Properties of hydrated cellulose membranes for hemodialysis after storage and radiation sterilization

1984 ◽  
Vol 18 (6) ◽  
pp. 428-430
Author(s):  
A. R. Rudman ◽  
N. A. Vengerova ◽  
B. S. �l'tsefon ◽  
T. M. Selina ◽  
T. I. Brovkina ◽  
...  
1990 ◽  
Vol 26 (1) ◽  
pp. 124-130
Author(s):  
I. V. Grushetskii ◽  
V. M. Parfeev ◽  
N. A. Vengerova ◽  
A. R. Rudman ◽  
V. B. Eremeev

Author(s):  
K. Cowden ◽  
B. Giammara ◽  
T. Devine ◽  
J. Hanker

Plaster of Paris (calcium sulfate hemihydrate, CaSO4. ½ H2O) has been used as a biomedical implant material since 1892. One of the primary limiting factors of these implants is their mechanical properties. These materials have low compressive and tensile strengths when compared to normal bone. These are important limiting factors where large biomechanical forces exist. Previous work has suggested that sterilization techniques could affect the implant’s strength. A study of plaster of Paris implant mechanical and physical properties to find optimum sterilization techniques therefore, could lead to a significant increase in their application and promise for future use as hard tissue prosthetic materials.USG Medical Grade Calcium Sulfate Hemihydrate Types A, A-1 and B, were sterilized by dry heat and by gamma radiation. Types A and B were additionally sterilized with and without the setting agent potassium sulfate (K2SO4). The plaster mixtures were then moistened with a minimum amount of water and formed into disks (.339 in. diameter x .053 in. deep) in polyethylene molds with a microspatula. After drying, the disks were fractured with a Stokes Hardness Tester. The compressive strengths of the disks were obtained directly from the hardness tester. Values for the maximum tensile strengths σo were then calculated: where (P = applied compression, D = disk diameter, and t = disk thickness). Plaster disks (types A and B) that contained no setting agent showed a significant loss in strength with either dry heat or gamma radiation sterilization. Those that contained potassium sulfate (K2SO4) did not show a significant loss in strength with either sterilization technique. In all comparisons (with and without K2SO4 and with either dry heat or gamma radiation sterilization) the type B plaster had higher compressive and tensile strengths than that of the type A plaster. The type A-1 plaster however, which is specially modified for accelerated setting, was comparable to that of type B with K2SO4 in both compressive and tensile strength (Table 1).


Author(s):  
Aline Krindges ◽  
Vanusca Dalosto Jahno ◽  
Fernando Morisso

Incorporation studies of particles in different substrates with herbal assets growing. The objective of this work was the preparation and characterization of micro/nanoparticles containing cymbopogon nardus essential oil; and the incorporation of them on bacterial cellulose. For the development of the membranes was used the static culture medium and for the preparation of micro/nanoparticles was used the nanoprecipitation methodology. The incorporation of micro/nanoparticles was performed on samples of bacterial cellulose in wet and dry form. For the characterization of micro/nanoparticles were carried out analysis of SEM, zeta potential and particle size. For the verification of the incorporation of particulate matter in cellulose, analyses were conducted of SEM and FTIR. The results showed that it is possible the production and incorporation of micro/nanoparticles containing essential oil in bacterial cellulose membranes in wet form with ethanol.


Membranes ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 204
Author(s):  
Ievgen Pylypchuk ◽  
Roman Selyanchyn ◽  
Tetyana Budnyak ◽  
Yadong Zhao ◽  
Mikael Lindström ◽  
...  

Nanocellulose membranes based on tunicate-derived cellulose nanofibers, starch, and ~5% wood-derived lignin were investigated using three different types of lignin. The addition of lignin into cellulose membranes increased the specific surface area (from 5 to ~50 m2/g), however the fine porous geometry of the nanocellulose with characteristic pores below 10 nm in diameter remained similar for all membranes. The permeation of H2, CO2, N2, and O2 through the membranes was investigated and a characteristic Knudsen diffusion through the membranes was observed at a rate proportional to the inverse of their molecular sizes. Permeability values, however, varied significantly between samples containing different lignins, ranging from several to thousands of barrers (10−10 cm3 (STP) cm cm−2 s−1 cmHg−1cm), and were related to the observed morphology and lignin distribution inside the membranes. Additionally, the addition of ~5% lignin resulted in a significant increase in tensile strength from 3 GPa to ~6–7 GPa, but did not change thermal properties (glass transition or thermal stability). Overall, the combination of plant-derived lignin as a filler or binder in cellulose–starch composites with a sea-animal derived nanocellulose presents an interesting new approach for the fabrication of membranes from abundant bio-derived materials. Future studies should focus on the optimization of these types of membranes for the selective and fast transport of gases needed for a variety of industrial separation processes.


2021 ◽  
Vol 182 ◽  
pp. 109363
Author(s):  
Natalia Rosiak ◽  
Karolina Kilińska ◽  
Robert Skibiński ◽  
Daria Szymanowska ◽  
Andrzej Miklaszewski ◽  
...  

Author(s):  
Ming Yan ◽  
Yilin Wu ◽  
Rongxin Lin ◽  
Faguang Ma ◽  
Zhongyi Jiang

Although many researchers have done lots of studies on improving the selective separation performance of membrane materials, conceptions and applications of membrane-based molecular imprinting separation&recognition with both high permselectivity and...


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