AIP Advances
·
2021
·Vol. 11
·期 11
·
IF 1.548
Huang Lijie,Wei Zhehao,Wang Yanan,Han Xiaoxue,Chen Haobin,Huang Chongxing,Wei Yingnan
In this paper, the effect of D 0 temperature, Kappa factor and the final pH value on bleaching sulfate bleached pine wood pulp was studied. The results showed that the bleaching efficiency was better when the pH value was 4, and the amount of absorbable organic halogen (AOX) in the bleaching wastewater was decreased. The Kappa factor is linear with the whiteness in the range of 0–0.15. With the increase of the Kappa factor, the amount of AOX in bleaching wastewater of D 0 and Ep gradually increases. High temperature bleaching can reduce AOX production, but some fibers are hydrolyzed, leading to a decrease in pulp viscosity. The effects of chlorine dioxide solution adding sodium dihydrogen phosphate (NaH 2 PO 4 ) and dimethylsulfoxide (DMSO) on pulp bleaching were investigated. The results showed that both solutions could reduce the amount of AOX in bleaching wastewater. Among them, the addition of NaH 2 PO 4 in chlorine dioxide increased pulp whiteness, while the addition of DMSO was the opposite. Scanning electron microscope showed that a small amount of hollow cracks and more voids appeared on the surface of pulp fibers after the addition of NaH 2 PO 4 . Pulp fibers bleached by the chlorine dioxide adding DMSO have more folds and less voids on the surface. The surface wrinkles of pulp fibers increased with the addition of DMSO and the voids were less. FT-IR showed that the number of chromophore groups in the pulp bleached by chlorine dioxide adding NaH 2 PO 4 were decreased. However, the lignin characteristic absorption peak in the pulp bleached by chlorine dioxide adding DMSO increased at the intensity of 1062 and 1160 cm −1 , which indicated that there were more residual chromophore groups.
研究领域:
制浆造纸工程
·
环境科学
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产品关联
DOI
高影响因子
FIBERS AND POLYMERS
·
2018
·Vol. 19
·期 9
·1898-1907
·
IF 1.353
Yu Deyou,Wu Minghua,Lin Junxiong,Zhu Jintao
Conventional cotton bleaching is highly energy-intensive, water-dependent, and textile-damaging. The technologies currently used to achieve low-temperature bleaching always include a conflict between effectiveness and cost. This study represents an economically efficient process for cotton bleaching with H 2 O 2 at low temperature. A novel system that couples Cu 2+ with HCO
− 3
, has been developed to activate cotton bleaching. Factors that influence the bleaching performance were investigated, including the bleaching temperature and initial concentrations of the components (H 2 O 2 , NaHCO 3 and Cu 2+ ). The experimental results indicated that the Cu 2+ -HCO
− 3
/H 2 O 2 system had a lower operating cost and higher bleaching efficiency than conventional and TAED-activated systems. Additionally, the bleaching bath exhibited excellent reusability, further strengthening its feasibility for industrial applications. The results of HO• scavenging and Cu 2+ monitoring experiments implied that the bleaching active species might be the Cu(III) species rather than HO•. This novel system provides a simple, effective, and cost-efficient method for practical bleaching.
研究领域:
纺织科学
·
化学工程
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产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2025
·
IF 8.5
Xiao Zhao,Baojie Liu,Hao Xu,Chengrong Qin,Shuangquan Yao,Chen Liang,Shuangfei Wang
Elemental Chlorine-Free (ECF) bleaching is a globally prevalent pulping technology that primarily utilizes chlorine dioxide (ClO 2 ) as a bleaching agent. However, the chlorination side reactions during ECF bleaching lead to the formation of chlorinated adsorbable organic halides (AOX), which are difficult to degrade and pose a potential threat to the ecological environment. This study presents a novel high-concentration ClO 2 pulping bleaching technology at room temperature, which effectively suppresses the chlorination side reactions through the strong oxidizing properties of high-concentration ClO 2 , thereby achieving both bleaching and a reduction in AOX generation. The results indicate that high concentrations of ClO 2 efficiently removed residual lignin from the pulp, promoted the cleavage of lignin ether bonds, and had no adverse impact on the strength or crystalline structure of the cellulose. The amount of AOX was effectively controlled to 0.41 kg/t pulp. Kinetic analysis demonstrated that the degradation of lignin in this bleaching system follows first-order reaction kinetics, with an activation energy of 1310.78 J/mol. Approximately 95 % recovery of the ClO 2 solution was achieved through a four-step reabsorption method. This technology advances the development of pulping and bleaching techniques and provides theoretical guidance for the innovation of cleaner pulping and papermaking technologies.
研究领域:
制浆与造纸工程
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
NORDIC PULP & PAPER RESEARCH JOURNAL
·
2019
·Vol. 35
·期 1
·18-24
·
IF 0.929
Hailong Li,Chao Du,Shujuan Ge,Mengru Liu
This study aimed to investigate the oxalate formation mechanism during chlorine dioxide (
ClO
2
) bleaching of bamboo kraft pulp, and thus explore favourable
ClO
2
bleaching conditions to better control oxalate formation. The amount of oxalate formed varied linearly with
ClO
2
dosage within the whole research range, while it rose exponentially within the first 90 mins of pulp bleaching. Then the actual bleaching process was simulated by reacting
ClO
2
with three representative lignin model compounds and comparatively studied. The rule of oxalate formation in the simulated reaction system was identical to that in pulp bleaching by
ClO
2
, except for oxalate production by veratraldehyde with prolonged reaction time. Under identical conditions, vanillin formed the highest amount of oxalate, while veratraldehyde formed the least. Furthermore, the amount of oxalate formed increased by 19.59 mg/kg when the kappa number of the delignified pulp was reduced by one unit. Considering the satisfactory pulp brightness and decreased oxalate formation, the recommended conditions for
ClO
2
bleaching of bamboo kraft pulp were a
ClO
2
dosage of 4 %, 60 °C and 70 mins.
研究领域:
制浆造纸工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Cleaner Production
·
2022
·
IF 11.072
Kai Li,Zhu-yu Li,Cheng-Bo Zhang,Jia-qi Zhao,Li Zhao,Ji Liu,Shan-wei Ma,Qiang Lu
This study was focused on the value-increment of spent bleaching clay (SBC) to produce aromatic hydrocarbons and regenerated bleaching clay (RBC) via ex-situ catalytic pyrolysis with HZSM-5. The catalytic pyrolysis experiments were conducted to clarify the regulatory functions of pyrolytic temperature and SBC-to-HZSM-5 ratio (S/H) on the product distribution and aromatics generation. The adsorbed oil in SBC could be decomposed almost completely at 450 °C. The optimum aromatics yield of 3.49 wt% was achieved at catalytic temperature of 600 °C and S/H of 15. The solid product obtained under this condition underwent calcination at 500 °C and acid treatment successively to prepare RBC. The treatment did not affect the montmorillonite structure of clay. The RBC possessed good porous structures with newly generated micropores . The specific surface area and pore volume of RBC reached 163.32 m 2 /g and 0.29 cm 3 /g, higher than those of 146.17 m 2 /g and 0.25 cm 3 /g of fresh activated bleaching clay (ABC), indicating the better adsorption performance of RBC.
研究领域:
化学工程
·
环境科学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
·
2022
·Vol. 23
·期 21
·13310
·
IF 6.208
Yi Liu,Baojuan Deng,Jiarui Liang,Jiao Li,Baojie Liu,Fei Wang,Chengrong Qin,Shuangquan Yao
Chlorine dioxide is widely used for pulp bleaching because of its high delignification selectivity. However, efficient and clean chlorine dioxide bleaching is limited by the complexity of the lignin structure. Herein, the oxidation reactions of phenolic (vanillyl alcohol) and non-phenolic (veratryl alcohol) lignin model species were modulated using chlorine dioxide. The effects of chlorine dioxide concentration, reaction temperature, and reaction time on the consumption rate of the model species were also investigated. The optimal consumption rate for the phenolic species was obtained at a chlorine dioxide concentration of 30 mmol·L−1, a reaction temperature of 40 °C, and a reaction time of 10 min, resulting in the consumption of 96.3% of vanillyl alcohol. Its consumption remained essentially unchanged compared with that of traditional chlorine dioxide oxidation. However, the consumption rate of veratryl alcohol was significantly reduced from 78.0% to 17.3%. Additionally, the production of chlorobenzene via the chlorine dioxide oxidation of veratryl alcohol was inhibited. The structural changes in lignin before and after different treatments were analyzed. The overall structure of lignin remained stable during the optimization of the chlorine dioxide oxidation treatment. The signal intensities of several phenolic units were reduced. The effects of the selective oxidation of lignin by chlorine dioxide on the pulp properties were analyzed. Pulp viscosity significantly increased owing to the preferential oxidation of phenolic lignin by chlorine dioxide. The pollution load of bleached effluent was considerably reduced at similar pulp brightness levels. This study provides a new approach to chlorine dioxide bleaching. An efficient and clean bleaching process of the pulp was developed.Keywords:lignin;chlorine dioxide;oxidation;bleaching;pulp
研究领域:
化学工程
·
林产化学
·
环境科学
✓ 已验证
DOI
PubMed
高影响因子
COLORATION TECHNOLOGY
·
2015
·Vol. 131
·期 6
·439-443
·
IF 1.262
Zongqian Wang,Weiguo Chen,Xuewei Zhou,Chaonan Liu,Keith Millington
Bleached silk is rapidly yellowed by exposure to the ultraviolet radiation present in sunlight. The conventional application of a water-soluble hydroxyphenyl benzotriazole ultraviolet absorber (such as UVFast W) to bleached silk reduces its rate of photoyellowing but has a negative impact on the whiteness of the bleached silk, largely cancelling out the improvements in whiteness achieved during bleaching. Therefore, a series of bleaching processes and aftertreatments using UVFast W on silk were investigated, with the measurement of reflection spectrum, whiteness, yellowness, and strength before and after exposure to ultraviolet radiation. The results show that whiteness of silk treated by oxidation–reduction double bleaching can be increased, and the whiteness of double-bleached silk with 4% UVFast W aftertreatment was even slightly higher than that of the hydrogen-peroxide-bleached silk. After ultraviolet irradiation, double-bleached silk samples with 4% UVFast W treatment resulted in both the highest whiteness and optimum photostability by comparison with unbleached standard silk and hydrogen-peroxide-bleached silk samples with and without 4% UVFast W treatment, and its strength difference was superior to the samples, except for standard silk with 4% UVFast W treatment after exposure to UV radiation for 18 h.
研究领域:
材料科学
·
纺织工程
·
光化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Cleaner Production
·
2023
·
IF 11.1
Jiajun Pan,Zhaopeng Xia,Haibao Zhang,Liwei Wu,Yang Lu,Yong Liu,Yujie Cao
Animal fibres are coloured using dyes to satisfy the individual needs; thus, dark animal fibres must be bleached. Compared with frequently used Fe 2+ -catalysed H 2 O 2 (Fe 2+ /H 2 O 2 ) bleaching, persulphate (PDS)/H 2 O 2 bleaching is advantageous owing to its high efficiency, low damage of fibre and environmental friendliness. Herein, different free radical species were precisely controlled by changing the pH of the PDS/H 2 O 2 solution and regulating the existence of NH 4 + . When NH 4 + was absent, sulphate radicals (·SO 4 − ) and hydroxyl radicals (·HO) could be produced at pH = 8–9 and superoxide anions (·O 2 − ) could be produced at pH = 10. In the presence of NH 4 + , ·SO 4 − and ·HO could be produced at pH = 8, and ·O 2 − was dominant in the solution when pH = 9–10. Black yak wool was used as the research object to demonstrate that the bleaching ability of the generated ·O 2 − was stronger than those of the generated ·SO 4 − and ·HO. Compared with that of the commercial product (prepared using Fe 2+ /H 2 O 2 bleaching), the bleaching time of the decolourised yak wool was reduced by 83.33% (from 24 to 4 h) without the catalysis by heavy metal ions . Meanwhile, the whiteness of the decolourised yak wool (72.31%) was close to that of the commercial product (78.79%). Furthermore, the damage to the cuticle layer and cortex of yak wool was low after bleaching. The breaking strength of the decolourised yak wool was 1.79 cN·dtex −1 , which only decreased by 17.13% compared with that of raw yak wool. These results hold great potential in developing environmental-friendly bleaching methods for dark animal fibres with high efficiency and low damage.
研究领域:
纺织科学
·
环境科学
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产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2018
·
IF 8.097
Zhiquan Li,Xiucheng Zou,Guigang Zhu,Xiaoya Liu,Ren Liu
Developing efficient unimolecular visible light-emitting diode (LED) light photoinitiators (PIs) with photobleaching capability, which are essential for various biomedical applications and photopolymerization of thick materials, remains a great challenge. Herein, we demonstrate the synthesis of a series of novel PIs, containing coumarin moieties as chromophores and oxime ester groups as initiation functionalities and explore their structure–activity relationship. The investigated oxime esters can effectively induce acrylates and thiol-based click photopolymerization under 450 nm visible LED light irradiation. The initiator O-3 exhibited excellent photobleaching capability and enabled photopolymerization of thick materials (∼4.8 mm). The efficient unimolecular photobleachable initiators show great potential in dental materials and 3D printings.
研究领域:
材料科学
·
化学
·
生物医学工程
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产品关联
DOI
PubMed
高影响因子
Materials
·
2022
·Vol. 15
·期 17
·5849
·
IF 3.748
Qing Li,Run Lu,Yan Liang,Kang Gao,Huiyu Jiang
The traditional pre-treatment of cotton fabric hardly meets the requirement of low carbon emissions due to its large energy consumption and wastewater discharge. In this study, a low-temperature and near-neutral strategy was designed by establishing a tetraacetylethylenediamine (TAED)-activated sodium percarbonate (SPC) system. First, the effects of SPC concentration, temperature and duration on the whiteness index (WI) and capillary effect of cotton fabrics were investigated. Particularly, excess SPC’s ability to create an additional bleaching effect was studied. The optimized activated pre-treatment was compared with the traditional pre-treatment in terms of the bleaching effect and energy consumption. Further, the degradation of morin, which is one of the natural pigments in cotton, was carried out in a homogeneous TAED/SPC system to reveal the bleaching mechanism. Lastly, the application performance of the treated cotton was evaluated by characterizing the dyeability, mechanical properties, morphology, etc. The research results showed that temperature had a significant influence on both theWIand capillary effect, followed by the SPC concentration and duration. TheWIwas positively correlated with the SPC concentration, but excess SPC could not produce an obvious additional effect. TheWIof the fabric increased by 67.6% after the optimized activated bleaching using 10 mmol/L SPC and 15 mmol/L TAED at 70 °C for 30 min. Compared with the traditional process performed at 95 °C for 45 min, the activated process produced approximately 39.3% energy savings. Research on the bleaching mechanism indicated that the reactive species that participated in degrading the morin were the hydroxyl radical and superoxide radical, and the contribution degree of the former was larger than that of the latter. Two degradation components with molecular weights of 180 and 154 were detected using mass spectroscopy. Based on this, the bleaching mechanism of the TAED/SPC system was proposed. Moreover, the fabric after the activated pre-treatment had a suitable dyeability and strength, a lower wax residual and a smoother and cleaner fiber surface. The encouraging results showed that TAED/SPC is a promising bleaching system that is conducive to the sustainable advance of the textile industry.Keywords:pre-treatment;cotton;sodium percarbonate;bleaching mechanism;energy conservation
研究领域:
纺织工程
·
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FOOD RESEARCH INTERNATIONAL
·
2022
·
IF 7.425
Yufeng Zou,Jianbo Zhang,Yumin Niu,Dengyong Liu
The key constituent(s) of sugar-smoking brown pigments were identified, the chemical and biological properties were subsequently investigated, and the possibility of obtaining it from nature was explored. A pigment was isolated, which was identified as condensation product of 5-hydroxymethyl-2-furfuraldehyde (5-HMF) with glucose: 5-(α-D-glucopyranosyl-(1–6)-α-D-glucopyranosyloxymenthyl)-2-furancarboxaldehyde (5-GGMF). The molecular weight was 450.00. The interaction between pigment with protein on chicken skin was mainly via hydrogen and carbon-hydrogen bonds. It was obtained by caramelization instead of Maillard reaction. Discoloration of sugar-smoking pigments were mainly due to cleavage of chromophores caused by the oxidation reaction followed by photobleaching mechanism. Both radical scavenging and antiproliferative capacity of sugar-smoking pigment were in a dose-dependent manner. However, the IC 50 values for HepG2 and PANC-1 cells differed by more than ten times. Since 5-GGMF is also present in plant resources (like Rehmanniae Radix ), it can be obtained as natural additive to produce clean label sugar-smoked meat products.
研究领域:
食品科学
·
生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SOLAR ENERGY
·
2022
·
IF 7.188
Kai Sheng,Mahmoud A. Khalifa,Zitao Wang,Jianming Zheng,Chunye Xu
Developing a low-cost and efficient Photovoltachromic Device (PVCD) can address the requirements of energy-harvesting smart windows . In this work, low-cost poly(3,4-(2,2-dimethylpropylenedioxy)thiophene) (PProDOT-Me 2 ) is presented for replacing expensive Pt and achieving a WO 3 -based PVCD with rapid bleaching speed. The device consists of the proposed WO 3 /PProDOT-Me 2 electrode, an electrolyte containing I − /I 3 − redox couple , and dye-sensitized TiO 2 photoanode. The PVCD changes state between colored and bleached by simply altering the open and short circuit of the device. The PVCD achieves high optical contrast of 45.1% at 680 nm with a fast bleaching time of 15.5 s, coloring time of 3.6 s, and cycling stability over 200 cycles. These unique characteristics result from the PProDOT-Me 2 could help accelerate the electrochromic process of WO 3 and fast transferring charges to the electrolyte that enhances photovoltaic performance . The accelerating mechanism is analyzed and the related experimental evaluations are executed. This study reveals promising prospects of the proposed WO 3 -PProDOT-Me 2 electrode for low-cost PVCD.
研究领域:
材料科学
·
能源技术
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）