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The morphological properties and particle size characteristics of micro- and nanofibrillated cellulose (NFC) and lignin-containing NFC (LNFC) produced by a microfluidizer processor were investigated. The effects mechanism of lignin-containing on the adsorption of NFC and the stable properties of organic dyes suspension were also studied. The results showed that the preparation process and final performance of NFC were affected by the key factors including lignin, homogenization pressure, and number of homogenization cycles. The increase in the homogeneity of the fibrillated cellulose was minor for the NFC samples, while LNFC samples showed a larger increase in the homogeneity of the particle size distribution. The influence of lignin was reflected both in improved fibrillation efficiency and in the final organic dye dispersion properties achieved by LNFC addition, primarily observed as deceased particle sizes and fibril dimensions. This study indicated that pollution-free dispersion of organic dyes can be realized through the application of lignin-containing NFC.

Superhydrophobic surfaces have high potential in self-cleaning and oil-water separation applications. We developed a three-step method for the preparation of superhydrophobic filter paper. It involved citric acid (CA) pretreatment to activate cellulose fibers, coating with cellulose nanofibrils/functionalized silica (CNFs/m-SiO2) slurry to increase surface roughness, and grafting of hexadecyltrimethoxysilane (HDTMS) to enhance water resistance. The water contact angle (WCA) and siding angle (SA) of the prepared filter paper reached 151.5° and 7.5°, respectively. The results showed that, compared to the coated filter paper without the added CNFs, the coated paper with CNFs had higher retention of m-SiO2, thus roughness required for superhydrophobic surface was achieved. Further test under frequent abrasion and acid or alkali conditions showed that CA pretreatment improved the durability of superhydrophobic filter paper due to chemical crosslinking between the modified substrate and m-SiO2. Besides, the prepared superhydrophobic filter paper had outstanding self-cleaning property and high oil-water separation efficiency for various oil-water mixtures. Therefore, it is expected to be used for the treatment of oily wastewater.

It is desirable to develop biodegradable ultraviolet (UV)-shielding materials from renewable resources, as the demand for sustainability is ever increasing. In this work, a novel lignin-TiO2 UV-shielding composite was synthesized successfully via a hydrothermal method induced by nanofibrillated cellulose (NFC). Comprehensive characterization showed that the lignin-TiO2@NFC composite induced by NFC had good nanoparticle size, shape, and thermal stability. The sunscreen performance of lignin-TiO2@NFC was investigated via mixture with unmodified hand cream. The UV-visible (vis) transmission spectra results revealed that the unmodified cream with 10 wt% lignin-TiO2@NFC absorbed approximately 90% of UV light in the full UV band (200 nm to 400 nm), which indicated that lignin-TiO2@NFC had a good UV-shielding ability.

To investigate the high phenolic lignin extraction process, deep eutectic solvents based on oxalic acid and glycerol as a hydrogen bond donor were first prepared and analyzed. Two different types o...

Clogging is a critical problem that restricts the delamination of fibers in a high-pressure homogenizer (HPH). In this work, bleached bamboo pulp fibers were pretreated in TEMPO/NaBr/NaClO system prior to high-pressure homogenization to study the clogging condition in a high-pressure homogenizer. Effects of the additional amount of NaClO on the functional groups and morphologies of the bamboo pulp fiber were evaluated by conductometric titration, Fourier transform infrared spectroscopy (FTIR), fiber morphology analysis, and scanning electron microscopy (SEM). The fiber morphology analyzer revealed that the addition of NaClO facilitated to reduce the length of the fiber. The SEM images showed that TEMPO-mediated oxidation had a destructive effect on the fiber surface. The carboxylate contents of bamboo pulp fibers increased with the addition of NaClO, which were beneficial for increasing the critical concentrations of suspensions in the HPH. Nanocelluloses were successfully isolated from the TEMPO-oxidized bamboo pulp with different clogging critical concentrations, as were revealed by atomic force microscopy (AFM).

A three-component flame-retardant system was prepared based on in situ polymerization of ammonium polyphosphate (APP), diatomite (DE), and aluminium trihydroxide (ATH) to improve the flame retardance and smoke suppression properties of fibrous materials. Compared to the two-component system of APP-DE, the addition of APP-10% DE-4% ATH dosed at a filler load of 20% of the fibrous material reached a limited oxygen index of 27.5%, which was approximately 9.1% higher than the two-component system. The lower mass loss rate and higher residual mass at high temperatures resulted in excellent flame retardance. The synergistic effect on alleviating combustion and reducing heat release was shown by the 16.6%, 22.1%, and 12.5% decreases in the peak heat release rate, total heat release, and average effective heat combustion, respectively. Superior fire resistance was demonstrated by a higher fire performance index and a lower mass loss. A smoke suppression effect was shown by the peak smoke release rate and the total smoke release results that were 28.7% and 15.8% lower than the two-component system, respectively. Based on the porous structure of DE and generated aluminum oxide (Al2O3), the outstanding adsorption effect and flame-retardant effect was also demonstrated by the production rate of carbon monoxide (CO) and carbon dioxide (CO2).

Four flame retardants and styrene-acrylic latex were used to make flame-retardant air filter paper via emulsion impregnation. The compositions and flame retardant mechanism of the flame retardants were investigated by using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). The flame retardance of air filter paper was evaluated using TGA and limiting oxygen index (LOI) meter, and the physical properties and pore structure of the flame-retardant air filter paper were measured using stiffness tester, burst tester, and aperture analyzer. The results showed that the optimal ratio of flame retardant to styrene-acrylic latex was 1:1.4. The synergistic effect of boron, phosphorus and nitrogen made FR3 have good flame-retardant effect on air filter paper. Air filter paper with FR3 also had good physical strength and suitable pore size distribution.

In order to study the property of lignin-based porous carbon activated by potassium tartrate, the effects of activator types, activator/lignin mass ratio and activation temperature on the surface morphology, specific surface area and pore size distribution of alkali lignin based porous carbon materials were systematically investigated. Meanwhile, the methyl orange adsorption capacity and adsorption kinetics of the lignin-based porous carbon were also evaluated. The N2 adsorption-desorption experiment results showed that the specific surface area value of lignin-based porous carbon materials activated by potassium tartrate (APC-J), KOH (APC-K), and NaOH (APC-Na) are 947, 1113 and 762 m2/g, respectively. Meanwhile, APC-J has a special microporous structure, while the pore structures of APC-K and APC-Na are mainly mesopores. The best specific surface area of lignin-based porous carbon materials was 1911 m2/g obtaining from APC-J-2-8 sample (mass ratio 2:1, activation temperature 800 °C). The adsorption experiment of methyl orange (MO) showed that the adsorption kinetics of APC-J-2-8 conformed to the quasi-second-order kinetic model, mainly chemical adsorption. The isothermal adsorption process conforms to the Langmuir adsorption isothermal adsorption model, which is a single molecular layer adsorption, and the maximum adsorption amounts are 526.31 mg/g.

Ammonium polyphosphate–diatomite composite filler (APP-diatomite composite filler) was modified with silane coupling agent KH550 to improve the flame retardancy of filled paper. Cone calorimeter was used to analyze the heat and smoke releasing rates, as well as smoke toxicity of the filled paper. The distribution of the composite filler particles in paper and the morphology of the charred residues after combustion were investigated by scanning electron microscope (SEM), and the chemical structure of the charred residues was studied with fourier transform infrared spectroscopy (FTIR). Results show that the peak heat releasing rate (PHRR), total heat release (THR) and peak mass loss rate (PMLR) of the filled paper with the modified APP-diatomite decreased markedly, compared with those for the control paper, while the charred residue after combustion increased. In addition, the filled paper had an increased peak rate of smoke release (RSR) and increased total smoke release (TSR) and peak CO production rates, but a decreased peak CO 2 production rate. It was also found that part of the carbon element in the charred residue of the paper loaded with the modified APP-diatomite was in the forms of C=C=C, C≡C and C≡N, and the charred residue had a relatively more intact structure without apparent fiber breakage and longitudinal cracks.

Fiber classification of aramid fibrids was carried out using a Bauer-McNett fiber classifier, and the molecular weight and thermal properties of different sizes of aramid fibrids were determined with viscometry and differential scanning calorimetry (DSC), respectively. Aramid handsheets were made from different sizes of aramid fibrids and aramid short fibers, and the relationship between mechanical strength of aramid handsheets and thermal properties of aramid fibrids was examined. In addition, aramid papers from four different sources were also investigated to elucidate the relationship between their thermal properties and mechanical strength. It was found that aramid fibrids passing through 30-mesh screens and remaining on 50-mesh screens and aramid fibrids with narrower molecular weight distribution are suitable for the production of high-strength aramid papers. Lower crystallinity and wider molecular weight distribution are important contributors to the lower mechanical strength of domestic aramid paper when compared to that of Nomex paper.

Silk mask paper with different adsorbability was prepared by changing the beating degree of silk pulp and the basis weight of silk paper, and photocatalytic silk mask paper was prepared by loading nanometer titanium dioxide (nano-TiO2) on the silk mask paper, then degradation of formaldehyde by silk mask paper loading nano-TiO2 under daylight lamps and ultraviolet lamps were investigated, respectively. Results showed that silk mask paper could adsorb formaldehyde and had higher adsorption efficiency in the initial stage, and the adsorption/desorption equilibrium could be basically achieved in 60 minutes. The adsorption capacity of silk mask paper made from silk pulp with beating degree of 45 oSR was relatively low, and it increased with the increase of beating degree, but there was little change in adsorption when the beating degree of silk pulp exceeded 65 oSR. Under daylight lamps, 26.61 %, 31.42 % and 38.21 % of formaldehyde could be degraded in 180 minutes by silk mask paper loading 1 wt%, 3 wt% and 5 wt% nano-TiO2, respectively. However, under ultraviolet (UV) lamps, 46.23 %, 55.47 % and 66.38 % of formaldehyde could be degraded within the same time, respectively. More formaldehyde could be degraded by photocatalytic silk mask paper under UV lamps than under daylight lamps, and the more the load of nano-TiO2 on the silk mask paper, the higher the degradation rate of formaldehyde within the same time.

In order to obtain paper respirator with dust resistance performance and antibacterial property, silk photo-catalytic respirator paper was made by loading nano-TiO2 photo-catalyst on silk based respirator paper. The pore structure, surface topography and TiO2 distribution, and the filtration performance of silk respirator paper were studied by using a pore size meter (PSM), a field emission scanning electron microscope (FESEM), and a filter tester, respectively. In addition, the antibacterial property of silk respirator paper was also investigated. The results showed that the pore structure and filtration performance of silk respirator paper could be controlled by changing the degree of beating of silk pulp and the basis weight of silk paper. Silk respirator paper of 45 g/m2 made from silk pulp having beating degree of 85 oSR had high filtration efficiency and appropriate filtration resistance. Nano-TiO2 particles were mainly attached to the surface of silk paper, and the loading of nano-TiO2 photo-catalyst resulted in a slight decrease in filtration resistance and filtration efficiency of silk respirator paper. It, however, improved the antibacterial property of silk respirator paper effectively.

“Excellent engineers education training plan” is the major project for China’s higher engineering education reform, and the stage of enterprise learning is the key to the success of it. This paper introduces the ideas and implementing measures for training light chemcal engineering specialty excellent engineers through school-enterprise cooperative education in Zhejiang University Science & Technology. The key of school-enterprise cooperative education is to establish a workable engineering knowledge and engineering ability standard and to make a study plan which throughout four stages and five practice projects, thereby cultivating students’ engineering awareness, engineering quality and engineering practice ability. Establishment of “order” educational mode can arouse the enthusiasm of enterprises to participate in talent training, and assures the success of school-enterprise cooperative education.

With its direction to decentralization, network and intelligence, field bus control system based on CAN has been applied more and more widely to the industrial control field. Aimed at solving the problems in the controlling process of pulp concentration based on analog instruments such as low precision and stability, high power consumption and excessive maintenance cost, an intelligent transmitter with CAN bus communication function is proposed here for pulp consistency control system. It can measure temperature, pressure and differential pressure signals. Methods to design the hardware and software of the transmitter are particular introduced. The hardware comprises industrial PC, single-chip MSC1211Y5, controller SJA1000 CAN and transceiver 82C250 CAN, which can realize the detection, conversion, calculation and communication of pulp concentration parameters. A main routine and a sending/receiving subroutine flow diagram on CAN communication are given in the paper. The system has features of simple structure, good applicability, low energy consumption, high reliability and strong anti-jamming ability and other advantages.