Cleaning ability of Washing Powders

Table of Content

INTRODUCTION

BACKGROUND INFORMATION
Washing Powders:
Detergents:
How clothes are cleaned:
Surface tension
Methods of calculating surface tension
About Stalagmometer

RESEARCH METHODOLOGY
Experiment Overview:
Hypothesis

CHOOSING AND CONTROLLING VARIABLES
Preparation of solutions:
Controlling Variables

APPARATUS

CHEMICALS REQUIRED:

PROCEDURE:

DATA COLLECTION:
Raw Data Tables
Table 1: Average integral drops of water and sodium lauryl sulphate at 25°C
Table 2: Average integral drops of water and sodium lauryl sulphate at 30°C
Table 3: Average integral drops of water and sodium lauryl sulphate at 40°C
Table 4: Average integral drops of water and sodium lauryl sulphate at 50°C
Table 5: Average integral drops of water and washing powder solutions at 25°C
Table 6: Average integral drops of water and washing powder solutions at 30°C
Table 7: Average integral drops of water and washing powder solutions at 40°C
Table 8: Average integral drops of water and washing powder solutions at 50°C

ANALYSIS:
Calculation of uncertainties
Processed Data Tables:
Table 10: Surface Tension of different concentrations of sodium lauryl sulphate solutions at 25°C
Table 11: Surface Tension of different concentrations of sodium lauryl sulphate solutions at 30°C
Table 12: Surface Tension of different concentrations of sodium lauryl sulphate solutions at 40°C
Table 13: Surface Tension of different concentrations of sodium lauryl sulphate solutions at 50°C
Table 14: Surface Tension of different washing powder solutions at 25°C
Table 15: Surface Tension of different washing powder solutions at 30°C
Table 16: Surface Tension of different washing powder solutions at 40°C
Table 17: Surface Tension of different washing powder solutions at 50°C
Table 18: Comparison of surface tensions of all solutions at the all chosen temperatures
Table 19: Calculating the correlation

PLOTTING THE GRAPH
Graph1: Surface Tensions of 5 washing powders at commonly used temperatures on WASHING MACHINES
Graph 2: Surface Tensions of different concentrations of sodium lauryl sulphate solutions at commonly used temperatures on washing machines

CONCLUSION AND EVALUATION
Discussion
Statistical significance
Limitations
Improvement

FURTHER SCOPE

BIBLIOGRAPHY

APPENDIX I
Derivation of the formula Of Surface Tension:

APPENDIX II
Safety precautions and methods of disposal:

APPENDIX III
Survey Table:

Cleaning ability of Washing Powders

To what extent is the cleaning ability, determined in terms of surface tension(mN/m), of various washing powders (Fena, Complete Ariel, Tide Plus, Henko and Ezee Liquid Detergent) with concentration 0.1%m/V and of the detergent, Sodium Lauryl Sulphate (LAS) with different concentrations (0.05%m/V, 0.1%m/V, 0.2%m/Vand 0.3%m/V) affected by an increase in temperature (25±0.5°C to 50±0.5°C)?

Abstract

Watching the washing powder advertisements, I have often wondered which really is the best washing powder, in terms of solely the cleaning action

I researched and found that the cleaning ability is a function of the surface tension and that washing powders contain surfactants or detergents like Sodium Lauryl Sulphate (LAS) that lower the surface tension. Surface tension causes the surface portion of liquid to be attracted to another surface. Thus lowering the surface tension allows the water to spread further and can penetrate into the holes and pores of the surface giving a better cleaning performance. However, these detergents only work if they are at their Critical Micelle Concentration. Keeping the CMC of LAS in mind, I took different concentrations of it so as to find the maximum value of surface tension that must be passed for effective cleaning

My research question thus states: To what extent is the cleaning ability, determined in terms of surface tension(mN/m), of various washing powders (Fena, Complete Ariel, Tide Plus, Henko and Ezee Liquid Detergent) with concentration 0.1%m/V and of the detergent, Sodium Lauryl Sulphate (LAS) with different concentrations (0.05%m/V, 0.1%m/V, 0.2%m/V and 0.3%m/V) affected by an increase in temperature (25±0.5°C to 50±0.5°C)?

The number of drops of water and washing powder solutions was found at determined temperatures and using a formula the surface tension was calculated. The result of this study was that at higher temperatures along with higher concentrations of detergents, reduced the surface tension and thus gives higher cleaning performance. Using the results it was determined that Henko washing powder gives the best cleaning performance at all temperatures with the lowest surface tension of 17.29 mN/m at 50°C. Whereas Ezee Liquid Detergent gave the comparatively poorest cleaning performance at all temperatures with the highest surface tension of 50.41mN/m at 25°C

Introduction

Cleaning clothes is an important activity that is carried out in households all over the world. And thus, washing powders are significant to a households expense.

Every household is economically and regionally different, but one question persists everywhere: “Which is the better detergent?”. Choosing the right detergent is often a dilemma all homemakers must overcome. With more and more detergent brands coming in, of both powder and liquid form, and with extreme promotional strategies, answering this question gets more challenging. People try to answer this question based on the detergents cleaning ability, its price, its promotional offers and its customer services. However, as a science student, the better detergent should be determined based on its cleaning ability.

In the local market of Jaipur one will come across 17 different brands of washing powders. (Ariel Antibac, Active Wheel, Ghari, Surf Excel Easy Wash, Tide Plus, Fena, Henko, Genteel, Surf Excel Matic, Complete Ariel, Ezee Liquid Detergent, Surf Excel Blue Liquid, 555,Rin Refresh, Pearl Laundry Wash, Amway, and Nirma) I conducted a survey with 284 students of class 10, 11 and 12 and asked them the washing powder they use. The top 5 commonly used detergents, as concluded from the survey were, Ezee Liquid Detergent, Fena, Complete Ariel, Tide Plus, and Henko.

The cleaning action of detergents is affected by various factors like solubility, Ph., surface tension, and hardness of water. As a student of both chemistry and physics, I choose to study the effect of surface tension on the cleaning ability of a detergent. The surface tension depends on temperature, surface area, external pressure, and concentration. To find out the surface tension I will vary the temperature while keeping the other constant.

Thus, my research question states: To what extent is the cleaning ability, determined in terms of surface tension(mN/m), of various washing powders (Fena, Complete Ariel, Tide Plus, Henko and Ezee Liquid Detergent) with concentration 0.1%m/V and of the detergent, Sodium Lauryl Sulphate (LAS) with different concentrations (0.05%m/V, 0.1%m/V, 0.2%m/V and 0.3%m/V) affected by an increase in temperature (25±0.5°C to 50±0.5°C)?

With the research in this topic, I shall conclude which one of the most popular washing powder has the maximum cleansing ability.

Background Information

Washing Powders:

Washing powders, these days are composed of the under-mentioned continents.

Oxidizers are used to whiten the clothes and they further produce chemical reactions by using the oxygen molecules from water. Surfactants (detergents) are surface-active agents that lower the surface tension of the water and thus help to remove the dirt and grease from the surface of the clothes. Common surfactants are Linear Alkyl Sulphate and Sodium Dodecyl benzene Sulphonate. Water softeners are present in the washing powders, since surfactants are more effective in soft water. Enzymes are a part of the detergents as they allow the surfactants to attach to dirt more effectively by using molecular process to dissolve proteins, fats and starches. Builders like Sodium Carbonate, Sodium Tripolyphosphate are are substances that soften water and regulate the pH level for better emulsification of oils. Fillers like Sodium Chloride and Borax are substances that better the cleaning action of the detergents as they dilute and further distribute the active ingredients. Material-Anti­Redeposition Agents like Cellulose Esters and Ethers are added to the washing powders to prevent any further deposition of dirt and grease on the clothes. It also prevents the removed dirt to get re­attached to the clothes. Further additives like perfumes, bleaches, Blue dyes and Fluorescent whiteners are added to de-colorize the stains, prevent yellowing and whiten the clothes.

Detergents:

Linear Alkyl Benzene Sulphonate (LAS) is an anionic surfactant used in nearly all kinds of washing powders, liquids and household cleaners. In most cases LAS is used as a sodium derivative. The most popular LAS today is Sodium Lauryl Sulphate. LAS have been developed from Linear Alkyl Benzene (LAB). Approximately 99% of the LAB produced worldwide is transformed into LAS through a sulphonation process^[1].

illustration not visible in this excerpt

LAS are highly compatible and are the most efficient in terms of cost performance ratio. With a low toxicity profile, LAS are designed in such a manner that they biodegrade promptly post the discharge of liquids from the washing machines.

As a matter of fact LAS has replaced the branched Dodecyl Benzene Sulphonates because of their biodegradable nature.

How clothes are cleaned:

All detergents have polar ionic hydrophilic heads and long hydrocarbon hydrophobic tails. When in water, these hydrophilic heads interact with the hydrogen bonds of the water and the tails being hydrophobic repel water molecules but are attracted to the grease and the oil on the clothes. Thus they both form a unique organized spherical structure called micelles at the Critical Micelle Concentration(CMC). After agitations and rinsing, the detergents pull away the dirt and it gets suspended in water.^[2]

If the micelles are formed, then only the cleaning of the clothes will take place. Thus, if the concentration of a detergent in a washing powder is below the CMC, the cleaning of the clothes will not take place. Furthermore, the micelle formation decreases the surface tension.

illustration not visible in this excerpt

Surface tension

It is a physical property equal to the amount of force per unit area necessary to expand the surface of a liquid^{[3] [4]}. The effects of intermolecular forces at the interface cause surface tension. This means that liquids which have large intermolecular forces, will thus have a large surface tension. The cleaning performance is a function of surface tension.

Methods of calculating surface tension

There are various methods of calculating the surface tension namely Capillary Rise Method, Spinning Drop Method, Wilhelmy Plate Method, Pendent Drop Method, Jagger’s Method, Drop Volume Method, Du Noüy Ring Detachment Method, Stalagmometer Drop Weight Method and, Stalagmometer Drop Number Method. I shall be using the Drop number method using Traube’s Stalagmometer technique because it has an easy approach and involves little topics of physics.

[...]

^[1] 'ECOSOL. "Chemistry of LAS." Lasinfo. ECOSOL, n.d. Web. 28 Oct. 2015. <http://www.lasinfo.eu/index.php/what-is-las/chemistry-of-las>.

^[2] ECOSOL. "Chemistry of LAS." Lasinfo. ECOSOL, n.d. Web. 28 Oct. 2015. <http://www.lasinfo.eu/index.php/what-is-las/chemistry-of-las>.

^[3] Cruzan, Jeff. "Acids & Bases." Acids & Bases. Xaktly.com, 2012. Web. 30 Oct. 2015. <http://www.drcruzan.com/Water.html>.

^[4] Helmenstine, Anne Marie. "What Is Surface Tension?" Surface Tension Definition. About.com Education, 29 Nov. 2014. Web. 2 Nov. 2015. <http://chemistry.about.com/od/chemistryglossary/g/Surface-Tension-Definition.htm>.