Formation and characterization of the fibres and films from mesophase solutions of cellulose in ammonia/ammonium thiocyanate solvent

Yang, Kap Seung; Theil, Michael H.; Chen, Y.S.; Cuculo, John A.

doi:10.1016/0032-3861(92)90579-l

Cited by 25 publications

(6 citation statements)

References 12 publications

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“…It is noted that a direct and rapid dissolution of cellulose for its fiber preparation has never been reported 27,28. Recently, a new solvent, namely a NaOH/thiourea aqueous solution (1.5:0.65 in M ), has been developed for cellulose in our laboratory 29,30.…”

Section: Introductionmentioning

confidence: 99%

Structure and Properties of Novel Fibers Spun from Cellulose in NaOH/Thiourea Aqueous Solution

Ruan

Zhang

Zhou

et al. 2004

Macromolecular Bioscience

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Cellulose was dissolved rapidly in a NaOH/thiourea aqueous solution (9.5:4.5 in wt.-%) to prepare a transparent cellulose solution, which was employed, for the first time, to spin a new class of regenerated cellulose fibers by wet spinning. The structure and mechanical properties of the resulting cellulose fibers were characterized, and compared with those of commercially available viscose rayon, cuprammonium rayon and Lyocell fibers. The results from wide angle X-ray diffraction and CP/MAS 13C NMR indicated that the novel cellulose fibers have a structure typical for a family II cellulose and possessed relatively high degrees of crystallinity. Scanning electron microscopy (SEM) and optical microscopy images revealed that the cross-section of the fibers is circular, similar to natural silk. The new fibers have higher molecular weights and better mechanical properties than those of viscose rayon. This low-cost technology is simple, different from the polluting viscose process. The dissolution and regeneration of the cellulose in the NaOH/thiourea aqueous solutions were a physical process and a sol-gel transition rather than a chemical reaction, leading to the smoothness and luster of the fibers. This work provides a potential application in the field of functional fiber manufacturing.

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Section: Introductionmentioning

confidence: 99%

Structure and Properties of Novel Fibers Spun from Cellulose in NaOH/Thiourea Aqueous Solution

Ruan

Zhang

Zhou

et al. 2004

Macromolecular Bioscience

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“…52 Meanwhile, fly ash, 53 bamboo leaves, 54,55 rice husks, 24,56,57 and bagasse were extensively studied for their silica content. The initial method for preparing cellulose−silica aerogel is dissolution that is performed using cellulose solvents, such as calcium thiocyanate, 58 ammonium thiocyanate, 59 liquid ammonia/ammonium thiocyanate (NH 3 /NH 4 SCN), 60 and N,N-dimethylacetamide/lithium chloride (DMAc/LiCl). 61 However, these solvents are unaffordable, limited to laboratory scale, and mostly cause serious environmental problems.…”

Section: ■ Introductionmentioning

confidence: 99%

“…The initial method for preparing cellulose–silica aerogel is dissolution that is performed using cellulose solvents, such as calcium thiocyanate, ammonium thiocyanate, liquid ammonia/ammonium thiocyanate (NH 3 /NH 4 SCN), and N , N -dimethylacetamide/lithium chloride (DMAc/LiCl) . However, these solvents are unaffordable, limited to laboratory scale, and mostly cause serious environmental problems. , Therefore, new eco-friendly cellulose solvents were recently developed, such as the NaOH solution. , This solvent system is confined to low-molecular-weight cellulose; hence, some additives such as zinc oxide (ZnO) are added to enhance the solubility of the NaOH solution …”

Section: Introductionmentioning

confidence: 99%

Optimization of the Sound Absorption Coefficient (SAC) from Cellulose–Silica Aerogel Using the Box–Behnken Design

et al. 2022

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Noise pollution, which has become a major environmental issue in urban areas, can be minimized using acoustic insulation derived from cellulose–silica aerogel. The raw materials required in the process include waste newspaper-based cellulose, geothermal silica, and NaOH/ZnO solution. Therefore, this study investigates the effect of cellulose, silica, and ZnO concentrations on optimizing the sound absorption coefficient (SAC) using the Box–Behnken design (BBD). The results showed that the optimum conditions were obtained at 39.8578 wt % cellulose, 16.5428 wt % silica, and 0.5684 wt % ZnO. The impedance test for the cellulose aerogel and cellulose–silica aerogel showed SAC values of 0.59 and 0.70, respectively, and were characterized by XRD, FTIR, BET–BJH, SEM–EDX, and TG. The results of XRD and FTIR data indicate that the product was cellulose–silica aerogel, and the SEM micrographs showed that silica particles were attached to the fiber surface. Furthermore, type IV isotherms were observed in the cellulose–silica aerogel, typical of mesoporous materials. The presence of silica strengthened the aerogel structure, improved its thermal stability, and increased the surface area but decreased its pore size.

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“…In recent years, thiocyanate, thiosulfate, and sulfate are widely found in a number of industrial processes such as textile manufacturing, metal separation, coking, photofinishing, electroplating, and so on. − Before being discharged, these industrial wastewaters must be treated and removed because of their severe harm to human and organisms. − They can also cause serious and persistent pollution to the environment, because they are difficult to hydrolyze and they have the nature of low volatility. − These salts have very important commercial values and are widely used in steel, construction, mining, dyeing, photography, agrochemical, and pharmaceutical industries. − Therefore, separating and recovering of these salts from such industrial effluents become an urgent task for the sake of economic and environmental concerns.…”

Section: Introductionmentioning

confidence: 99%

Solid–Liquid Stable Equilibrium of the Aqueous Quaternary System NH₄SCN–(NH₄)₂S₂O₃–(NH₄)₂SO₄–H₂O at 303.15 K

Zhao

et al. 2014

J. Chem. Eng. Data

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The salts of thiocyanate, thiosulfate, and sulfate exist in a variety of industrial processes such as textile, coking, and electroplating. The effluents from these industries cannot be discharged directly owing to their severe environmental pollution. In addition, there is an opportunity to recover significant commercial value from these effluents. The phase equilibria and phase diagram play a major role in separating and recovering useful resources. In this paper, the phase diagrams of the system NH 4 SCN− (NH 4 ) 2 S 2 O 3 −(NH 4 ) 2 SO 4 −H 2 O and its subsystems at 303.15 K were determined by an isothermal dissolution equilibrium method. In the phase diagram of the quaternary system, there is one invariant point, three univariant curves and three crystallized regions. The invariant point is cosaturated with ammonium thiocyanate, ammonium sulfate, and ammonium thiosulfate (NH 4 SCN + (NH 4 ) 2 SO 4 + (NH 4 ) 2 S 2 O 3 ). The three crystallization regions correspond to ammonium sulfate ((NH 4 ) 2 SO 4 ), ammonium thiocyanate (NH 4 SCN), and ammonium thiosulfate ((NH 4 ) 2 S 2 O 3 ). The first one is the largest area, but the latter two are much smaller ones. The phase diagram can be utilized to separate and recover NH 4 SCN, (NH 4 ) 2 SO 4 , and (NH 4 ) 2 S 2 O 3 selectively and individually from the desulfurization effluents. The result of this paper shows that the environmental pollutant can be converted to the valuable product by a simple, economical, and green process.

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Formation and characterization of the fibres and films from mesophase solutions of cellulose in ammonia/ammonium thiocyanate solvent

Cited by 25 publications

References 12 publications

Structure and Properties of Novel Fibers Spun from Cellulose in NaOH/Thiourea Aqueous Solution

Structure and Properties of Novel Fibers Spun from Cellulose in NaOH/Thiourea Aqueous Solution

Optimization of the Sound Absorption Coefficient (SAC) from Cellulose–Silica Aerogel Using the Box–Behnken Design

Solid–Liquid Stable Equilibrium of the Aqueous Quaternary System NH₄SCN–(NH₄)₂S₂O₃–(NH₄)₂SO₄–H₂O at 303.15 K

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Formation and characterization of the fibres and films from mesophase solutions of cellulose in ammonia/ammonium thiocyanate solvent

Cited by 25 publications

References 12 publications

Structure and Properties of Novel Fibers Spun from Cellulose in NaOH/Thiourea Aqueous Solution

Structure and Properties of Novel Fibers Spun from Cellulose in NaOH/Thiourea Aqueous Solution

Optimization of the Sound Absorption Coefficient (SAC) from Cellulose–Silica Aerogel Using the Box–Behnken Design

Solid–Liquid Stable Equilibrium of the Aqueous Quaternary System NH4SCN–(NH4)2S2O3–(NH4)2SO4–H2O at 303.15 K

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Product

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Solid–Liquid Stable Equilibrium of the Aqueous Quaternary System NH₄SCN–(NH₄)₂S₂O₃–(NH₄)₂SO₄–H₂O at 303.15 K