PAE-mediated reinforcement. Simple immersion of the white TEMPO-oxidized paper in an aqueous solution of tetrachloroauric acid at room temperature brought about distinct color change from white to red-purple, strongly suggesting the formation of gold nanoparticles. Post-oxidized aldehyde-free paper provided no color variation, and thus the aldehyde groups on pulp fibers made a significant contribution to the in situ synthesis of gold nanoparticles. The organic–inorganic paper materials of TEMPO-oxidized pulp and gold nanoparticles demonstrated the catalytic activity for the reduction of 4-nitrophenol to 4-aminophenol in an aqueous system.

Photocatalytic behavior of cellulose-based paper with TiO2 loaded on carbon fibers

Cellulose-based photocatalytic paper was prepared with a papermaking technique, in which TiO2 nanoparticle loaded carbon fibers were used together with cellulose fibers as raw materials. TiO2 nanoparticles were loaded on carbon fibers with either Na2SiO3 or Al2(SO4)3 as adhesive. They are distributed on carbon fibers in a form of small clusters. The photodegradation behaviors of the as-prepared papers were investigated using methyl orange (MO) solution as a target pollutant. It was found that the degradation effects of papers on MO using sodium silicate as the adhesive of TiO2 nanoparticles are higher than those using aluminum sulfate as adhesive. When the ratio of carbon fiber to cellulose fiber is 1:1, the photocatalytic paper exhibits a high degradation performance. The introduction of poly(amideamine-epichlorohydrin) (PAE) as a paper wet strengthening agent had no significant influence on the photocatalytic activities of paper. In addition, the photocatalytic paper exhibits quite stable photocatalytic activity under UV-light irradiation and can be used repeatedly. The simple procedure is promising for the manufacture of paper with high photocatalytic activity.

Catalytic and Optical Properties of TiO<SUB>2</SUB> Photoactive Nanopaper Prepared by Using the Wet-End Papermaking Technique

Catalytic and Optical Properties of TiO<SUB>2</SUB> Photoactive Nanopaper Prepared by Using the Wet-End Papermaking Technique

Highly transparent and writable wood all-cellulose hybrid nanostructured paper

Paper, as an inexpensive substrate for flexible electronics and energy devices, has garnered great attention because of its abundance, biodegradability, renewability and sustainability. However, the intrinsic opacity and higher roughness of regular paper greatly restricts further applications. One promising method is to use cellulose nanofibers (CNs) to fabricate nanopaper with a high optical transmittance and excellent smoothness, but there are still some challenges facing nanopaper substrates, such as high-energy consumption to extract nanofibers and the time-consuming process to prepare nanopaper. We design a bilayer hybrid paper using unbeaten wood fibers and CNs with a papermaking technique, which achieves a high optical transmittance and superior smoothness while remaining less expensive than nanopaper and useful as a writable surface. The first transparent paper touchscreen with an excellent anti-glare effect in bright environments is demonstrated using our novel transparent and conductive hybrid paper as the flexible electrode.