LANGMUIR
·
2014
·
IF 4.384
Chen Tian,Shiyu Fu,Youssef Habibi,Lucian A. Lucia
The activation (dehydration) of cellulose nanocrystals (CNCs) toward surface “brush” polymerization is accomplished either by freeze drying or solvent exchange. However, the question of which one of these protocols to choose over the other is generally open-ended. The current study attempts to shed light on this question by installing a standard polymer, polycaprolactone (PCL), onto the surface of both freeze-dried and solvent-exchanged CNCs by ring-opening polymerization (ROP) and examining the differences in polymerization and final product properties. The work is the first to demonstrate that the efficiency of surface polymerization and final product properties are in fact influenced by the protocols. The differences between the two sample PCL-grafted CNCs were investigated by X-ray photoelectron spectroscopy (XPS), elemental analysis, gel permeation chromatography (GPC), and contact-angle measurements. The freeze-dried samples had a significantly reduced PCL surface density. The crystallinity of the solvent-exchanged PCL-grafted CNCs (SECNC-g-PCL), however, was lower than that of either pure CNCs or freeze-dried PCL-grafted CNCs (FDCNC-g-PCL). It was determined that solvent exchange sufficiently modified the CNC surface to provide enhanced reactivity, an effect that was not as apparent for FDCNC-g-PCL. The solvent-exchanged CNCs tended to have more porous, nanotextured surfaces that were tended to be more responsive toward brush polymerization. In addition to the physical dissimilarities in surface morphology and surface accessibility contributing to topochemical differences between the two species, it was also found that the dispersibility, aggregation, and thermal stability were different.
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JOURNAL OF ALLOYS AND COMPOUNDS
·
2013
·
IF 2.39
Chunfa Dong,Xianglin Zhang,Hao Cai
A simple and environmentally friendly method for the synthesis of highly stable and small sized silver nanoparticles with narrow distribution from 3 nm to 17 nm is reported. Silver nitrate, hydroxy propyl methyl cellulose (HPMC) and glucose, were used as silver precursor, capping agents and reducing agents respectively. The formation of silver nanoparticles was observed by change of color from colorless to wine red. The silver nanoparticles were characterized by transmission electron microscopy (TEM), UV–visible spectroscopy (UV–vis), X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FT-IR). The results demonstrated that the obtained metallic nanoparticles were single crystalline silver nanoparticles capped with HPMC. The effects of the reaction time, reaction temperature and the concentration of silver ion and reducing agents on the particle size were investigated. A possible formation mechanism was proposed. The method may be extended to other noble metal for other technological applications such as additional medicinal, industrial applications.
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CELLULOSE
·
2013
·Vol. 20
·期 5
·2427-2437
·
IF 3.476
Yang Dong,Peng Xin-Wen,Zhong Lin-Xin,Cao Xue-Fei,Chen Wei,Sun Run-Cang
Cellulose nanocrystals (CNCs) have drawn tremendous attention because of their extraordinary physical and chemical properties as well as renewability and sustainability. In this work, after a range of pretreatments, such as freeze-drying, ball-milling, mercerization, N -methylmorpholine- N -oxide dissolution and ionic liquid dissolution, various CNCs with different crystalline properties and morphologies were obtained by hydrolysis or oxidation. XRD and AFM were used to determine the influences of pretreatments on the crystalline properties and morphologies of CNCs. New methods, i.e., specific pretreatments followed by sulfuric acid hydrolysis or 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO) oxidation, were developed to obtain sphere-like CNCs. It was found that sphere-like CNCs were more likely to be obtained from cellulose materials possessing high accessibility. Pretreatments produced cellulose with various crystallinities and polymorphs, and therefore changed the yields of CNCs and influenced their morphology. CNCs prepared by TEMPO oxidation generally had smaller size than the corresponding products obtained by sulfuric acid hydrolysis. In addition, for the dissolved/regenerated cellulose, TEMPO oxidation was a better method to yield sphere-like CNCs than sulfuric acid hydrolysis.
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RSC Advances
·
2015
·Vol. 5
·期 63
·50756-50766
·
IF 3.84
Siqi Huan,Long Bai,Guoxiang Liu,Wanli Cheng,Guangping Han
An electrospinning process was successfully utilized to manufacture polystyrene/cellulose nanocrystal (PS/CNC) nanofibrous mats. Morphology, crystallinity, thermal behavior, as well as mechanical and hydrophobic properties of electrospun PS/CNC nanofibrous mats were investigated. Morphological analysis of the obtained nanofibrous mats demonstrated that fine nanofibers with smooth and smaller diameter could be obtained with increased CNC contents. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) results showed that PS and CNCs were physically mixed and CNCs were probably distributed on the surface of the electrospun nanofibers. The structural property e.g. crystallinity of the electrospun nanofibers was examined using wide angle X-ray diffraction (WAXD). It was indicated that crystallinity could be increased as a result of the increased addition of CNCs and aligned nanofiber orientation. Thermal properties of electrospun PS/CNC nanocomposites were enhanced by increasing CNC loading levels. The tensile strength of electrospun PS/CNC nanofibrous mats was elevated 170% by incorporating 7 wt% CNCs in PS matrix, while the ductility was decreased from 60 to 25%. The hydrophobic property could be increased to 138° when 1 wt% CNCs was incorporated.
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ANALYTICAL AND BIOANALYTICAL CHEMISTRY
·
2017
·Vol. 409
·期 13
·3309-3317
·
IF 3.431
Dai Lili,Jin Shanxia,Fan Mengying,Zhou Ping
As one of the most important posttranslational modifications, protein phosphorylation plays an important role in vital movement. However, an efficiency enrichment treatment prior to MS detection is still a crucial step to protein phosphorylation analysis. In this work, a novel hybrid microsphere for efficient phosphopeptide enrichment was prepared by reverse-phase suspension polymerization of cellulose derivative and chitosan. The microspheres bore different kinds of amine groups and the main enrichment mechanism was based on anion exchange. This approach exhibited high selectivity for phosphopeptides from β-casein, α-casein, and non-fat milk. Three phosphopeptides could still be detected when the amount of β-casein was as low as 10 fmol. This study demonstrated a new attractive solid-phase support for phosphopeptide enrichment to meet the increasing need of phosphoproteomics analysis.
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CARBOHYDRATE POLYMERS
·
2015
·
IF 4.074
Guo-min Wu,Di Liu,Gui-feng Liu,Jian Chen,Shu-ping Huo,Zhen-wu Kong
Thermoset nanocomposites were prepared from a waterborne terpene–maleic ester type epoxy resin (WTME) and cellulose nanowhiskers (CNWs). The curing behaviors of WTME/CNWs nanocomposites were measured with rotational rheometer. The results show that the storage modulus ( G ′) of WTME/CNWs nanocomposites increased with the increase of CNWs content. Observations by scanning electron microscopy (SEM) demonstrate that the incorporation of CNWs in WTME matrix caused microphase separation and destroyed the compactness of the matrix. This effect leads to the glass transition temperatures ( T g ) of WTME/CNWs nanocomposites slightly decrease with the increase of CNWs content, which were confirmed by both DSC and DMA tests. The mechanical properties of WTME/CNWs nanocomposites were investigated by tensile testing. The Yong's modulus ( E ) and tensile strength ( σ b ) of the nanocomposites were significantly reinforced by the addition of CNWs. These results indicate that CNWs exhibit excellent reinforcement effect on WTME matrix, due to the formation and increase of interfacial interaction by hydrogen bonds between CNWs nano-filler and the WTME matrix.
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FIBERS AND POLYMERS
·
2017
·Vol. 18
·期 4
·706-712
·
IF 1.113
Meng Guihua,Peng Huili,Wu Jianning,Wang Yixi,Wang Hao,Liu Zhiyong,Guo Xuhong
Superhydrophobic cellulose and chitosan composite aerogel (SCECS) is fabricated through a novel and simple approach for the first time. During the preparation of cellulose and chitosan composite aerogel (CECS), chitosan is selfassemble into number micron-diameter particles on the surface of aerogel, which is similar to the micromorphology of a lotus leaf. Based on the rough surface, CECS is modified by sodium stearate through electrostatic interaction and ion exchange. Water contact angles of 156° are obtained for superhydrophobic aerogel. SCECS can remove various oils from water and with absorption capacities of 10 g/g for oil. Furthermore, the special structure of a non-porous of surface and porous layer of internal is benefit to separate surfactant-stabilized water-in-oil emulsions under gravity.
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NEW JOURNAL OF CHEMISTRY
·
2025
·
IF 2.5
Lin Guo,Shanshan Zhao,Xudong Zheng,Jian Rong,Xi Zhang,Youming Zhu,Guomeng Li,Jinfeng Mei,Zhongyu Li
Neodymium ions are of increasing interest in today's market due to their unique magnetic properties. Therefore, adsorption separation of neodymium is extremely valuable both economically and environmentally. In this work, imprinting cellulose aerogels (IHN-HPMC-NIPAM) with temperature responsiveness were prepared using hydroxypropyl methylcellulose (HPMC) and graphene oxide in combination with ion imprinting technology for selective adsorption of rare earth neodymium ions. The microstructure and physicochemical properties of the aerogels were investigated by means of Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). Moreover, adsorption experiments were also carried out to study the adsorption performance of aerogels. Based on experimental results, IHN-HPMC-NIPAM exhibits a high adsorption capacity and certain adsorption selectivity for Nd3+ ions. Adsorption experiments demonstrated that IHN-HPMC-NIPAM has a selective adsorption effect on neodymium ions in aqueous solutions, with a maximum adsorption capacity of 68.58 mg g−1. Compared with the non-imprinted aerogel, its maximum adsorption capacity for neodymium ions was significantly enhanced, confirming that the introduced ion-imprinting technology played a crucial role in the adsorption process. The cycling experiments indicated that after four adsorption and desorption cycles, the adsorption capacity of IHN-HPMC-NIPAM could still maintain 86% of its initial capacity. The aerogel can be regenerated by temperature, especially due to the introduction of temperature-responsive monomers. The prepared imprinting adsorbent aerogels were highly efficient, green adsorbent materials with great application prospects due to their abundant source of raw materials, simple preparation process, and pollution-free temperature desorption process.
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BIOMACROMOLECULES
·
2025
·
IF 5.4
Xingyu Chen,Fuhao Dong,Sasa Wang,He Liu,Xu Xu
Highly efficient electromagnetic interference (EMI) shielding materials are critical for portable hardware and flexible electronics, where mechanical durability often poses challenges. Here, the excellent wear resistance and flexibility of thermoplastic polyurethane are utilized to provide a “protective layer” for EMI equipment. A carbon nanotube/cellulose/thermoplastic polyurethane (CNT/paper/TPU) composite paper with a three-layer structure was prepared using a coating method. Strong hydrogen bonds between CNTs, cellulose, and TPU ensured robust integration. The composite, with a thickness of 0.54 mm and conductivity of 1040 S/m, achieved exceptional EMI shielding effectiveness of 69.0 dB. It demonstrated durability against water, solvents, bending, and friction while maintaining shielding performance. Furthermore, its excellent mechanical properties and fatigue resistance significantly enhance equipment lifespan. Therefore, it is expected that this work will open a simple strategy for developing materials with excellent durable EMI shielding properties.
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JOURNAL OF POLYMER RESEARCH
·
2024
·Vol. 31
·期 12
·1-11
·
IF 2.6
Wu Peipei,Zhao Yuchang,Zhang Yuwen,Shen Qingyue,Hu Shuaishuai,Chen Shuangjun
Intrinsic moisture permeability of bio-based polymer cellulose diacetate (CDA) is not sufficient for some requirements. Herein, isophorone diisocyanate (IPDI) modified polyethylene glycol (IPEG200) was served as a reactive plasticizer to enhance the water vapor permeability (WVP) of CDA films without plasticizer migration problems. The performances of CDA films were further improved by adding hydrophilic nanometer Al 2 O 3 fillers. Fourier transform infrared spectroscopy (FTIR) was used to the synthesis processes of the prepolymers and their reaction with CDA chains. The crosslinking reaction was indicated by monitoring the gel content. When IPEG200 is 9.66 phr and Al 2 O 3 filler is 5 phr, the WVP is raised to 8.9 × 10 −13 g·cm/cm 2 ·s·Pa, which is much higher than CDA’s. WVP 14.2 × 10 −13 g·cm/cm 2 ·s·Pa of CDA film can be obtained by adding 60 phr PEG600 and 25 phr Al 2 O 3 when using IPEG200 as the compatibilizer. This study provides a simple, feasible, low-cost method for preparing high moisture permeable film by reactive plasticizers.
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Heliyon
·
2024
·
IF 3.4
Xiaran Miao,Wenqiang Hua,Yiwen Li,Fenggang Bian,Tiqiao Xiao
Reducing energy consumption is major challenge in the industrialization of chemical pretreatments for the extraction of cellulose nanofibrils (CNF). In this study, an integrated chemical pretreatment with alkaline/acid-chlorite/TEMPO-oxidant was used for the nano-fibrillation of CNF from pine sawdust (WS). The alkaline and acid-chlorite pretreatments effectively eliminated the non-cellulosic components present in WS, resulting in the delamination of individual cell layers and swelling of the internal structures within the cellulose fiber bundles and cellulose microfibrils that form these layers. The spacing between CNF within the cellulose microfibrils increased from 3.7 nm to 5.5 nm. These loosely packed hierarchical structures facilitated the penetration of the reagent, which led to an increase in the specific surface area during the TEMPO-oxidant reaction and consequently accelerated the reaction rate. The WS was pretreated in a very dilute solution (1 % NaOH and 0.5 % NaClO 2 ) under mild conditions (70 °C for 1 h), which resulted in a significant reduction of the TEMPO reaction time (from 3 h to 30 min) and a lower consumption of the reaction reagent (one fourth of the amount consumed compared to the direct oxidation of WS to achieve the same degree of cellulose nano-fibrillation).
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2025
·
IF 8.5
Zhengqiang Guo,Weigui Xie,Wangyu Liu
The advancement of three-dimensional (3D) printing technology has further promoted the scientific progression of hydrogels within the realm of wearable devices. However, when the viscosity of the hydrogel precursor is large but does not meet the self-supporting requirements, or lacks the participation of monomer with gel phase change characteristics, the 3D printing preparation of hydrogels often becomes difficult. This study delves into a novel 3D printing method aimed at combining direct ink writing (DIW) with vat photopolymerization (VPP) to achieve a broad spectrum of adjustable mechanical properties by introducing cellulose as a medium to modulate both the mechanical and rheological properties of hydrogels. This hybrid method facilitates the efficacious printing preparation of low-viscosity hydrogels, thereby mitigating the stringent viscosity prerequisites inherent in printable hydrogels. Furthermore, the employment of a dual-core coaxial printing technique for the hybrid printing of hydrogel and elastomer serves to ameliorate hydrogel water loss predicaments. As a result, this new 3D printing method broadens the mechanical properties of printable hydrogels and the adjustable range of system viscosity. At the same time, it realizes the integrated printing of encapsulation layer, and improves the service life of hydrogels, and can be applied to the hydrogel-based sensors.
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