Spinning of Endless Bioactive Silicate Glass Fibres for Fibre Reinforcement Applications

Julia Eichhorn,Niko Moritz,Christina Scheffler,Aarón X Herrera Martín,Leena Hupa,Julia Kulkova,Markus Stommel,Rudi Reichenbächer,Martin Groß,Cindy Elschner,Martin Kilo,Ana Prates Soares,Heilwig Fischer

doi:10.3390/app11177927

Abstract

Bioactive glasses have been used for many years in the human body as bone substitute. Since bioactive glasses are not readily available in the form of endless thin fibres with diameters below 20 µm, their use is limited to mainly non-load-bearing applications in the form of particles or granules. In this study, the spinnability of four bioactive silicate glasses was evaluated in terms of crystallisation behaviour, characteristic processing temperatures and viscosity determined by thermal analysis. The glass melts were drawn into fibres and their mechanical strength was measured by single fibre tensile tests before and after the surface treatment with different silanes. The degradation of the bioactive glasses was observed in simulated body fluid and pure water by recording the changes of the pH value and the ion concentration by inductively coupled plasma optical emission spectrometry; further, the glass degradation process was monitored by scanning electron microscopy. Additionally, first in vitro experiments using murine pre-osteoblast cell line MC3T3E1 were carried out in order to evaluate the interaction with the glass fibre surface. The results achieved in this work show up the potential of the manufacturing of endless bioactive glass fibres with appropriate mechanical strength to be applied as reinforcing fibres in new innovative medical implants.

Highlights

The production of continuous fibres from medically approved bioactive glasses would be very attractive for many applications
A broad field of application would arise for resorbable materials. These materials, mostly plastics or metals, are not suitable for load-bearing implants because resorption is inherently accompanied by a loss of mechanical strength
A suggested concept for resorbable polymers reinforced with bioactive glass fibres for medical applications was presented in the publication by Plyusnin et al [19]

Summary

Introduction

When such a supercooled liquid is cooled to lower temperatures, its viscosity increases and the molecules move slower and slower until the structure is “frozen”. This means that the time scales for molecular rearrangements are extremely long compared to the time period of experimental observation, but they can still take place. In contrast to the regular three-dimensional arrangement of the building blocks in crystals (long-range order), in glasses there are only orders in small domains (short-range order). When heated, they do not melt above a certain temperature, but soften gradually [1]

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Discussion

Conclusion