Welcome to the MCA Services Blog
Welcome to the MCA Services blog and thank you for taking
a look at our first entry.
will be adding new entries on a regular basis and we hope that we will be able
to give lots of information on our services to help everyone better understand
the techniques we have here, how they work and their applications.
would like to start by giving an introduction to what we offer and a little on
the history of MCA Services.
Services: Who we are and what we offer.
Services is a contract analytical laboratory and consultancy specialising in
the physical characterisation of materials, notably porosimetry. The analytical
techniques are applied to a wide and diverse range of materials and industries
but are also quite specialised. We have decades of experience and are always
happy to lend a hand with understanding them, recommending the best options and
What is porosity?
The Oxford English
Dictionary  gives the following definitions:
quality or state of being porous; porous consistency. Also: the degree to which
a substance is porous.
of pores; containing minute interstices through which water, air etc., may
minute interstice between particles of matter especially in soil or rock; a
minute hole or channel in a surface, fabric, natural or artificial membrane,
useful, everyday way of deciding whether a cavity is a pore or not is maybe
this: “if it is deeper that it is wide, then it’s a pore”
It is the extent of
porosity, the size of the pores and their volume, which influences the
properties of a material.
Pore sizes are conveniently
classified as micropores, mesopores and macropores, depending on their size.
The IUPAC classification 
Micropores = <2 nm
Mesopores = 2 – 50 nm
Macropores = >50 nm
sizes relate to the diameter of a cylindrical pore or the width of a slit
make things a little more complicated, there are a few different units that are
commonly used to quote pore sizes;
or Micron (mm)
chart is helpful to understand the different units and we’ve also included millimetres which are perhaps more familiar.
10, 000, 000
1, 000, 000
is Porosimetry ?
Porosimetry is the study of the porous nature of materials
and includes information on the size, volume and area of pores, for example;
- Pore size
- Pore volume
- Total pore volume
- % Porosity
- Pore area
- Surface area
- Bulk density
- Absolute density
Why is porosimetry significant ?
extent of porosity, or even the lack of it, in a material can very often have
profound effects on its performance and functionality. Understanding the porous
nature of a material – whether it is a precursor, an intermediate or a finished
product – can often help in maximising performance, identifying failures,
directing the formulation process or improving manufacturing processes.
How are pores
There is no single
analytical technique for investigating micropores, mesopores and macropores in
one go and so it is necessary to use a combination of techniques.
The most common techniques
are gas adsorption, mercury porosimetry and pycnometry (density measurement).
Of course, the most appropriate technique for a sample and its anticipated
porosity can also be chosen if we know a little about the sample type, its
history (how it was made or used) and the intended application of the results.
have a comprehensive suite of the latest, state-of-the-art instrumentation for
investigating pores from nanometres to microns. Some of the techniques are:
- BET surface area by
- BET surface area by
krypton adsorption (for particularly low surface area samples)
- Gas adsorption for
- Gas adsorption for
investigating mesopores and macropores up to approximately 300 nm
- Mercury porosimetry
for investigating pores of 0.003 – 600 microns
- Mercury pycnometry
for measuring bulk density
- Helium pycnometry
for measuring absolute density
diagram below shows the relationship between pore sizes and the analytical
technique used to characterise them.
What do the results mean ?
analytical techniques together and their reporting options are incredibly
powerful, they are really rather specialised too and can be applied to almost
any material – porous or non-porous.
can be reported in a wide variety of graphical representations, the
distribution of pore characteristics can be calculated in different ways and
many data reduction models can be applied. This can produce a great deal of
data but it is important to select which is the most appropriate for the
material being analysed and also for its intended application.
process can very involved and at MCA Services we have decades of experience
with our analytical techniques and their application to a very wide range of
materials and industries. We are always keen to ensure that our clients gain
the very most from our services and are able to relate the information directly
to the understanding of their materials.
We know about our characterisation techniques and our
clients know about their materials, products and applications. Through
combining this knowledge and expertise the maximum information is gained from
our characterisation services.
our blog we hope to provide information on the techniques themselves: how they
work, some background theory and also some case studies for the analysis of
about MCA Services.
was founded in 1978 as a laboratory-based consultancy and analytical service
specialising in surface area, porosimetry and porosity measurement. On 28th March 2015 the partnership was
converted into a Limited Liability Partnership, designated MCA Services
Cambridge LLP, Regn. No. OC399113. The LLP continues to use the trade name MCA
Services for continuity.
Our fully equipped
laboratories are based about 15 miles from Cambridge, UK and house the
latest equipment for the provision of analytical services to a wide variety of clients, both
in the UK and abroad. The scope of our analytical activities has expanded over the
past thirty years to encompass physical characterisation techniques such as pore size
distribution by gas adsorption, mercury porosimetry, particle size distribution,
density testing and catalyst metal area by chemisorption.
We are proud
of our extensive experience in our analytical techniques and their application.
Of great benefit to our clients is our offer of assistance with interpretation
of results at no extra charge.
The staff at
MCA Services are professionally qualified and senior staff are members of the
Royal Society of Chemistry and hold Chartered Chemist status.
In the late
1980’s, MCA’s expertise in particle technology led to diversification into the
production of biosensor grade materials where high purity, ultra-fine
particulate materials were required.
focus was on a fine grade silver chloride powder
specifically designed for screen printable biosensor reference electrodes and this was
followed by other fine grade powder such as platinum on carbon and ruthenium on
carbon for advanced sensor systems.
technology was successful in gaining four DTi SMART awards for innovative
technology and we now supply our materials to a world market. The use of our
materials has extended beyond bio-sensors to encompass a diverse range of
Oxford English Dictionary online. www.oed.com
Pure and Applied Chemistry 57, 4 (1985) 603