This study presents a direct-writing structure color patterns on electrospun colloidal fibers by inkjet printing. The colloidal fiber was obtained by electrospinning the aqueous mixture of colloidal particles of poly(...This study presents a direct-writing structure color patterns on electrospun colloidal fibers by inkjet printing. The colloidal fiber was obtained by electrospinning the aqueous mixture of colloidal particles of poly(styrene-methyl methacrylate-acrylic acid) and poly(vinyl alcohol). The pattern was obtained by directly inkjet printing water onto the electrospun colloidal fiber. The pattern formation was attributed to the morphological transition of the colloidal fiber from the fiber aggregation to latex aggregation and the corresponding color change due to the dissolution of poly(vinyl alcohol) by water. Interestingly, a clear and clean image was successfully obtained on the ethanol-treated colloidal fibers film in comparison to a confused and blur image onto the freshly-made film. It is because the treatment process can compact the fiber structure and lower the spreading/wetting behavior of ink on the fiber structure, contributing to the formation of high-quality pattern. Various letters or quick response code were flexibly designed and printed on to colloidal fibers.Furthermore, the pattern can be easily transferred onto flexible substrate, i.e., a flexible printed bracelet. This work will be of great significance for the development of novel wearable functional materials/devices based on electrospun colloidal fibers.展开更多
Carboxy containing colloidal particles were prepared from emulsion copolymerization of styrene-acrylic acid-butyl acrylate.The particle size and the size distribution were determined on mica by atomic force microscopy...Carboxy containing colloidal particles were prepared from emulsion copolymerization of styrene-acrylic acid-butyl acrylate.The particle size and the size distribution were determined on mica by atomic force microscopy after evaporating the water of the diluted emulsion.A sandwich structure covalently attached between the layers and particles has been fabricated from nitro-substituted diazoresin (NDR) and carboxy containing colloidal particles by the self-assembly combining UV irradiation technique.The ionic bonds between the layers and particles convert to covalent bonds under UV irradiation and the stable sandwich structure was achieved successfully.The assembly process,the stability of the film toward DMF etching and the morphology of the films were also reported.展开更多
Properties of Al2O3-coated nano-SiC have been compared with those of as-received SiC. The isoelectric point (IEP) of SiC changed from pH3.4 to pH7.3 after coating with the alumina precursor, which is close to that of ...Properties of Al2O3-coated nano-SiC have been compared with those of as-received SiC. The isoelectric point (IEP) of SiC changed from pH3.4 to pH7.3 after coating with the alumina precursor, which is close to that of alumina. Because both surfaces of coated SiC and AI2O3 possess higher positive charge at pH=4.5-5.0, they are uniformly dispersed in the two-phase aqueous suspensions, Then a mixed powder containing nano-SiC dispersed homogeneously into the Al2O3 matrix was achieved from flocculating the two-phase suspension. Finally, Al2O3/SiC nanocomposites were obtained by coating nano-SiC with Al2O3, in which the majority of SiC particles were located within the AI2O3 grains. The observation by transmission electron microscopy (TEM) and the analysis by the X-ray photoelectron spectroscopy (XPS) showed that cracks propagated towards the intragranular SiC rather than along grain boundaries.展开更多
基金financial support by National Key R&D Program of China (Nos. 2016YFA0200803, 2017YFA0204 504, 2016YFB0402004)the National Natural Science Foundation of China (Nos. 51873221, 51673207, 51373183)
文摘This study presents a direct-writing structure color patterns on electrospun colloidal fibers by inkjet printing. The colloidal fiber was obtained by electrospinning the aqueous mixture of colloidal particles of poly(styrene-methyl methacrylate-acrylic acid) and poly(vinyl alcohol). The pattern was obtained by directly inkjet printing water onto the electrospun colloidal fiber. The pattern formation was attributed to the morphological transition of the colloidal fiber from the fiber aggregation to latex aggregation and the corresponding color change due to the dissolution of poly(vinyl alcohol) by water. Interestingly, a clear and clean image was successfully obtained on the ethanol-treated colloidal fibers film in comparison to a confused and blur image onto the freshly-made film. It is because the treatment process can compact the fiber structure and lower the spreading/wetting behavior of ink on the fiber structure, contributing to the formation of high-quality pattern. Various letters or quick response code were flexibly designed and printed on to colloidal fibers.Furthermore, the pattern can be easily transferred onto flexible substrate, i.e., a flexible printed bracelet. This work will be of great significance for the development of novel wearable functional materials/devices based on electrospun colloidal fibers.
文摘Carboxy containing colloidal particles were prepared from emulsion copolymerization of styrene-acrylic acid-butyl acrylate.The particle size and the size distribution were determined on mica by atomic force microscopy after evaporating the water of the diluted emulsion.A sandwich structure covalently attached between the layers and particles has been fabricated from nitro-substituted diazoresin (NDR) and carboxy containing colloidal particles by the self-assembly combining UV irradiation technique.The ionic bonds between the layers and particles convert to covalent bonds under UV irradiation and the stable sandwich structure was achieved successfully.The assembly process,the stability of the film toward DMF etching and the morphology of the films were also reported.
基金The study was supported by State Key Lab. of New Ceramics and Fine Processing of Tsinghua University Grant No. X.GZ9913.
文摘Properties of Al2O3-coated nano-SiC have been compared with those of as-received SiC. The isoelectric point (IEP) of SiC changed from pH3.4 to pH7.3 after coating with the alumina precursor, which is close to that of alumina. Because both surfaces of coated SiC and AI2O3 possess higher positive charge at pH=4.5-5.0, they are uniformly dispersed in the two-phase aqueous suspensions, Then a mixed powder containing nano-SiC dispersed homogeneously into the Al2O3 matrix was achieved from flocculating the two-phase suspension. Finally, Al2O3/SiC nanocomposites were obtained by coating nano-SiC with Al2O3, in which the majority of SiC particles were located within the AI2O3 grains. The observation by transmission electron microscopy (TEM) and the analysis by the X-ray photoelectron spectroscopy (XPS) showed that cracks propagated towards the intragranular SiC rather than along grain boundaries.
