b-cyclodextrin Molecules and Their Use in Breathable Barriers

by
Michelle Roberts
May 3, 1999
TE589A
Theory of Inventive Problem Solving
North Carolina State University (N.C.S.U.)
Under the direction of:
Dr. Michael S. Slocum
Adjunct Assistant Professor
N.C.S.U.
Dr. Timothy G. Clapp
Professor
N.C.S.U.

Introduction

Oftentimes, the creative process is tackled by inventors without much direction. In 1946, a Russian inventor named Genrich Altshuller decided that a concrete approach to problem- solving was needed. He realized that the creative process did not arise through chance, but rather, was governed by certain laws. He outlined a series of steps that the inventor can go through which will ensure a solution to the problem at hand which is the most innovative solution possible.

The bulk of Altshullerís theory is based on the careful inspection of thousands of patents that had been filed in Russia. Altshuller noted that same solutions to similar problems kept arising in the patent literature, even across different fields. He realized that the inventor, armed with these solutions, could make more progress and solve problems more creatively than without this information. He went about cataloging these patents into categories and came up with 40 basic solutions, which were used to solve all the problems he encountered in the patent literature.

 

Objective

The objective of this research is to apply the TRIZ methodology to a complex problem encountered in the field of chemical protection garments worn by soldiers potentially exposed to chemical or biological hazards. The methods used in this research will be outline here, and will be explained in greater detail later in this research:

TRIZ Methods Used:

Innovative Solution Questionnaire (ISQ)

Ideality

Separation Principles

Contradiction Matrix Theory

ARIZ 95C

ISQ- Innovative Situation Questionnaire

The ISQ was developed at the Kishinev School of TRIZ in Moldova. It gives the innovative problem solver the tools to properly identify the problem at hand. By breaking the problem down and gathering all the necessary information about it, the problem solver is in the best possible position to solve the problem innovatively.

Information about the system to be improved and its environment

1.1 System name

Technical system: Breathable barrier film that will protect the soldier from biological and/or chemical hazards but allow the non-hazardous transmission of air and perspiration through the garment.

1.2 Systemís primary useful function

The systemís primary useful function is that the b- cyclodextrin molecules chemically bond to the molecules of the substance y, so that they do not pass to the other side.

The primary useful function of the barrier substance is that it chemically bonds to the b- cyclodextrin molecules, thus providing a means for the b- cyclodextrin molecules to cover the area that needs to be free of substance y.

1.3 Current or desired system structure

Barrier substance is used to prevent dangerous or unwanted substances from passing through it. Barrier substance can exist as part of a clothing ensemble, which is worn on the body. There is no acceptable amount of dangerous substance y which can be allowed to pass through. Dangerous substance y can be of the liquid form or the gaseous for. Substance y can be a mixture of several different substances. The barrier film exists as a substrate for the cage-like molecules that are responsible for the entrapment of the molecules of y. The film that is used as a substrate for the cage-like molecules is continuous in nature, with no holes or pores. This is an ideal situation from the standpoint of attachment of molecules to the film, because it allows for the maximum number of molecules to be chemically attached to the surface film. The barrier film, however, needs to allow moisture vapor (MV) to be transported through the film so that the individual wearing it will not succumb to heat stress. b- cyclodextrin is added to the barrier film to enhance barrier qualities.

Diagram of Current System

The system is also comprised of two subsystems: the y moleculeís interaction with the cage-like molecules, and the cage- like molecules interaction with three water molecules. The dangerous molecules of y are chemically bound to the outside and inside of the cyclodextrin. The water molecules are also attached to the inside of the cage-like molecules.

Subsystem #1

Subsystem #2

 

1.4 Functioning of the System

When the system executes itís primary useful function, the dangerous molecules come into contact with the barrier substrate with the b-CD molecules chemically bound to the substrate. The first subsystem is the interaction between the dangerous chemical molecules, the barrier substrate, and the b-CD molecules. When y touches the barrier, nothing happens. There is no chemical reaction between the particle and the barrier. If there is any sort of electrical charge on either the substrate or the molecules, there could be some small attractive or repulsive force. However, when the particles come in contact with the cage-like molecules, the molecule becomes bound to the cage-like molecules. In this manner, the dangerous particle cannot pass through the film.

The b- CD will complex with any molecule or particle which has a polarity less than water. The interior of the cage-like molecule is hydrophobic and the outside is hydrophilic.

1.5 System Environment

The film with the cage-like molecules on it will be in contact with moisture in the air, as well as any gases that are in the ambient atmosphere. It will also be in contact with any harmful molecules in the environment.

2.0 Available Resources

This step of the ISQ is to list every possible available resource in the system or accessible to the system. In this way, a solution can be found using resources that are already present, thus increasing the ideality of the system, leading to a truly innovative solution.

Resources (Intended to be a complete list of available resources at the sub-system, system, and super-system level)

Size of CD moleuces

Temperature of system

Orientation of film

Size of y molecules

Temperature difference across film

Thermal capacity of CD

Size of water molecules

Temperature of water vapor

Thermal capacity of film

Amount of CD molecules

Elecctrical capacity of film

Thermal capacity of y

Amount of y molecules

Electrical capacity of CD

Frictional property of film

Amount of water molecules

PH of the CD

Coefficient of friction

Air molecules touching system

Ph of y

Melting point of film

Nitrogen

Strength of film

Melting point of CD

Size of nitrogen

Strength of CD

Decomposition point of film

Amount of nitrogen

Cellulose molecules attaching to CD

Decomposition point of CD

Oxygen

-OH groups in CD

Decomposition point of y

Amount of nitrogen

Specific gravity of y

Heat of fusion of film

Thickness of film

Electric charge of y

Resistivity of film

Pores in film

Concentration of y

Resistivity of CD

Density of film

C, H, O molecules in CD

Resistivity of y

Size of molecules in film

Solubility of CD

Resistivity of air

Electric charge on CD

Elacticity of film

Conductivity of film

Weight of the CD

Density of CD on film

Conductivity of CD

Charge of the film

Location of CD on film

Conductivity of y

Density of y

Residual stress in film

Size, shape of film

3.0 Information about the problem situation

3.1 Desired improvement to the system or a drawback to eliminate

When the substrate has pores in it so that the water vapor can pass through, the molecules of y can also pass through.

 

3.2 Mechanism which causes drawback to occur

When pores are present in the film, the dangerous gas can pass through to the other side. If there are no pores in the film, the moisture vapor builds up and leads to heat stress because it does not have any means to leave the area next to the body.

3.3 History of the development of the problem

3.4 Other problems to be solved

4.0 Changing the system

4.1 Allowing changes to the system

Any method of keeping the y molecules out of contact with the wearer while allowing moisture vapor to leave the body is acceptable. The solution is limited by nothing.

4.2 Limitations to changing the system

The means to render the y molecules harmless must be something that will act over the entire body of the person wearing the suit. It should not add any weight to the suit

5.0 Criteria for selecting solution concepts

5.1 Desired technological characteristics

The solution should be lightweight, able to be applied to the suit that the soldier already wears, low cost, patentable, usable for long periods of time, should be a level 3 invention due to the sharp contradiction present in the system.

6.0 History of attempted solutions to the problem

6.1 Previous attempts to solve the problem

Previous solutions include cooling units that were hooked up to the suit. These units did not solve the problem because they were heavy and were very costly.

ARIZ -The Algorithm of Inventive Problem Solving

Mini- Problem Formulating

1.1 Key Problem (Key knot, the "key knot " is the (a) fundamental contradiction selected to be deconstructed during this phase of the algorithm)

 

(+)

( -)

Key Condition- The substrate with cage-like molecules comes in contact with X molecules. The X molecules are captured by the CL molecules and thus prevented from crossing the substrate.

X molecules do not pass through barrier.

Moisture vapor and heat build up on side of substrate next to the soldier, causing heat stress.

1.2 Useful Function

The CD molecule bonds with the y molecules, protecting the soldier.

1.3 Harmful Function

The nonporous substrate blocks moisture vapor and heat from crossing the substrate.

1.4 Find out the Common Element(s) in the Useful and Harmful Functions

The common element in the useful and harmful functions is the substrate.

1.5 Render Graphical Scheme of the Conflict

1.6 Additional Condition where both useful and harmful functions are enhanced.

Additional Condition is: more substrate/ CD layers

1.7 The Functional Initial Contradiction

If more layers are used, more y molecules are trapped, but moisture vapor and heat have less chance of escaping from body.

1.8 Render scheme of Reverse Key Knot (The inverse of the key knot)

Film has holes in it

1.9 Graphical Scheme of Reverse Key Knot

1.10 Formulate the Functional Initial Contradiction corresponding to the Reverse Conflict

If the substrate has holes in it, (+) the moisture vapor can flow across the substrate away from the body, but (-) the dangerous molecules of y can pass through.

1.11 Formulate the Mini-Problem:

There is a Technological System for rendering harmful molecules harmless including harmful molecules y, cage-like molecules, barrier substrate, moisture vapor, and heat.

IC-1 If many layers are used, (+) all the dangerous molecules are absorbed, but (-) no moisture vapor and heat are able to travel across the barrier away from the body.

IC-2 If there are holes in the layer, (+) the moisture vapor can cross the barrier, but (-) the dangerous molecules of y are able to travel across the barrier to the body.

2.0 The Pseudo-Fundamental Contradiction Formulating and Resolving

2.1 Formulate the Pseudo- Fundamental Contradiction (PFC):

The substrate layer should have pores in it so that the moisture vapor can cross it, but it should be continuous so that no dangerous molecules of y can cross the barrier.

3.0 Conflict Enforcement

3.1 Enforce the Conflict described in the IC-1 using the Operator of the Conflict Enforcement

Very many layers so that none of the y molecules can get through the barrier.

3.2 No barrier substrate so that the MV can pass across the barrier.

Solution- A barrier is not needed if an electrical field could be induced which would be the same charge as the electric charge of y.

4.0 Formulating Directions for Solutions

4.1 Formulate the Model of Problem for the conflict IC-1:

Given that cage-like molecules, barrier substrate, y molecules, and MV participate in the conflict.

IC-1- If many layers are used (+) it prevents y from passing through, but (-) prevents MV from passing through.

4.2 Model of Problem for IC-2

Given that cage-like molecules, barrier substrate, y molecules, moisture vapor participate in the conflict.

If there are holes in the substrate, (+) moisture vapor can cross, but (-) dangerous molecules can also pass through.

         

5.0 Operational Zone Analysis

5.1 Determine the Operational Zones

UFOZ
(useful function
operating zone)

UFOZ- contains the cage-like molecules, the dangerous molecules y

HFOZ- contains the barrier substrate and the moisture vapor molecules and the dangerous molecules of y

Operational and Resource time (OT and RT) is the same time.  Everything is happening at the same time.

5.2  Substances and fields associated with both Operational Zones (Resources available       within the context of the VFOZ and HFOZ, this is a subset of the exhaustive resources indicated in step 2.0 of the ISQ.)

Dangerous substance y

Barrier substrate

Object Properties Connected with
y molecules chemical compound mechanical field
Chemical field
barrier substrate polymer mechanical field
inert

6.0   The Initial Ideal Result (IIR) Formulating

IC-1

x-resource x-resource
Prevents molecules of y from passing through the barrier of eliminates the consequences during the time of the use of the suit on the barrier substrate Allows the moisture vapor to pass across the barrier during the use of the suit on the barrier substrate
Allows the MV to pass across the barrier during the time of use on the barrier substrate Prevents molecules of y from passing through the barrier, or eliminates the consequences during the time the suit is in use on the barrier substrate.

7.0   Fundamental Contradictions Formulating

       7.1  Formulate the Brief Fundamental Contradiction

x- resource should be inside the barrier substrate during the whole time the barrier system functions to allow the passage of MV through the barrier while allowing the cage-like molecules to capture the dangerous substance y.

7.2 Formulate the Fundamental Contradiction for Process

The direct process is a mechanical barrier; this process keeps y on one side of the barrier.

The opposite process is removal of mechanical barrier.  This meets the requirement of MV transport. 

The barrier during all time of use should prevent the flow of gas y and should not prevent the flow of MV during the time of use.

Maturity Mapping

As one can see, the technology of putting CD in or on films was relatively unknown before 1976.  This technology is quickly growing, and is entering stage two of the growth curve.

 Conclusion(s):

I would like to extend my most sincere thanks to Dr. Michael Slocum and Dr. Tim Clapp for their expertise and guidance.  I enjoyed this class immensely.