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The sodium lignin sulfonate was grafted into polyacrylamide hydrogel to synthesize polyacrylamide-lignin sulfonate hydrogel. The ammonium molybdate was introduced into the hydrogel network by immersion process to realize vision display. The absorbance, transparency, structure and morphology of sodium lignosulfonate-polyacrylamide hydrogel were measured by UV-Vis, FT-IR and SEM, respectively. The UV-Vis measurement results show that the hydrogel had the advantages of low cost, easy preparation, and excellent performance in quick response within 5 min. In addition, the photochromic and fading processes of hydrogels could be precisely controlled by UV light at different time and temperatures. FT-IR measurements showed that sodium lignosulfonate was successfully incorporated into the polyacrylamide hydrogel. SEM results show that the hydrogel exhibited a dense structure after complete drying, which made the hydrogel less susceptible to fading after photochromism. [ABSTRACT FROM AUTHOR]

In this paper, a green carboxymethyl cellulose sodium (CMC)/gelatin (GL)-glut ar aldehyde (GA) composite aerogel (CL-A) was prepared by using the principle of chemical cross-linking and freeze-drying technology. The effects of different proportions of carboxymethyl cellulose sodium (CMC), gelatin (GL) and different contents of glutaraldehyde (GA) on the microstructure, thermal stability, mechanical strength and thermal insulation and thermal insulation properties of the aerogel were investigated. The experimental results obtained after trying different raw material ratios showed that the compression modulus of the composite aerogel (Cj I弋一Ain)with the ratio of sodium carboxymethyl cellulose (CMC) to gelatin (GL) of 1:2 and the addition of glutar-aldehyde (GA) of 15% is the highest of 3.()3 Mpa, which is 7 times higher than that of pure sodium carboxym-ethyl cellulose (CMC) aerogel, and the mechanical properties have been enhanced effectively. The thermal conductivity of composite aerogel (Ci I<_) is the lowest, which is as low as ().022 W/(m • k) with a better heat preservation effect. At the same time, the composite aerogel (Ci I-) has a denser porous three-dimensional network, which improves the morphology of the composite aerogel to a certain degree. Lastly, the composite aerogel (C J弋-八")has up to 37% residual carbon, which improves the thermal stability to some extent. Tn summary, the compression modulus, microstructure, thermal stability, and thermal insulation properties of the composite aerogel (C-! I<-AI5) after the addition of gelatin (GL) and glutaraldehyde (GA) are improved. [ABSTRACT FROM AUTHOR]

The CNC/PAN composite nanofiber film with high porosity and pure water permeability was prepared by simple electrospinning technology, using concentrated sulfuric acid hydrolyzed skim cotton with high mechanical strength and crystallinity as the reinforcing phase, and combining with polyacrylonitrile (PAN) with good thermal stability and chemical stability. The effect of CNC addition on the properties of the film was investigated through various characterizations, and the results showed that compared with pure PAN, the CNC/PAN composite nanofiber film had good thermal stability, better mechanical properties and hydrophilicity. The changes of thickness, porosity and permeation flux of pure water before and after the use of the film were explored, the oil-water separation performance of the film was analyzed, and its application in the field of water treatment was expanded. [ABSTRACT FROM AUTHOR]

By adding sodium lignosulfonate in the process of polyurethane foam foaming, and using aluminum hypophite (AHP) and expanded graphite (EG) as synergism flame retardants, the sodium lignosulfonate based polyurethane foam (PUF) with flame retardant properties were prepared by “one-step method”. Firstly, the flame retardation properties of the prepared synergism flame retardant PUF materials were characterized by using the limiting oxygen index (LOI) tester. Thermogravimetric analysis (TGA) and CONE calorimetry (CONE) were used to investigate the thermal stability and combustion behavior of flame-retardant PUF materials. Field emission scanning electron microscope (SEM) was used to analyze the microscopic photos of carbon residue after combustion. The analysis results show that when the SLS addition ratio is 4 wt% of the total mass of raw materials, the synergism ratio of AHP and EG is 1∶4, and the addition of the two synergism flame retardants is 30 wt%, the LOI value of biomass-based flame retardant PUF material increases to 31.6%. The addition of coefficent flame retardants improves the thermal stability and carbonization performance of PUF material. Thus, the flame retardant of the material is greatly enhanced. [ABSTRACT FROM AUTHOR]

In this paper, CS-CDS, GL-CDS and SA-CDS were prepared by using chitosan (CS), glucose (GL) and sodium alginate (SA) as the matrix of three biomass materials and melamine. CS-CDS has the best fluorescence performance by comparison. By introducing CS-CDS into the hydrogel based on SA, the specific fluorescence quenching effect of Fe3+ was obtained, and it had good adsorbability and recycle performance. The results show that (CS-CDS)-SA-gel hydrogel can be used as an effective visual detection and adsorption of Fe3+, and has a good application prospect. [ABSTRACT FROM AUTHOR]

Photochromic systems are widely used in visual information storage, ultraviolet and infrared light detection and other fields, but they need to be improved in terms of portability and response sensitivity. In this study, CS-Fe3+ composite hydrogel is synthesized using chitosan (CS), acrylamide (PAAm) as matrix, Fe3+ as cross-linking agent, and ammonium molybdate (Mo7) as photochromic medium. The experimental results show that ammonium molybdate and Fe3+ are introduced into the hydrogel network through coordination bonds. Fe3+ can enhance the photochromic performance of the composite hydrogel in a certain concentration range. The composite hydrogel is sensitive to ultraviolet light, and begins to change color after exposure to ultraviolet light for only 5 minutes. By controlling the ultraviolet light irradiation time and the environmental temperature of the hydrogel, the degree of photochromism and the fading rate of the hydrogel can be controlled. After 75 min at 60 °C-CS-Fe3+ 芸 hydrogel can be completely faded and reused. When illu min ate d, the surface of the hydrogel is covered with masks with different patterns, which can record different information on the hydrogel and endow the hydrogel with optical storage performance. The introduction of photochromic materials into hydrogels not only makes the photochromic materials portable, but also has excellent optical sensitivity and can be better used in ultraviolet light detection and visual information storage. [ABSTRACT FROM AUTHOR]