Polymer – Inorganic nanocomposites influence of collodial silica
Promotion date : 23 January 2004
Actually, I could explain it in a simple way: I have been working with nylon and improved its properties. The idea was to work with thermoplastic polymers, such as nylon, to improve its properties by using silica nanoparticles.
So I studied the effect of the addition of the inorganic material in the polymer. Does it improve the properties of the nylon and if so, in what way? And how much to add and how to disperse it? You could roughly compare it with a cup of coffee. You could improve on the taste by adding sugar, but you have to know the exact amount.
What was your thesis about?
Actually, I could explain it in a simple way: I have been working with nylon and improved its properties. The idea was to work with thermoplastic polymers, such as nylon, to improve its properties by using silica nanoparticles. So I studied the effect of the addition of the inorganic material in the polymer. Does it improve the properties of the nylon and if so, in what way? And how much to add and how to disperse it? You could roughly compare it with a cup of coffee. You could improve on the taste by adding sugar, but you have to know the exact amount. Also you have to stir as well, because otherwise you are in for a surprise at the last few sips. The problem with nanoparticles is that they aggregate. So it was a good result to have such a nice dispersion of the nanosilica in the polymer. That has not been easy. That’s why there is a photo of well-dispersed silica into the polymer matrix on the cover of my thesis.
So what was your starting point, did you have any idea what materials to use?
Yes, there is some background literature about silica-reinforced nylon. We started from there. They also applied nanosilica, getting a mechanical improvement by only 5wt% of the inorganic filler. We used even smaller particles than the particles used by others nylon-silica systems, with colloidal silica below 50 nanometres. So far this is the state-of-the-art in the silica dispersion. If I had not managed that I perhaps would have had to change my PhD research.
When did you get the idea that this might work?
In the first six months. I was quite lucky with that. We have a starting point from there and you can then really look into the properties. We focused on the mechanical properties but also on frictional wear. There are other groups working on silica, but all with a different focus point.
Has industry shown an interest?
Yes, they have. Actually two days ago I was asked for a project financed by a company. They were very interested in my tribological results of chapter 4. It was about the possibility of doing the same with another similar system, used in tissue engineering, like bone implants. In my research I ran a test of 10 kms to establish the decrease in wear, but of course with body implants very different tests should be made.
Did they offer you a position to do the research?
Yes, they are writing up a project and asked me to work on it. I still have to check the conditions but it is likely that I will work for them within IMS for some months.
Are you happy with that?
Yes, I am, although I had not planned it because I am not really into bio materials. But it sounds very interesting.
So you are going to stay here. Was it your plan or did you prefer to go back to Mexico?
My original plan is to move to the western part of the Netherlands. I married a Dutchman and he lives in the West. Actually we spoke about the possibility of going to Mexico, but he found an interesting job over there and now we will wait and see what the future brings.
Are there enough job opportunities for you in Mexico?
Mexico, for good or bad, is close to the US. NAFTA ensures free trade between USA, Mexico and Canada. But Mexico also has links with the European Union. So Mexico has potential in industry. Lying in the back of my mind is joining a company with offices in Europe and Mexico.
Coming from a huge place like Mexico City, did you enjoy your stay here in Enschede?
Yes, and in more ways than one. I came to like Enschede and being away from my family was good for my personal development. I learned to look after myself. At first I thought that living alone might be difficult, but I have a wonderful group of colleagues and it turned out to be no problem at all. And also professionally I liked the enormous freedom and lack of hierarchy and encouragement of my professors.
For the summary of the thesis, click here.