Co-reporter:Qian Wang, Zhao Dong, Xiaoxia Yan, Yanjiao Chang, ... Jiang Zhou
Journal of Bionic Engineering 2017 Volume 14, Issue 3(Volume 14, Issue 3) pp:
Publication Date(Web):1 July 2017
DOI:10.1016/S1672-6529(16)60413-4
Superhydrophobic surfaces are often found in nature, such as plant leaves and insect wings. Inspired by superhydrophobic phenomenon of the rose petals and the lotus leaves, biomimetic hydrophobic surfaces with high or low adhesion were prepared with a facile drop-coating approach in this paper. Poly(vinyl alcohol) (PVA) was used as adhesive and SiO2 nanoparticles were used to fabricate surface micro-structure. Stearic acid or dodecafluoroheptyl-propyl-trimethoxysilane (DFTMS) were used as low surface energy materials to modify the prepared PVA/SiO2 coating surfaces. The effects of size of SiO2 nanoparticles, concentration of SiO2 nanoparticle suspensions and the modifications on the wettability of the surface were investigated. The morphology of the PVA/SiO2 coating surfaces was observed by using scanning electron microscope. Water contact angle of the obtained superhydrophilic surface could reach to 3°. Stearic acid modified PVA/SiO2 coating surfaces showed hydrophobicity with high adhesion. By mixing the SiO2 nanoparticles with sizes of 40 nm and 200 nm and modifying with DFTMS, water contact angle of the obtained coating surface could be up to 155° and slide angle was only 5°. This work provides a facile and useful method to control surface wettability through changing the roughness and chemical composition of a surface.
Co-reporter:YAN DONG;YANJIAO CHANG;QIAN WANG;JIN TONG
Bulletin of Materials Science 2016 Volume 39( Issue 1) pp:35-39
Publication Date(Web):2016 February
DOI:10.1007/s12034-015-1115-5
The present work investigated the influence of surfactants on size and structure of amylose nanoparticles (ANPs) prepared through precipitation. ANPs were fabricated using absolute ethanol containing surfactants (Tween80, Span80 and mixtures of Tween80 and Span80 with ratios of 25/75, 50/50 and 75/25, respectively) as non-solvents. The obtained ANPs were characterized using dynamic light scattering (DLS), scanning electron microscopy and X-ray diffraction. The results showed that surfactant type, concentration and hydrophilic–lipophilic balance (HLB) value had great impact on size of precipitated ANPs. The smallest ANPs with mean size of 155 nm determined by DLS were obtained by using 0.5% (in proportion of the amylose solution volume) of Tween80/Span80 mixture (HLB = 12.33). The precipitated ANPs possessed the V-type crystalline structure no matter whether using the surfactants or not.
Co-reporter:Ziqin Liu, Yan Dong, Haitao Men, Man Jiang, Jin Tong, Jiang Zhou
Carbohydrate Polymers 2012 Volume 89(Issue 2) pp:473-477
Publication Date(Web):20 June 2012
DOI:10.1016/j.carbpol.2012.02.076
Thermoplastic starch (TPS)/poly (vinyl alcohol) (PVA) blend films were post-treated by crosslinking through soaking the films in sodium carbonate aqueous solution and sodium hexametaphosphate aqueous solution sequentially and then heating. The effects of the concentrations of the sodium carbonate aqueous solution and the sodium hexametaphosphate aqueous solution, soaking time, heating temperature and time on the properties of the TPS/PVA blend films were investigated. It was found that the crosslinking modification significantly reduced the moisture sensitivity of the TPS/PVA blend films, i.e., lowered the equilibrium moisture content of the blend films, increased the tensile strength and Young's modulus but decreased the elongation at break of the blend films. The described method could be used for post-treating TPS/PVA based products to optimize their properties.Highlights► Thermoplastic starch (TPS)/PVA blend films were modified by post-crosslinking. ► The post-treatment consists of soaking the films in aqueous solutions and heating. ► The effects of treating conditions on the properties of the films were investigated. ► The described method can be used to optimize properties of TPS/PVA based products.
Co-reporter:Liang Xie;Man Jiang;Xiaogang Dong;Xia Bai;Jin Tong
Journal of Applied Polymer Science 2012 Volume 124( Issue 1) pp:823-831
Publication Date(Web):
DOI:10.1002/app.35083
Abstract
Poly(vinyl alcohol) (PVA)/sodium alginate (SA) blend hydrogels have immense potential for use as functional biomaterials. Understanding of influences of processing parameters and compositions on mechanical and swelling properties of PVA/SA blend hydrogels is very important. In this work, PVA/SA blend hydrogels with different SA contents were prepared by applying freeze–thaw method first to induce physical crosslinking of PVA chains and then followed by Ca2+ crosslinking SA chains to form interpenetrating networks of PVA and SA. The effects of number of freeze–thaw cycles, SA content and Ca2+ concentration on mechanical properties, swelling kinetics, and pH-sensitivity of the blend hydrogels were investigated. The results showed that the blend hydrogels have porous sponge structure. Gel fraction, which is related to crosslink density of the blend hydrogels, increased with the increase of freeze–thaw cycles and strongly depended on SA content. The SA content exerts a significant effect on mechanical properties, swelling kinetics, and pH-sensitivity of the blend hydrogels. The number of freeze–thaw cycles has marked impact on mechanical properties, but no obvious effect on the pH-sensitivity of the PVA/SA blend hydrogels. Concentration of CaCl2 aqueous solution also influences mechanical properties and pH-sensitivity of the blend hydrogel. By altering composition and processing parameters such as freeze–thaw cycles and concentration of CaCl2 aqueous solution, the mechanical properties and pH-sensitivity of PVA/SA blend hydrogels can be tightly controlled. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Co-reporter:Ziqin Liu;Man Jiang;Xia Bai;Xiaogang Dong;Jin Tong
Journal of Applied Polymer Science 2012 Volume 124( Issue 5) pp:3774-3781
Publication Date(Web):
DOI:10.1002/app.35382
Abstract
Thermoplastic starch (TPS)/poly(vinyl alcohol) (PVA) blend films were modified by crosslinking through soaking the films in glutaraldehyde aqueous solution and then heating in an oven. The effects of the concentration of the glutaraldehyde aqueous solution, soaking time, reaction temperature, and time on the crosslinking reaction were investigated. The moisture absorption and mechanical properties of the films were measured to characterize the influence of the crosslinking modification. It was found that the crosslinking modification significantly reduced the moisture sensitivity of the TPS/PVA blend films and increased the tensile strength and Young's modulus but decreased the elongation at break of the TPS/PVA blend films. The described method could be used for posttreating TPS/PVA-based products to optimize their properties. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Co-reporter:Lili Ren, Man Jiang, Jin Tong, Xia Bai, Xiaogang Dong, Jiang Zhou
Carbohydrate Polymers 2010 Volume 82(Issue 3) pp:1010-1013
Publication Date(Web):15 October 2010
DOI:10.1016/j.carbpol.2010.05.041
The influence of surface esterification modification, by using dodecenyl succinic anhydride (DDSA) and octenyl succinic anhydride (OSA), on mechanical properties of corn starch films was investigated. The results showed that the surface modifications significantly increased tensile strength and Young's modulus of starch films; the modification decreased elongation at break of starch films at 75% RH but enhanced it at 95% RH. The effects of NaOH aqueous solution treating time on mechanical properties of starch films were more notable at 75% RH than at 95% RH. The films modified with DDSA were more strong and rigid, while the films modified with OSA were more flexible and ductile.
Co-reporter:Jiang Zhou, Lili Ren, Jin Tong, Liang Xie, Ziqin Liu
Carbohydrate Polymers 2009 Volume 78(Issue 4) pp:888-893
Publication Date(Web):17 November 2009
DOI:10.1016/j.carbpol.2009.07.017
Surface of corn starch films was modified through esterification using dodecenyl succinic anhydride (DDSA) as reactant. The effects of reaction temperature and time, concentration of alkaline aqueous solution for activating starch, concentration of ethanol diluted DDSA, and time of alkaline aqueous solution treatment on the physical properties related to material’s hydrophilic nature, such as moisture absorption and surface water contact angle, were investigated. It was found that the surface esterification modification significantly reduced the moisture sensitivity and surface hydrophilic character of starch film. Due to the hydroxyl groups in the film surface layer were reacted with DDSA, the equilibrium moisture content of the starch film under 95% RH declined 22% and the surface water contact angle increased up to 82% after surface esterification modification.
Co-reporter:Jiang Zhou, Yunhai Ma, Lili Ren, Jin Tong, Ziqin Liu, Liang Xie
Carbohydrate Polymers 2009 Volume 76(Issue 4) pp:632-638
Publication Date(Web):16 May 2009
DOI:10.1016/j.carbpol.2008.11.028
Surface crosslinked thermoplastic starch (TPS)/PVA blend films were prepared by applying ultra violet (UV) irradiation. Sodium benzoate was used as photosensitizer and induced onto film surface layer by soaking the TPS/PVA films in the photosensitizer aqueous solution. The effects of concentration of photosensitizer aqueous solution, soaking time and UV irradiation dose on the surface photocrosslinking reaction were investigated. Physical properties, such as water contact angle, moisture absorption, swelling degree and solubility in water as well as mechanical properties of the films were measured to characterize the influence of the surface photocrosslinking modification. The obtained results showed that the surface modification considerably reduced the surface hydrophilic character of the TPS/PVA films, enhanced the film’s water resistance and also increased tensile strength and Young’s modulus but decreased elongation at break of the films.
Co-reporter:Jiang Zhou;Lili Ren;Jin Tong ;Yunhai Ma
Journal of Applied Polymer Science 2009 Volume 114( Issue 2) pp:940-947
Publication Date(Web):
DOI:10.1002/app.30709
Abstract
Surface of corn starch films was modified through esterification using octenyl succinic anhydride as reactant. Physical properties of the films, moisture absorption, and water contact angle were measured to characterize the effect of the surface esterification modification. The influences of the concentration of alkaline aqueous solution for activating starch, reaction temperature, and time were investigated. It was found that the pretreatments with 1.0% or 2.0% NaOH aqueous solution and reacting at 35°C for 6 h gave rise to films possessing higher water contact angle, lower equilibrium moisture content, and moisture absorption rate at 95% relative humidity (RH). After the surface esterification modification, the equilibrium moisture content of the starch film decreased up to 29% at 95% RH and the surface water contact angle of the film increased up to 83%. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Co-reporter:Jiang Zhou;Yunhai Ma;Jian Zhang ;Jin Tong
Journal of Applied Polymer Science 2009 Volume 112( Issue 1) pp:99-106
Publication Date(Web):
DOI:10.1002/app.29399
Abstract
The surface of glycerol plasticized thermoplastic starch (TPS) sheets was modified by photocrosslinking under ultra violet (UV) irradiation. Sodium benzoate was selected as photosensitizer and induced onto sheet surface layer by soaking the sample sheets in photosensitizer aqueous solution. The effects of concentration of the photosensitizer aqueous solution, soaking time and moisture content in sheets before UV irradiation on the photocrosslinking were investigated. Water contact angle, moisture absorption, and mechanical properties were measured to characterize the influence of the surface photocrosslinking modification on the properties of TPS sheets. The obtained results showed that the surface photocrosslinking treatments markedly reduced the water sensitivity of TPS sheets and enhanced their tensile strength and Young's modulus but decreased the elongation at break. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Co-reporter:Yanjiao Chang, Xiaoxia Yan, Qian Wang, Lili Ren, Jin Tong, Jiang Zhou
Food Chemistry (15 July 2017) Volume 227() pp:
Publication Date(Web):15 July 2017
DOI:10.1016/j.foodchem.2017.01.111
•Starch aqueous solutions were treated by ultrasound for different periods of time.•The ultrasonic treatment led to decrease in viscosity and starch chain scission.•Starch nanoparticles (SNPs) were prepared through nanoprecipitation.•The ultrasonic treatment gave the SNPs smaller size and narrower size distribution.•Ultrasonic treatment can be used to overcome the shortcomings of nanoprecipitation.The purpose of this work was to develop an approach to produce size controlled starch nanoparticles (SNPs), via precipitation with high efficiency and low cost. High concentration starch aqueous pastes (up to 5 wt.%) were treated by ultrasound. Viscosity measurements and size exclusion chromatography characterization revealed that, after 30 min ultrasonic treatment, viscosity of the starch pastes decreased two orders of magnitude and the weight average molecular weight of the starch decreased from 8.4 × 107 to 2.7 × 106 g/mol. Dynamic light scattering measurements and scanning electron microscopy observations showed that the SNPs prepared from the starch pastes with ultrasonic treatments were smaller (∼75 nm) and more uniform. Moreover, SNPs could be obtained using less non-solvents. X-ray diffraction results indicated that effect of the ultrasonic treatment on crystalline structure of the SNPs was negligible. Ultrasound can be utilized to prepare smaller SNPs through nanoprecipitation with higher efficiency and lower cost.
![3-[(e)-dodec-1-enyl]oxolane-2,5-dione](http://img.cochemist.com/ccimg/25400/25377-73-5.png)
![3-[(e)-dodec-1-enyl]oxolane-2,5-dione](http://img.cochemist.com/ccimg/25400/25377-73-5_b.png)