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Abstract
This document contains the result of a lot of typing, measurements and some photographic work. Approximately 200 different containers of liquid crystal were delivered to the section Nano Structure Materials with just one old book containing all the data known about the wide range of molecular species stored in these containers. Now, the entire database has been digitalized along with the structural formulas of all the liquid crystal species that the section received
Next to creating this database, we have also tried to fill in some of the missing data, as it was far from complete. Now, it would be impossible to fill in all of the missing gaps, and we never aimed to do so. We have added a few pieces of missing detail and through this familiarized ourselves with some of the techniques used in characterization of liquid crystals. We have also recorded some images to go with the database at that point.
Now, the database can be put on the internet and everyone has the ability to use the knowledge stored once in the little, old booklet. Next to that, the section can edit the database quite easily to complete as much of the information as possible. We think that we have succeeded in making this database easy to use and readily accessible.
25-01-2008
Cees Haringa, Thiemo Pronk, Anne van de Wouw
How the database came to be
In october 2007 Prof. Dr. Ir. Wim De Jeu from Amsterdam gave the TU Delft his liquid crystal collection. With the collection came a booklet that contained their structural formulas, names and any other known information. Then three students, second year into the MST programme, came along. For their LO2 project they were tasked to create an online database of the liquid crystals.
And that’s what we did and what you can see on this site. The following text will explain exactly how the database came into existence.
We started by importing the data from the booklet into excel. We coupled the Excel worksheets to an Access database, this made searching for missing data a lot easier. However, getting the data in an online interactive database proved too much for Access. The best solution was to import the database into MySQL and then put it in a PHP framework. This means that the database was converted into another format (MySQL) that made it accessible. In order to get it online and searchable we had to use PHP, which stands for hypertext pre-processor. PHP functions as a ‘grabber’, which means that when you give it a query, it will search the database and get the right data. The make-up of the page is still html, just laced with PHP for the database function. This is what you’re looking at right now and what allows the site to function as an easily searchable database.
How to use the database
The following text will explain how to use the database and how to search it best. You can view the entire database by clicking on the database directly. You can order the database by clicking on the top of any column, just like in Access and Excel. To use the search form all you have to do is enter a query and click search. You can narrow your search by clicking on the drop down menu’s and selecting a liquid crystal category or property. You can also sort your search results by clicking on the column header.
The properties you can search for are:
• Crystal Number: This consists of a letter that stands for a base structure and a number
• Main Group: This is the main group, you can click on the main group number to see the chemical structure
• Tailgroup1: This is the group on the left side from the main group
• Tailgroup2: This is the group on the right side of the main group
• Name: Trivial name if the crystal has one
• Phase Transitions: Known phase transitions of the crystal
• Monotropic: Whether or not the LC is monotropic
• Location: Label on the container, located in Delft Chem Tech
