How to keep unbraided long hair straight, neat and restraint the whole day at work?

I have long hair and i want to keep them open the whole day at work. I don't like braiding or pony tail or putting clips. I just want to keep them open without putting any ribbon or clip etc. Is there any way i can keep them restained the whole day and they look straight and good as well. Is there any good hair serum?How to keep unbraided long hair straight, neat and restraint the whole day at work?
You should wash it regularly using products suitable for your hair (dry, oily, etc.) and make sure it is brushed before you sleep (sorry, I'm pretty sure you already know that). If you wash your hair in the morning, dry it with paper towel if you can, and you can also apply some leave in conditioner. Hair spray or gel can help keep your hair the way you want it. If you don't want to use them just make sure it is detangled in the morning and bring a comb/brush and small mirror with you to work. When you have time, just check if your hair is still neat, if not then brush through it. If you're in the sun, wear a hat to protect your hair and you might want to put a bit of water on it now and then to make to get rid of the static. I hope that helps :)