PACMM™ Sheet Material Material Methods develops and manufactures Particle Adsorbent
Composite (PAC) sheet materials for electrochemical electrodes,
and gas or liquid purification. A wide variety of powders can
be custom fabricated into a smooth, strong, thin, flexible sheet.
The sheets can be made up to 95% working material by weight. Particles
in the size range 0.01 to 100 microns are fixed by a nano structured
web of inert, polymer binder. The particles are immobilized, yet
accessible. Porosity can be made in the range of 50 to 90% void
fraction. Sheet thickness can be manufactured in the range 50
to 1000 microns. Sheet properties that can be tailored to applications
include porosity, surface area, strength, and electrical conductivity.
Applications include super capacitors, fuel cells, gas separation,
water filtration, and others. 
Typical Carbon PACMM™ Sheet Specifications
| Property for PACMM™-100
Carbon Sheet |
Unit |
Measured Value |
| Particle Fraction |
Wt % |
95 |
| Density |
g/cm3 |
0.3-0.6 |
| Porosity |
% |
0.7-0.85 |
| BET area |
m2/g |
250-2500 |
| Thickness |
Micron |
50-1000 |
| Area Weight @ 0.01” thick |
g/m2 |
80-160 |
| CCl4 capacity |
% weight |
85-115 |
| Micropore Vol. |
cc/g |
0.2-0.8 |
| Air Permeability @ 0.6
bar |
cm3/(cm2
s)milli Darcy |
2.51 |
| Electrical Resistivity |
Ohm cm |
0.3 |
| Pore size Bubble point |
Micron |
1.5 |
| Pore size standard variation |
% |
3.4 |
| Tensile Strength |
kg/cm2 |
2 |
Zeolite PACMM™ Sheet Recently we succeeded in binding NaX zeolite particles (1-5 micron)
in a sheet form (0.25 mm thick) with only 10 wt % fibrillated
polymer binder. The SEM micrograph shows that the material has
large porosity, which allows good access of gas to zeolite particles.
The adsorption of N2 on zeolite sheets was characterized
by the thermogravimetric method (University of South Carolina).
We did repeated adsorption / desorption cycles of N2
at atmospheric pressure and 45 C on samples activated in situ
(320 C). Under these conditions, the adsorption capacity of the
sheet-formed zeolite (0.235 mmol/g) was comparable with that of
commercial 0.5-0.8 mm NaX zeolite beads (0.215 mmol/g), although
lower than of the raw NaX powder (0.35 mmol/g). However, the rate
of nitrogen adsorption was higher for the sheet formed zeolite
(0.14 mmol/g/min) than for the corresponding zeolite beads (0.10
mmol/g/min), due to better access and lower diffusion path for
gas molecules in the sheet. The free standing NaX powder showed
the highest adsorption rate (0.19 mmol/g/min). This sheet-formed zeolite could be used as a structured adsorbent
bed, in a spiral wound configuration, for N2 –
O2 separation. Improved gas access and faster nitrogen
uptake warrant its suitability for rapid cycle PSA applications.
Preliminary TGA Results
About The Sheets We use a polymer fibril binder to form powdered materials in
a self-supported, flexible sheet form. The binder content in the
finished sheet is typically about 10 % wt, and the fibrillated
form of the binder ensures that the binder does not obstruct access
to the outer surface of powder particles. The material is flexible
and can be spiral-rolled as a parallel passage contactor. We successfully
demonstrated binding carbon nanoparticles (< 0.1 micron) and
activated carbon fine particulates (< 50 micron) in a sheet
form, which showed good mass transfer and adsorption capacity
properties for CO2 adsorption. An H2 purification
project is in progress with a reputed industrial gas company. 
|
